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Alternate Formats: rfc2297.txt | rfc2297.txt.pdf
RFC 2297 - Ipsilon's General Switch Management Protocol Specification Version 2.0
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RFC2297 - Ipsilon's General Switch Management Protocol Specific
Network Working Group P. Newman, Nokia
Request for Comments: 2297 W. Edwards, Sprint
Updates: 1987 R. Hinden, Nokia
Category: Informational E. Hoffman, Nokia
F. Ching Liaw
T. Lyon, Nokia
G. Minshall, Fiberlane
March 1998
Ipsilon's General Switch Management Protocol Specification
Version 2.0
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
This memo specifies enhancements to the General Switch Management
Protocol (GSMP) [RFC1987]. The major enhancement is the addition of
Quality of Service (QoS) messages. Other improvements have been made
to the protocol resulting from operational experience. GSMP is a
general purpose protocol to control an ATM switch. It allows a
controller to establish and release connections across the switch;
add and delete leaves on a multicast connection; manage switch ports;
request configuration information; and request statistics.
Table of Contents
1. Introduction....................................................3
2. GSMP Packet Encapsulation.......................................4
2.1 ATM Encapsulation...........................................4
2.2 Ethernet Encapsulation......................................6
3. Common Definitions and Procedures...............................7
3.1 GSMP Packet Format..........................................8
3.2 Failure Response Messages..................................11
4. Connection Management Messages.................................16
4.1 Add Branch Message.........................................21
4.2 Delete Tree Message........................................23
4.3 Verify Tree Message........................................24
4.4 Delete All Message.........................................24
4.5 Delete Branches Message....................................25
4.6 Move Branch Message........................................27
5. Port Management Messages.......................................29
5.1 Port Management Message....................................29
5.2 Label Range Message........................................34
6. State and Statistics Messages..................................37
6.1 Connection Activity Message................................38
6.2 Statistics Messages........................................40
6.2.1 Port Statistics Message..............................44
6.2.2 Connection Statistics Message........................44
6.2.3 QoS Class Statistics Message.........................44
6.3 Report Connection State Message............................45
7. Configuration Messages.........................................49
7.1 Switch Configuration Message...............................50
7.2 Port Configuration Message.................................51
7.3 All Ports Configuration Message............................57
8. Event Messages.................................................59
8.1 Port Up Message............................................60
8.2 Port Down Message..........................................60
8.3 Invalid VPI/VCI Message....................................61
8.4 New Port Message...........................................61
8.5 Dead Port Message..........................................61
9. Quality of Service Messages....................................61
9.1 Abstract Switch Model......................................62
9.2 QoS Configuration Message..................................66
9.3 Scheduler Establishment Message............................74
9.4 QoS Class Establishment Message............................78
9.5 QoS Release Message........................................85
9.6 QoS Connection Management Message..........................86
9.7 QoS Failure Response Codes.................................97
10. Adjacency Protocol............................................97
10.1 Packet Format.............................................98
10.2 Procedure.................................................101
10.3 Loss of Synchronization...................................103
11. Summary of Failure Response Codes.............................104
12. Summary of Message Set........................................105
References........................................................107
Security Considerations...........................................107
Authors' Addresses................................................107
Full Copyright Statement..........................................109
1. Introduction
The General Switch Management Protocol (GSMP), is a general purpose
protocol to control an ATM switch. GSMP allows a controller to
establish and release connections across the switch; add and delete
leaves on a multicast connection; manage switch ports; request
configuration information; and request statistics. It also allows the
switch to inform the controller of asynchronous events such as a link
going down. GSMP runs across an ATM link connecting the controller to
the switch, on a control connection (virtual channel) established at
initialization. GSMP operation across an Ethernet link is also
specified. The GSMP protocol is asymmetric, the controller being the
master and the switch being the slave. Multiple switches may be
controlled by a single controller using multiple instantiations of
the protocol over separate control connections.
A switch is assumed to contain multiple "ports". Each port is a
combination of one "input port" and one "output port". Some GSMP
requests refer to the port as a whole whereas other requests are
specific to the input port or the output port. ATM cells arrive at
the switch from an external communication link on incoming virtual
paths or virtual channels at an input port. ATM cells depart from the
switch to an external communication link on outgoing virtual paths or
virtual channels from an output port. Virtual paths on a port or link
are referenced by their virtual path identifier (VPI). Virtual
channels on a port or link are referenced by their virtual path and
virtual channel identifiers (VPI/VCI).
A virtual channel connection across a switch is formed by connecting
an incoming virtual channel to one or more outgoing virtual channels.
Virtual channel connections are referenced by the input port on which
they arrive and the virtual path and virtual channel identifiers
(VPI/VCI) of their incoming virtual channel. A virtual path
connection across a switch is formed by connecting an incoming
virtual path to one or more outgoing virtual paths. Virtual path
connections are referenced by the input port on which they arrive and
their virtual path identifier (VPI). In a virtual path connection
the value of the VCI in each cell on that, connection is not used by
the switch and remains unchanged by the switch.
GSMP supports point-to-point and point-to-multipoint connections. A
multipoint-to-point connection is specified by establishing multiple
point-to-point connections each of them specifying the same output
branch. A multipoint-to-multipoint connection is specified by
establishing multiple point-to-multipoint trees each of them
specifying the same output branches.
In general a virtual channel is established with a certain quality of
service (QoS). A rich set of QoS messages is introduced in this
version of the protocol. However, implementation or operation of GSMP
without any of the messages defined in Section 9, "Quality of service
messages," is permitted. In this case each virtual channel
connection or virtual path connection may be assigned a priority when
it is established. It may be assumed that for virtual connections
that share the same output port, an ATM cell on a connection with a
higher priority is much more likely to exit the switch before an ATM
cell on a connection with a lower priority if they are both in the
switch at the same time. The number of priorities that each port of
the switch supports may be obtained from the port configuration
message.
GSMP contains an adjacency protocol. The adjacency protocol is used
to synchronize state across the link, to negotiate which version of
the GSMP protocol to use, to discover the identity of the entity at
the other end of a link, and to detect when it changes.
2. GSMP Packet Encapsulation
2.1 ATM Encapsulation
GSMP packets are variable length and for an ATM data link layer they
are encapsulated directly in an AAL-5 CPCS-PDU [I.363] with an
LLC/SNAP header as illustrated:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LLC (0xAA-AA-03) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| SNAP (0x00-00-00-88-0C) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ GSMP Message ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad (0 - 47 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ AAL-5 CPCS-PDU Trailer (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(The convention in the documentation of Internet Protocols [RFC1700]
is to express numbers in decimal. Numbers in hexadecimal format are
specified by prefacing them with the characters "0x". Data is
pictured in "big-endian" order. That is, fields are described left to
right, with the most significant octet on the left and the least
significant octet on the right. Whenever a diagram shows a group of
octets, the order of transmission of those octets is the normal order
in which they are read in English. Whenever an octet represents a
numeric quantity the left most bit in the diagram is the high order
or most significant bit. That is, the bit labeled 0 is the most
significant bit. Similarly, whenever a multi-octet field represents a
numeric quantity the left most bit of the whole field is the most
significant bit. When a multi-octet quantity is transmitted, the most
significant octet is transmitted first. This is the same coding
convention as is used in the ATM layer [I.361] and AAL-5 [I.363].)
The LLC/SNAP header contains the octets: 0xAA 0xAA 0x03 0x00 0x00
0x00 0x88 0x0C. (0x880C is the assigned Ethertype for GSMP.)
The maximum transmission unit (MTU) of the GSMP Message field is 1492
octets.
The virtual channel over which a GSMP session is established between
a controller and the switch it is controlling is called the GSMP
control channel. The default VPI and VCI of the GSMP control channel
for LLC/SNAP encapsulated GSMP messages on an ATM data link layer is:
VPI = 0
VCI = 15.
2.2 Ethernet Encapsulation
GSMP packets may be encapsulated on an Ethernet data link as
illustrated:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Address |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ethertype (0x88-0C) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
~ GSMP Message ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Instance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receiver Instance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Frame Check Sequence |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Destination Address
For the SYN message of the adjacency protocol the
Destination Address is the broadcast address
0xFFFFFFFFFFFF. (Alternatively, it is also valid to
configure the node with the unicast 48-bit IEEE MAC address
of the destination. In this case the configured unicast
Destination Address is used in the SYN message.) For all
other messages the Destination Address is the unicast 48-
bit IEEE MAC address of the destination. This address may
be discovered from the Source Address field of messages
received during synchronization of the adjacency protocol.
Source Address
For all messages the Source Address is the 48-bit IEEE MAC
address of the sender.
Ethertype
The assigned Ethertype for GSMP is 0x880C.
GSMP Message
The maximum transmission unit (MTU) of the GSMP Message
field is 1492 octets.
Sender Instance
The Sender Instance number for the link obtained from the
adjacency protocol. This field is already present in the
adjacency protocol message. It is appended to all non-
adjacency GSMP messages in the Ethernet encapsulation to
offer additional protection against the introduction of
corrupt state.
Receiver Instance
The Receiver Instance number is what the sender believes is
the current instance number for the link, allocated by the
entity at the far end of the link. This field is already
present in the adjacency protocol message. It is appended
to all non-adjacency GSMP messages in the Ethernet
encapsulation to offer additional protection against the
introduction of corrupt state.
Pad
The minimum length of the data field of an Ethernet packet
is 46 octets. If necessary, padding should be added such
that it meets the minimum Ethernet frame size. This padding
should be octets of zero and it is not considered to be
part of the GSMP message.
After the adjacency protocol has achieved synchronization, for every
GSMP message received with an Ethernet encapsulation, the receiver
must check the Source Address from the Ethernet MAC header, the
Sender Instance, and the Receiver Instance. The incoming GSMP
message must be discarded if the Sender Instance and the Source
Address do not match the values of Sender Instance and Sender Name
stored by the "Update Peer Verifier" operation of the GSMP adjacency
protocol. The incoming GSMP message must also be discarded if it
arrives over any port other than the port over which the adjacency
protocol has achieved synchronization. In addition, the incoming
message must also be discarded if the Receiver Instance field does
not match the current value for the Sender Instance of the GSMP
adjacency protocol.
3. Common Definitions and Procedures
GSMP is a master-slave protocol. The controller issues request
messages to the switch. Each request message indicates whether a
response is required from the switch and contains a transaction
identifier to enable the response to be associated with the request.
The switch replies with a response message indicating either a
successful result or a failure. There are five classes of GSMP
request-response message: Connection Management, Port Management,
State and Statistics, Configuration, and Quality of Service. The
switch may also generate asynchronous Event messages to inform the
controller of asynchronous events. Event messages are not
acknowledged by the controller. There is also an adjacency protocol
message used to establish synchronization across the link and
maintain a handshake.
For the request-response messages, each message type has a format for
the request message and a format for the success response. Unless
otherwise specified a failure response message is identical to the
request message that caused the failure, with the Code field
indicating the nature of the failure. Event messages have only a
single format defined as they are not acknowledged by the controller.
Switch ports are described by a 32-bit port number. The switch
assigns port numbers and it may typically choose to structure the 32
bits into subfields that have meaning to the physical structure of
the switch (e.g. slot, port). In general, a port in the same physical
location on the switch will always have the same port number, even
across power cycles. The internal structure of the port number is
opaque to the GSMP protocol. However, for the purposes of network
management such as logging, port naming, and graphical
representation, a switch may declare the physical location (physical
slot and port) of each port. Alternatively, this information may be
obtained by looking up the product identity in a database.
Each switch port also maintains a port session number assigned by the
switch. A message, with an incorrect port session number must be
rejected. This allows the controller to detect a link failure and to
keep state synchronized.
Except for the adjacency protocol message, no GSMP messages may be
sent across the link until the adjacency protocol has achieved
synchronization, and all GSMP messages received on a link that does
not currently have state synchronization must be discarded.
3.1 GSMP Packet Format
All GSMP messages, except the adjacency protocol message, have the
following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Message Body ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Version
The version number of the GSMP protocol being used in this
session. It should be set by the sender of the message to
the GSMP protocol version negotiated by the adjacency
protocol.
Message Type
The GSMP message type. GSMP messages fall into six classes:
Connection Management, Port Management, State and
Statistics, Configuration, Quality of Service, and Events.
Each class has a number of different message types. In
addition, one Message Type is allocated to the adjacency
protocol.
Result
Field in a Connection Management request message, a Port
Management request message, or a Quality of Service request
message is used to indicate whether a response is required
to the request message if the outcome is successful. A
value of "NoSuccessAck" indicates that the request message
does not expect a response if the outcome is successful,
and a value of "AckAll" indicates that a response is
expected if the outcome is successful. In both cases a
failure response must be generated if the request fails.
For Sate and Statistics, and Configuration request
messages, a value of "NoSuccessAck" in the request message
is ignored and the request message is handled as if the
field were set to "AckAll". (This facility was added to
reduce the control traffic in the case where the controller
periodically checks that the state in the switch is
correct. If the controller does not use this capability,
all request messages should be sent with a value of
"AckAll.")
In a response message the result field can have three
values: "Success," "More," and "Failure". The "Success" and
"More" results both indicate a success response. The "More"
result indicates that the success response exceeds the
maximum transmission unit of the data link and that one or
more further messages will be sent to complete the success
response. All messages that belong to the same success
response will have the same Transaction Identifier. The
"Success" result indicates a success response that may be
contained in a single message or the final message of a
success response spanning multiple messages.
The encoding of the result field is:
NoSuccessAck: Result = 1
AckAll: Result = 2
Success: Result = 3
Failure: Result = 4
More: Result = 5.
The Result field is not used in an adjacency protocol
message.
Code
Field gives further information concerning the result in a
response message. It is mostly used to pass an error code
in a failure response but can also be used to give further
information in a success response message or an event
message. In a request message the code field is not used
and is set to zero. In an adjacency protocol message the
Code field is used to determine the function of the
message.
Transaction Identifier
Used to associate a request message with its response
message. For request messages the controller may select any
transaction identifier. For response messages the
transaction identifier is set to the value of the
transaction identifier from the message to which it is a
response. For event messages the transaction identifier
should be set to zero. The Transaction Identifier is not
used, and the field is not present, in the adjacency
protocol.
The following fields are frequently found in GSMP messages. They are
defined here to avoid repetition.
Port
Gives the port number of the switch port to which the
message applies.
Port Session Number
Each switch port maintains a Port Session Number assigned
by the switch. The port session number of a port remains
unchanged while the port is continuously in the Available
state and the link status is continuously Up. When a port
returns to the Available state after it has been
Unavailable or in any of the Loopback states, or when the
line status returns to the Up state after it has been Down
or in Test, or after a power cycle, a new Port Session
Number must be generated. Port session numbers should be
assigned using some form of random number.
If the Port Session Number in a request message does not
match the current Port Session Number for the specified
port, a failure response message must be returned with the
Code field indicating, "Invalid port session number." The
current port session number for a port may be obtained
using a Port Configuration or an All Ports Configuration
message.
Any field in a GSMP message that is unused or defined as "reserved"
must be set to zero by the sender and ignored by the receiver.
It is not an error for a GSMP message to contain additional data
after the end of the Message Body. This is to support development and
experimental purposes. However, the maximum transmission unit of the
GSMP message, as defined by the data link layer encapsulation, must
not be exceeded.
A success response message must not be sent until the requested
operation has been successfully completed.
3.2 Failure Response Messages
A failure response message is formed by returning the request message
that caused the failure with the Result field in the header
indicating failure (Result = 4) and the Code field giving the failure
code. The failure code specifies the reason for the switch being
unable to satisfy the request message.
If the switch issues a failure response in reply to a request
message, no change should be made to the state of the switch as a
result of the message causing the failure. (For request messages that
contain multiple requests, such as the Delete Branches message, the
failure response message will specify which requests were successful
and which failed. The successful requests may result in changed
state.)
If the switch issues a failure response it must choose the most
specific failure code according to the following precedence:
Invalid Message
Failure specific to the particular message type (failure code
16). (The meaning of this failure is dependent upon the
particular message type and is specified in the text defining
the message.)
A failure response specified in the text defining the message
type.
Connection Failures
Virtual Path Connection Failures
Multicast Failures
QoS Failures (QoS failures are specified in Section 9.7.)
General Failures
If multiple failures match in any of the following categories, the
one that is listed first should be returned. The following failure
response messages and failure codes are defined:
Invalid Message
3: The specified request is not implemented on this switch.
The Message Type field specifies a message that is not
implemented on the switch or contains a value that is not
defined in the version of the protocol running in this
session of GSMP.
5: One or more of the specified ports does not exist.
At least one of the ports specified in the message is
invalid. A port is invalid if it does not exist or if it
has been removed from the switch.
4: Invalid Port Session Number.
The value given in the Port Session Number field does not
match the current Port Session Number for the specified
port.
Connection Failures
8: The specified connection does not exist.
An operation that expects a connection to be specified,
either a virtual channel or a virtual path connection,
cannot locate the specified connection. A virtual channel
connection is specified by the input port, input VPI, and
input VCI on which it arrives. A virtual path connection
is specified by the input port and input VPI on which it
arrives.
9: The specified branch does not exist.
An operation that expects a branch of an existing
connection to be specified, either a virtual channel or a
virtual path connection, cannot locate the specified
branch. A branch of a virtual channel connection is
specified by the virtual channel connection it belongs to
and the output port, output VPI, and output VCI on which
it departs. A branch of a virtual path connection is
specified by the virtual path connection it belongs to
and the output port and output VPI on which it departs.
18: One or more of the specified input VPIs is invalid.
19: One or more of the specified input VCIs is invalid.
20: One or more of the specified output VPIs is invalid.
21: One or more of the specified output VCIs is invalid.
22: Invalid Class of Service field in a Connection Management
message.
The value of the Class of Service field is invalid.
23: Insufficient resources for QoS Profile.
The resources requested by the QoS Profile in the Class
of service field are not available.
Virtual Path Connections
24: Virtual path switching is not supported on this input port.
25: Point-to-multipoint virtual path connections are not
supported on either the requested input port or the
requested output port.
One or both of the requested input and output ports is
unable to support point-to-multipoint virtual path
connections.
26: Attempt to add a virtual path connection branch to an
existing virtual channel connection.
It is invalid to mix branches switched as virtual channel
connections with branches switched as virtual path
connections on the same point-to-multipoint connection.
27: Attempt to add a virtual channel connection branch to an
existing virtual path connection.
It is invalid to mix branches switched as virtual channel
connections with branches switched as virtual path
connections on the same point-to-multipoint connection.
Multicast Failures
10: A branch belonging to the specified point-to-multipoint
connection is already established on the specified output
port and the switch cannot support more than a single
branch of any point-to-multipoint connection on the same
output port.
11: The limit on the maximum number of point-to-multipoint
connections that the switch can support has been reached.
12: The limit on the maximum number of branches that the
specified point-to-multipoint connection can support has
been reached.
17: Cannot label each output branch of a point-to-multipoint tree
with a different label.
Some early designs, and some low-cost ATM switch designs,
require all output branches of a multicast connection to
use the same value of VPI/VCI.
28: Only point-to-point bidirectional connections may be
established.
It is an error to attempt to add an additional output
branch to an existing connection with the bidirectional
flag set.
13: Unable to assign the requested VPI/VCI value to the requested
branch on the specified point-to-multipoint connection.
Although the requested VPI and VCI are valid, the switch
is unable to support the request using the specified
values of VPI and VCI for some reason not covered by the
above failure responses. This message implies that a
valid value of VPI or VCI exists that the switch could
support. For example, some switch designs restrict the
number of distinct VPI/VCI values available to a point-
to-multipoint connection. (Most switch designs will not
require this message.)
14: General problem related to the manner in which point-to-
multipoint is supported by the switch.
Use this message if none of the more specific multicast
failure messages apply. (Most switch designs will not
require this message.)
General Failures
2: Invalid request message.
There is an error in one of the fields of the message not
covered by a more specific failure message.
6: One or more of the specified ports is down.
A port is down if its Port Status is Unavailable.
Connection Management, Connection State, Port Management,
and Configuration operations are permitted on a port that
is Unavailable. Connection Activity and Statistics
operations are not permitted on a port that is
Unavailable and will generate this failure response. A
Port Management message specifying a Take Down function
on a port already in the Unavailable state will also
generate this failure response.
15: Out of resources.
The switch has exhausted a resource not covered by a more
specific failure message, for example, running out of
memory.
1: Unspecified reason not covered by other failure codes.
The failure message of last resort.
The following failure response messages are only used by the Label
Range message.
29: Cannot support requested VPI range.
30: Cannot support requested VCI range on all requested VPIs.
The following failure response messages are only used by the Set
Transmit Cell Rate function of the Port Management
message.
31: The transmit cell rate of this output port cannot be changed.
32: Requested transmit cell rate out of range for this output
port.
4. Connection Management Messages
Connection management messages are used by the controller to
establish, delete, modify and verify virtual channel connections and
virtual path connections across the switch. The Add Branch, Delete
Tree, and Delete All connection management messages have the
following format for both request and response messages:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|M|Q|B|C| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| Output VPI | Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Branches | Class of Service |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Identifies a switch input port.
Flags
M: Multicast
The Multicast flag is used as a hint for point-to-
multipoint connections in the Add Branch message. It is not
used in any other connection management messages and in
these messages it should be set to zero. If set, it
indicates that the virtual channel connection or the
virtual path connection is very likely to be a point-to-
multipoint connection. If zero, it indicates that this
connection is very likely to be a point-to-point connection
or is unknown.
The Multicast flag is only used in the Add Branch message
when establishing the first branch of a new connection. It
is not required to be set when establishing subsequent
branches of a point-to-multipoint connection and on such
connections it should be ignored by the receiver. (On
receipt of the second and subsequent Add Branch messages
the receiver knows that this is a point-to-multipoint
connection.) If it is known that this is the first branch
of a point-to-multipoint connection this flag should be
set. If it is unknown, or if it is known that the
connection is point-to-point this flag should be zero. The
use of this flag is not mandatory. It may be ignored by the
switch. If unused the flag should be set to zero. Some
switches use a different data structure for point-to-
multipoint connections than for point-to-point connections.
This flag avoids the switch setting up a point-to-point
structure for the first branch of a point-to-multipoint
connection which must immediately be deleted and
reconfigured as point-to-multipoint when the second branch
is established.
Q: QoS Profile
The QoS Profile flag, if set, indicates that the Class of
Service field contains a QoS Profile Identifier. If this
flag is zero, it indicates that the Class of Service field
contains a Priority or a Scheduler Identifier.
B: Bidirectional
The Bidirectional flag applies only to the Add Branch
message. In all other Connection Management messages it is
not used. It may only be used when establishing a point-
to-point connection. The Bidirectional flag in an Add
Branch message, if set, requests that two unidirectional
virtual channels or virtual paths be established, one in
the forward direction, and one in the reverse direction. It
is equivalent to two Add Branch messages, one specifying
the forward direction, and one specifying the reverse
direction. The forward direction uses the values of Input
Port, Input VPI, Input VCI, Output Port, Output VPI, and
Output VCI as specified in the Add Branch message. The
reverse direction is derived by exchanging the values
specified in the Input Port, Input VPI, and Input VCI
fields, with those of the Output Port, Output VPI, and
Output VCI fields respectively. Thus, a virtual connection
in the reverse direction arrives at the input port
specified by the Output Port field, on the VPI/VCI
specified by the Output VPI and Output VCI fields. It
departs from the output port specified by the Input Port
field, on the VPI/VCI specified by the Input VPI and Input
VCI fields.
The Bidirectional flag is simply a convenience to establish
two unidirectional virtual connections in opposite
directions between the same two ports, with identical
VPI/VCIs, using a single Add Branch message. In all future
messages the two unidirectional virtual connections must be
handled separately. There is no bidirectional delete
message. However, a single Delete Branches message with two
Delete Branch Elements, one for the forward connection and
one for the reverse, may be used.
C: Congestion Indication
The Congestion Indication flag, if set, requests that cells
on this connection be marked if congestion is experienced.
If this connection passes through a queue that the switch
considers to be congested, the Congestion Experienced bit
will be set in the Payload Type field of the cell header of
all cells on the connection. GSMP does not specify the
algorithm or any threshold by which the switch decides when
a queue is congested.
Input VPI
Identifies an ATM virtual path arriving at the switch input
port indicated by the Input Port field.
Input VCI
Identifies an ATM virtual channel arriving on the virtual
path indicated by the Input VPI field at the switch input
port indicated by the Input Port field. For virtual path
connections the Input VCI field is not used.
Output Port
Identifies a switch output port.
x: Unused
Output VPI
Identifies an outgoing virtual path departing from the
switch output port indicated in the Output Port field.
Output VCI
Identifies an outgoing virtual channel departing on the
virtual path indicated by the Output VPI field from the
switch output port indicated in the Output Port field. For
virtual path connections the Output VCI field is not used.
Number of Branches
In a success response message and a failure response
message, gives the number of output branches on a virtual
channel connection or a virtual path connection after
completion of the requested operation. (A point-to-point
connection will have one branch, a point-to-multipoint
connection will have two or more branches.) If the switch
is unable to keep track of the number of branches on a
virtual path connection or a virtual channel connection it
must respond with the value 0xFFFF meaning: "number of
branches unknown". This field is not used in the request
message.
Class of Service
This field can contain either a QoS Profile Identifier, a
Priority, or a Scheduler Identifier. If the QoS Profile
flag in the Flags field is set, the Class of Service field
contains a QoS Profile. If the QoS Profile flag in the
Flags field is zero, and the value of the Class of Service
field is greater than or equal to 0x100, the Class of
Service field contains a Scheduler Identifier. If the QoS
Profile flag in the Flags field is zero, and the value of
the Class of Service field is less than 0x100, the Class of
Service field contains a Priority. (Values of Scheduler
Identifier less than 0x100 are interpreted as priorities.)
The Class of Service field is only used in the Add Branch
and Move Branch messages.
A QoS Profile Identifier is an opaque 16-bit value. It is
used to identify a QoS profile in the switch which
specifies the Quality of Service required by the
connection. QoS profiles are established by a mechanism
external to GSMP.
A Scheduler Identifier is an alternative method of
communicating the QoS requirements of a connection. The
Scheduler Identifier is defined in Section 9, "Quality of
Service Messages."
A Priority specifies the priority of the connection for Add
Branch and Move Branch messages that choose not to use a
QoS profile, or the QoS capabilities defined in Section 9,
"Quality of Service Messages." The highest priority is
numbered zero and the lowest priority is numbered "Q-1"
where "Q" is the number of priorities that the output port
can support. The ability to offer different qualities of
service to different connections based upon their priority
is assumed to be a property of the output port of the
switch. It is assumed that for virtual path connections or
virtual channel connections that share the same output
port, an ATM cell on a connection with a higher priority is
much more likely to exit the switch before an ATM cell on a
connection with a lower priority, if they are both in the
switch at the same time. The number of priorities that each
output port can support is given in the Port Configuration
message.
For all connection management messages, except the Delete Branches
message, the success response message is a copy of the request
message returned with the Result field indicating success and the
Number of Branches field indicating the number of branches on the
connection after completion of the operation. The Code field is not
used in a connection management success response message.
The failure response message is a copy of the request message
returned with a Result field indicating failure and the Number of
Branches field indicating the number of branches on the connection.
Fundamentally, no distinction is made between point-to-point and
point-to-multipoint connections. By default, the first Add Branch
message for a particular Input Port, Input VPI, and Input VCI will
establish a point-to-point virtual connection. The second Add Branch
message with the same Input Port, Input VPI, and Input VCI fields
will convert the connection to a point-to-multipoint virtual
connection with two branches. (For virtual path connections the Input
VCI is not required.) However, to avoid possible inefficiency with
some switch designs, the Multicast Flag is provided. If the
controller knows that a new connection is point-to-multipoint when
establishing the first branch, it may indicate this in the Multicast
Flag. Subsequent Add Branch messages with the same Input Port, Input
VPI, and Input VCI fields will add further branches to the point-to-
multipoint connection. Use of the Delete Branch message on a point-
to-multipoint connection with two branches will result in a point-
to-point connection. However, the switch may structure this
connection as a point-to-multipoint connection with a single output
branch if it chooses. (For some switch designs this structure may be
more convenient.) Use of the Delete Branch message on a point-to-
point connection will delete the point-to-point connection. There is
no concept of a connection with zero output branches. All connections
are unidirectional, one input virtual path or virtual channel to one
or more output virtual paths or virtual channels.
GSMP supports point-to-point and point-to-multipoint connections. A
multipoint-to-point connection is specified by establishing multiple
point-to-point connections each of them specifying the same output
branch. (An output branch is specified by an output port and output
VPI for a virtual path connection and by an output port, output VPI,
and output VCI for a virtual channel connection.) A multipoint-to-
multipoint connection is specified by establishing multiple point-
to-multipoint trees each of them specifying the same output branches.
The connection management messages apply both to virtual channel
connections and virtual path connections. The Add Branch and Move
Branch connection management messages have two Message Types. One
Message Type indicates that a virtual channel connection is required,
and the other Message Type indicates that a virtual path connection
is required. The Delete Branches, Delete Tree, and Delete All
connection management messages have only a single Message Type
because they do not need to distinguish between virtual channel
connections and virtual path connections. For virtual path
connections, neither Input VCI fields nor Output VCI fields are
required. They should be set to zero by the sender and ignored by the
receiver. Virtual channel branches may not be added to an existing
virtual path connection. Conversely, virtual path branches may not
be added to an existing virtual channel connection. In the Port
Configuration message each switch input port may declare whether it
is capable of supporting virtual path switching (i.e. accepting
connection management messages requesting virtual path connections).
The connection management messages may be issued regardless of the
Port Status of the switch port. Connections may be established or
deleted when a switch port is in the Available, Unavailable, or any
of the Loopback states. However, all connection state on an input
port will be deleted when the port returns to the Available state
from any other state, i.e. when a Port Management message is received
for that port with the Function field indicating either Bring Up, or
Reset Input Port.
4.1 Add Branch Message
The Add Branch message is a connection management message used to
establish a virtual channel connection or a virtual path connection
or to add an additional branch to an existing virtual channel
connection or virtual path connection. It may also be used to check
the connection state stored in the switch. The connection is
specified by the Input Port, Input VPI, and Input VCI fields. The
output branch is specified by the Output Port, Output VPI, and Output
VCI fields. The quality of service requirements of the connection are
specified by the Class of Service field. To request a virtual channel
connection the Virtual Channel Connection (VCC) Add Branch message
is:
Message Type = 16
To request a virtual path connection the Virtual Path Connection
(VPC) Add Branch message is:
Message Type = 26
If a VPC Add Branch message is received and the switch input port
specified by the Input Port field does not support virtual path
switching, a failure response message must be returned indicating,
"Virtual path switching is not supported on this input port."
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields; or the virtual path connection specified
by the Input Port and Input VPI fields; does not already exist, it
must be established with the single output branch specified in the
request message. If the Bidirectional Flag in the Flags field is set,
the reverse connection must also be established. The output branch
should have the QoS attributes specified by the Class of Service
field.
For the VCC Add Branch message, if a virtual path connection already
exists on the virtual path specified by the Input Port and Input VPI
fields, a failure response message must be returned indicating,
"Attempt to add a virtual channel connection branch to an existing
virtual path connection." For the VPC Add Branch message, if a
virtual channel connection already exists on any of the virtual
channels within the virtual path specified by the Input Port and
Input VPI fields, a failure response message must be returned
indicating, "Attempt to add a virtual path connection branch to an
existing virtual channel connection."
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields; or the virtual path connection specified
by the Input Port and Input VPI fields; already exists, but the
specified output branch does not, the new output branch must be
added. The new output branch should have the QoS attributes
specified by the Class of Service field.
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields; or the virtual path connection specified
by the Input Port and Input VPI fields; already exists and the
specified output branch also already exists, the QoS attributes of
the connection, specified by the Class of Service field, if different
from the request message, should be changed to that in the request
message. A success response message must be sent if the Result field
of the request message is "AckAll". This allows the controller to
periodically reassert the state of a connection or to change its
priority. If the result field of the request message is
"NoSuccessAck" a success response message should not be returned.
This may be used to reduce the traffic on the control link for
messages that are reasserting previously established state. For
messages that are reasserting previously established state, the
switch must always check that this state is correctly established in
the switch hardware (i.e. the actual connection tables used to
forward cells).
If the output branch specified by the Output Port, Output VPI, and
Output VCI fields for a virtual channel connection; or the output
branch specified by the Output Port and Output VPI fields for a
virtual path connection; is already in use by any connection other
than that specified by the Input Port, Input VPI, and Input VCI
fields, then the resulting output branch will have multiple input
branches. If multiple point-to-point connections share the same
output branch the result will be a multipoint-to-point connection. If
multiple point-to-multipoint trees share the same output branches the
result will be a multipoint-to-multipoint connection.
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields, or the virtual path connection specified
by the Input Port and Input VPI fields, already exists, and the
Bidirectional Flag in the Flags field is set, a failure response must
be returned indicating: "Only point-to-point bidirectional
connections may be established."
It should be noted that different switches support multicast in
different ways. There will be a limit to the total number of point-
to-multipoint connections any switch can support, and possibly a
limit on the maximum number of branches that a point-to-multipoint
connection may specify. Some switches also impose a limit on the
number of different VPI/VCI values that may be assigned to the output
branches of a point-to-multipoint connection. Many switches are
incapable of supporting more than a single branch of any particular
point-to-multipoint connection on the same output port. Specific
failure codes are defined for some of these conditions.
4.2 Delete Tree Message
The Delete Tree message is a connection management message used to
delete an entire virtual channel connection or an entire virtual path
connection. All remaining branches of the connection are deleted. A
virtual channel connection is specified by the Input Port, Input VPI,
and Input VCI fields. A virtual path connection is specified by the
Input Port and Input VPI fields. The Output Port, Output VPI, and
Output VCI fields are not used in this message. The Delete Tree
message is:
Message Type = 18
If the Result field of the request message is "AckAll" a success
response message must be sent upon successful deletion of the
specified connection. The success message must not be sent until the
delete operation has been completed and if possible, not until all
data on the connection, queued for transmission, has been
transmitted. The Number of Branches field is not used in either the
request or response messages of the Delete Tree message.
4.3 Verify Tree Message
The Verify Tree message has been removed from this version of GSMP.
Its function has been replaced by the Number of Branches field in the
success response to the Add Branch message which contains the number
of branches on a virtual channel connection after successful
completion of an add branch operation.
Message Type = 19 is reserved.
If a request message is received with Message Type = 19 a failure
response must be returned with the Code field indicating: "The
specified request is not implemented in this version of the
protocol."
4.4 Delete All Message
The Delete All message is a connection management message used to
delete all connections on a switch input port. All connections that
arrive at the specified input port must be deleted. On completion of
the operation all dynamically assigned VPI/VCI values for the
specified port must be unassigned, i.e. there must be no virtual
connections established in the VPI/VCI space that GSMP controls on
this port. The Input VPI, Input VCI, Output Port, Output VPI, and
Output VCI fields are not used in this message. The Delete All
message is:
Message Type = 20
If the Result field of the request message is "AckAll" a success
response message must be sent upon completion of the operation. The
Number of Branches field is not used in either the request or
response messages of the Delete All message. The success response
message must not be sent until the operation has been completed.
The following failure response messages may be returned to a Delete
All request.
The specified request is not implemented on this switch.
One or more of the specified ports does not exist.
Invalid Port Session Number.
If any field in a Delete All message not covered by the above failure
codes is invalid, a failure response must be returned indicating:
"Invalid request message." Else, the delete all operation must be
completed successfully and a success message returned. No other
failure messages are permitted.
4.5 Delete Branches Message
The Delete Branches message is a connection management message used
to request one or more delete branch operations. Each delete branch
operation deletes a branch of a virtual channel connection or a
virtual path connection, or in the case of the last branch of a
connection, it deletes the connection. The Delete Branches message
is:
Message Type = 17
The request message has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Number of Elements |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Delete Branch Elements ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Number of Elements
Specifies the number of Delete Branch Elements to follow in
the message. The number of Delete Branch Elements in a
Delete Branches message must not cause the packet length to
exceed the maximum transmission unit defined by the
encapsulation.
Each Delete Branch Element specifies an output branch to be deleted
and has the following structure:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error | Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| Output VPI | Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Error
Is used to return a failure code indicating the reason for
the failure of a specific Delete Branch Element in a Delete
Branches failure response message. The Error field is not
used in the request message and must be set to zero. A
value of zero is used to indicate that the delete operation
specified by this Delete Branch Element was successful.
Values for the other failure codes are specified in Section
3.2, "Failure Response Messages."
All other fields of the Delete Branch Element have the same
definition as specified for the other connection management
messages.
In each Delete Branch Element, either a virtual channel connection is
specified by the Input Port, Input VPI, and Input VCI fields; or a
virtual path connection is specified by the Input Port and Input VPI
fields. The specific branch to be deleted is indicated by the Output
Port, Output VPI, and Output VCI fields for virtual channel
connections and by the Output Port and Output VPI for virtual path
connections.
If the Result field of the Delete Branches request message is
"AckAll" a success response message must be sent upon successful
deletion of the branches specified by all of the Delete Branch
Elements. The success response message must not be sent until all of
the delete branch operations have been completed. The success
response message is only sent if all of the requested delete branch
operations were successful. No Delete Branch Elements are returned in
a Delete Branches success response message and the Number of Elements
field must be set to zero.
If there is a failure in any of the Delete Branch Elements a Delete
Branches failure response message must be returned. The Delete
Branches failure response message is a copy of the request message
with the Code field of the entire message set to, "Failure specific
to the particular message type," and the Error field of each Delete
Branch Element indicating the result of each requested delete
operation. A failure in any of the Delete Branch Elements must not
interfere with the processing of any other Delete Branch Elements.
4.6 Move Branch Message
The Move Branch message is used to move a branch of an existing
connection from its current output port VPI/VCI to a new output port
VPI/VCI in a single atomic transaction. This operation occurs
frequently in IP switching, every time a flow is switched from hop-
by-hop forwarding to a dedicated virtual channel. The Move Branch
connection management message has the following format for both
request and response messages:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Old Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| Old Output VPI | Old Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| New Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|x x x x| New Output VPI | New Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Branches | Class of Service |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The VCC Move Branch message is a connection management message used
to move a single output branch of a virtual channel connection from
its current output port, output VPI, and output VCI, to a new output
port, output VPI, and output VCI on the same virtual channel
connection. None of the other output branches are modified. When the
operation is complete the original output VPI/VCI on the original
output port will be deleted from the connection. The VCC Move Branch
message is:
Message Type = 22
For the VCC Move Branch message, if the virtual channel connection
specified by the Input Port, Input VPI, and Input VCI fields already
exists, and the output branch specified by the Old Output Port, Old
Output VPI, and Old Output VCI fields exists as a branch on that
connection, the output branch specified by the New Output Port, New
Output VPI, and New Output VCI fields is added to the connection and
the branch specified by the Old Output Port, Old Output VPI, and Old
Output VCI fields is deleted. If the Result field of the request
message is "AckAll" a success response message must be sent upon
successful completion of the operation. The success response message
must not be sent until the Move Branch operation has been completed.
For the VCC Move Branch message, if the virtual channel connection
specified by the Input Port, Input VPI, and Input VCI fields already
exists, but the output branch specified by the Old Output Port, Old
Output VPI, and Old Output VCI fields does not exist as a branch on
that connection, a failure response must be returned with the Code
field indicating, "The specified branch does not exist."
The VPC Move Branch message is a connection management message used
to move a single output branch of a virtual path connection from its
current output port and output VPI, to a new output port and output
VPI on the same virtual channel connection. None of the other output
branches are modified. When the operation is complete the original
output VPI on the original output port will be deleted from the
connection. The VPC Move Branch message is:
Message Type = 27
For the VPC Move Branch message, if the virtual path connection
specified by the Input Port and Input VPI fields already exists, and
the output branch specified by the Old Output Port and Old Output VPI
fields exists as a branch on that connection, the output branch
specified by the New Output Port and New Output VPI fields is added
to the connection and the branch specified by the Old Output Port and
Old Output VPI fields is deleted. If the Result field of the request
message is "AckAll" a success response message must be sent upon
successful completion of the operation. The success response message
must not be sent until the Move Branch operation has been completed.
For the VPC Move Branch message, if the virtual path connection
specified by the Input Port and Input VPI fields already exists, but
the output branch specified by the Old Output Port and Old Output VPI
fields does not exist as a branch on that connection, a failure
response must be returned with the Code field indicating, "The
specified branch does not exist."
If the virtual channel connection specified by the Input Port, Input
VPI, and Input VCI fields; or the virtual path connection specified
by the Input Port and Input VPI fields; does not exist, a failure
response must be returned with the Code field indicating, "The
specified connection does not exist."
If the output branch specified by the New Output Port, New Output
VPI, and New Output VCI fields for a virtual channel connection; or
the output branch specified by the New Output Port and New Output VPI
fields for a virtual path connection; is already in use by any
connection other than that specified by the Input Port, Input VPI,
and Input VCI fields then the resulting output branch will have
multiple input branches. If multiple point-to-point connections share
the same output branch the result will be a multipoint-to-point
connection. If multiple point-to-multipoint trees share the same
output branches the result will be a multipoint-to-multipoint
connection.
5. Port Management Messages
5.1 Port Management Message
The Port Management message allows a port to be brought into service,
taken out of service, looped back, reset, or the transmit cell rate
changed. Only the Bring Up and the Reset Input Port functions change
the connection state (established connections) on the input port.
Only the Bring Up function changes the value of the Port Session
Number. If the Result field of the request message is "AckAll" a
success response message must be sent upon successful completion of
the operation. The success response message must not be sent until
the operation has been completed. The Port Management Message is:
Message Type = 32
The Port Management message has the following format for the request
and success response messages:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Event Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Event Flags | Duration | Function |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Event Sequence Number
In the success response message gives the current value of
the Event Sequence Number of the switch port indicated by
the Port field. The Event Sequence Number is set to zero
when the port is initialized. It is incremented by one each
time the port detects an asynchronous event that the switch
would normally report via an Event message. If the Event
Sequence Number in the success response differs from the
Event Sequence Number of the most recent Event message
received for that port, events have occurred that were not
reported via an Event message. This is most likely to be
due to the flow control that restricts the rate at which a
switch can send Event messages for each port. In the
request message this field is not used.
Event Flags
Field in the request message is used to reset the Event
Flags in the switch port indicated by the Port field. Each
Event Flag in a switch port corresponds to a type of Event
message. When a switch port sends an Event message it sets
the corresponding Event Flag on that port. The port is not
permitted to send another Event message of the same type
until the Event Flag has been reset. If the Function field
in the request message is set to "Reset Event Flags," for
each bit that is set in the Event Flags field, the
corresponding Event Flag in the switch port is reset.
The Event Flags field is only used in a request message
with the Function field set to "Reset Event Flags." For all
other values of the Function field, the Event Flags field
is not used. In the success response message the Event
Flags field must be set to the current value of the Event
Flags for the port, after the completion of the operation
specified by the request message, for all values of the
Function field. Setting the Event Flags field to all zeros
in a "Reset Event Flags" request message allows the
controller to obtain the current state of the Event Flags
and the current Event Sequence Number of the port without
changing the state of the Event Flags.
The correspondence between the types of Event message and
the bits of the Event Flags field is as follows:
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|U|D|I|N|Z|x x x|
+-+-+-+-+-+-+-+-+
U: Port Up Bit 0, (most significant bit)
D: Port Down Bit 1,
I: Invalid VPI/VCI Bit 2,
N: New Port Bit 3,
Z: Dead Port Bit 4,
x: Unused Bits 5--7.
Duration
Is the length of time, in seconds, that any of the loopback
states remain in operation. When the duration has expired
the port will automatically be returned to service. If
another Port Management message is received for the same
port before the duration has expired, the loopback will
continue to remain in operation for the length of time
specified by the Duration field in the new message. The
Duration field is only used in request messages with the
Function field set to Internal Loopback, External Loopback,
or Bothway Loopback.
Function
Specifies the action to be taken. The specified action will
be taken regardless of the current status of the port
(Available, Unavailable, or any Loopback state). If the
specified function requires a new Port Session Number to be
generated, the new Port Session Number must be returned in
the success response message. The defined values of the
Function field are:
Bring Up:
Function = 1. Bring the port into service. All
connections that arrive at the specified input port
must be deleted and a new Port Session Number must be
selected using some form of random number. On
completion of the operation all dynamically assigned
VPI/VCI values for the specified input port must be
unassigned, i.e. no virtual connections will be
established in the VPI/VCI space that GSMP controls on
this input port. The Port Status of the port
afterwards will be Available.
Take Down:
Function = 2. Take the port out of service. Any cells
received at this port will be discarded. No cells will
be transmitted from this port. The Port Status of the
port afterwards will be Unavailable.
The behavior is undefined if the port is taken down
over which the GSMP session that controls the switch
is running. (In this case the most probable behavior
would be for the switch either to ignore the message
or to terminate the current GSMP session and to
initiate another session, possibly with the backup
controller, if any.) The correct method to reset the
link over which GSMP is running is to issue an RSTACK
message in the adjacency protocol.
Internal Loopback:
Function = 3. Cells arriving at the output port from
the switch fabric are looped through to the input port
to return to the switch fabric. All of the ATM
functions of the input port above the physical layer,
e.g. header translation, are performed upon the looped
back cells. The Port Status of the port afterwards
will be Internal Loopback.
External Loopback:
Function = 4. Cells arriving at the input port from
the external communications link are immediately
looped back to the communications link at the physical
layer without entering the input port. None of the ATM
functions of the input port above the physical layer
are performed upon the looped back cells. The Port
Status of the port afterwards will be External
Loopback.
Bothway Loopback:
Function = 5. Both internal and external loopback are
performed. The Port Status of the port afterwards will
be Bothway Loopback.
Reset Input Port:
Function = 6. All connections that arrive at the
specified input port must be deleted and the input and
output port hardware re-initialized. On completion of
the operation all dynamically assigned VPI/VCI values
for the specified input port must be unassigned, i.e.
no virtual connections will be established in the
VPI/VCI space that GSMP controls on this input port.
The range of VPIs and VCIs that may be controlled by
GSMP on this port will be set to the default values
specified in the Port Configuration message. The
transmit cell rate of the output port must be set to
its default value. The Port Session Number is not
changed by the Reset Input Port function. The Port
Status of the port afterwards will be Unavailable.
Reset Event Flags:
Function = 7. For each bit that is set in the Event
Flags field, the corresponding Event Flag in the
switch port must be reset. The Port Status of the port
is not changed by this function.
Set Transmit Cell Rate:
Function = 8. Sets the transmit cell rate of the
output port as close as possible to the rate specified
in the Transmit Cell Rate field. In the success
response message the Transmit Cell Rate must indicate
the actual transmit cell rate of the output port. If
the transmit cell rate of the requested output port
cannot be changed, a failure response must be returned
with the Code field indicating: "The transmit cell
rate of this output port cannot be changed." If the
transmit cell rate of the requested output port can be
changed, but the value of the Transmit Cell Rate field
is beyond the range of acceptable values, a failure
response must be returned with the Code field
indicating: "Requested transmit cell rate out of range
for this output port." In the failure response message
the Transmit Cell Rate must contain the same value as
contained in the request message that caused the
failure. The transmit cell rate of the output port is
not changed by the Bring Up, Take Down, or any of the
Loopback functions. It is returned to the default
value by the Reset Input Port function.
Transmit Cell Rate
This field is only used in request and success response
messages with the Function field set to "Set Transmit Cell
Rate." It is used to set the output cell rate of the output
port. It is specified in cells/s. If the Transmit Cell Rate
field contains the value 0xFFFFFFFF the transmit cell rate
of the output port should be set to the highest valid
value.
5.2. Label Range Message
The default label range, Min VPI to Max VPI and Min VCI to Max VCI,
is specified for each port by the Port Configuration or the All Ports
Configuration messages. When the protocol is initialized, before the
transmission of any Label Range messages, the label range of each
port will be set to the default label range. (The default label range
is dependent upon the switch design and configuration and is not
specified by the GSMP protocol.) The Label Range message allows the
range of VPIs supported by a specified port, or the range of VCIs
supported by a specified VPI on a specified port, to be changed.
Each switch port must declare whether it supports the Label Range
message in the Port Configuration or the All Ports Configuration
messages. The Label Range message is:
Message Type = 33
The Label Range message has the following format for the request and
success response messages:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Q|V|x x| Min VPI |x x x x| Max VPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min VCI | Max VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remaining VPIs | Remaining VCIs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags
Q: Query
If the Query flag is set in a request message, the switch
must respond with the current range of valid VPIs, or the
current range of valid VCIs on a specified VPI, according
to the VPI/VCI flag. The current label range is not changed
by a request message with the Query flag set. If the Query
flag is zero, the message is requesting a label change
operation.
V: VPI/VCI
If the VPI/VCI flag is set, the message refers to a range
of VPIs only. The Min VCI and Max VCI fields are unused. If
the VPI/VCI flag is zero the message refers to a range of
VCIs on either one VPI or on a range of VPIs.
x: Unused
Min VPI
Max VPI
Specify a range of VPI values, Min VPI to Max VPI
inclusive. A single VPI may be specified with a Min VPI
and a Max VPI having the same value. In a request message,
if the value of the Max VPI field is less than or equal to
the value of the Min VPI field, the requested range is a
single VPI with a value equal to the Min VPI field. Zero is
a valid value. In a request message, if the Query flag is
set, and the VPI/VCI flag is zero, the Max VPI field
specifies a single VPI and the Min VPI field is not used.
The maximum valid value of these fields for both request
and response messages is 0xFFF.
Min VCI
Max VCI
Specify a range of VCI values, Min VCI to Max VCI
inclusive. A single VCI may be specified with a Min VCI
and a Max VCI having the same value. In a request message,
if the value of the Max VCI field is less than or equal to
the value of the Min VCI field, the requested range is a
single VCI with a value equal to the Min VCI field. Zero is
a valid value. (However, VPI=0, VCI=0 is not available as
a virtual channel connection as it is used as a special
value in ATM to indicate an unassigned cell.)
Remaining VPIs
Remaining VCIs
These fields are unused in the request message. In the
success response message and in the failure response
message these fields give the maximum number of remaining
VPIs and VCIs that could be requested for allocation on the
specified port (after completion of the requested operation
in the case of the success response). It gives the switch
controller an idea of how many VPIs and VCIs it could
request. The number given is the maximum possible given the
constraints of the switch hardware. There is no implication
that this number of VPIs and VCIs is available to every
switch port.
If the Query flag and the VPI/VCI flag are set in the request
message, the switch must reply with a success response message
containing the current range of valid VPIs that are supported by the
port. The Min VPI and Max VPI fields are not used in the request
message.
If the Query flag is set and the VPI/VCI flag is zero in the request
message, the switch must reply with a success response message
containing the current range of valid VCIs that are supported by the
VPI specified by the Max VPI field. If the requested VPI is invalid,
a failure response must be returned indicating: "One or more of the
specified input VPIs is invalid." The Min VPI field is not used in
either the request or success response messages.
If the Query flag is zero and the VPI/VCI flag is set in the request
message, the Min VPI and Max VPI fields specify the new range of VPIs
to be allocated to the input port specified by the Port field.
Whatever the range of VPIs previously allocated to this port it
should be increased or decreased to the specified value.
If the Query flag and the VPI/VCI flag are zero in the request
message, the Min VCI and Max VCI fields specify the range of VCIs to
be allocated to each of the VPIs specified by the VPI range.
Whatever the range of VCIs previously allocated to each of the VPIs
within the specified VPI range on this port, it should be increased
or decreased to the specified value. The allocated VCI range must be
the same on each of the VPIs within the specified VPI range.
The success response to a Label Range message requesting a change of
label range is a copy of the request message with the Remaining VPIs
and Remaining VCIs fields updated to the new values after the Label
Range operation.
If the switch is unable to satisfy a request to change the VPI range,
it must return a failure response message with the Code field set to
"Cannot support requested VPI range." In this failure response
message the switch must use the Min VPI and Max VPI fields to suggest
a VPI range that it would be able to satisfy.
If the switch is unable to satisfy a request to change the VCI range
on all VPIs within the requested VPI range, it must return a failure
response message with the Code field set to "Cannot support requested
VCI range on all requested VPIs." In this failure response message
the switch must use the Min VPI, Max VPI, Min VCI, and Max VCI fields
to suggest a VPI and VCI range that it would be able to satisfy.
In all other failure response messages for the label range operation
the switch must return the values of Min VPI, Max VPI, Min VCI, and
Max VCI from the request message.
While switches can typically support all 256 or 4096 VPIs the VCI
range that can be supported is often more constrained. Often the Min
VCI must be 0 or 32. Typically all VCIs within a particular VPI must
be contiguous. The hint in the failure response message allows the
switch to suggest a label range that it could satisfy in view of its
particular architecture.
While the Label Range message is defined to specify both a range of
VPIs and a range of VCIs within each VPI, the most likely use is to
change either the VPI range or the range of VCIs within a single VPI.
It is possible for a VPI to be valid but to be allocated no valid
VCIs. Such a VPI could be used for a virtual path connection but to
support virtual channel connections it would need to be allocated a
range of VCIs.
A Label Range request message may be issued regardless of the Port
Status or the Line Status of the target switch port. If the Port
field of the request message contains an invalid port (a port that
does not exist or a port that has been removed from the switch) a
failure response message must be returned with the Code field set to,
"One or more of the specified ports does not exist."
6. State and Statistics Messages
The state and statistics messages permit the controller to request
the values of various hardware counters associated with the switch
input and output ports, virtual path connections, virtual channel
connections, and QoS Classes. They also permit the controller to
request the connection state of a switch input port. The Connection
Activity message is used to determine whether one or more specific
virtual channel connections or virtual path connections have recently
been carrying traffic. The Statistics message is used to query the
various port, connection, and QoS class traffic and error counters.
The Report Connection State message is used to request an input port
to report the connection state for a single virtual channel
connection, a single virtual path connection, or for the entire input
port.
6.1 Connection Activity Message
The Connection Activity message is used to determine whether one or
more specific virtual channel connections or virtual path connections
have recently been carrying traffic. The Connection Activity message
contains one or more Activity Records. Each Activity Record is used
to request and return activity information concerning a single
virtual channel connection or virtual path connection. Each virtual
channel connection is specified by its input port, input VPI, and
input VCI. Each virtual path connection is specified by its input
port and input VPI. These are specified in the Input Port, Input VPI,
and Input VCI fields of each Activity Record. Two forms of activity
detection are supported. If the switch supports per connection
traffic accounting, the current value of the traffic counter for each
specified virtual channel connection or virtual path connection must
be returned. The units of traffic counted are not specified but will
typically be either cells or frames. The controller must compare the
traffic counts returned in the message with previous values for each
of the specified connections to determine whether each connection has
been active in the intervening period. If the switch does not
support per connection traffic accounting, but is capable of
detecting per connection activity by some other unspecified means,
the result may be indicated for each connection using the Flags
field. The Connection Activity message is:
Message Type = 48
The Connection Activity request and success response messages have
the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Number of Records | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Activity Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Number of Records
Field specifies the number of Activity Records to follow.
The number of Connection Activity records in a single
Connection Activity message must not cause the packet
length to exceed the maximum transmission unit defined by
the encapsulation.
Each Activity Record has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|C|A|x| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Traffic Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Identifies the port number of the input port on which the
connection of interest arrives in order to identify the
connection (regardless of whether the traffic count for the
connection is maintained on the input port or the output
port).
Input VPI
Input VCI
Fields identify the specific virtual path connection or
virtual channel connection for which statistics are being
requested. For a virtual path connection the Input VCI
field is not used.
Flags
V: Valid Record
In the success response message the Valid Record flag is
used to indicate an invalid Activity Record. The flag must
be zero if any of the fields in this Activity Record are
invalid, if the input port specified by the Input Port
field does not exist, or if the specified connection does
not exist. If the Valid Record flag is zero in a success
response message, the Counter flag, the Activity flag, and
the VC Traffic Count field are undefined. If the Valid
Record flag is set, the Activity Record is valid, and the
Counter and Activity flags are valid. The Valid Record flag
is not used in the request message.
C: Counter
In a success response message, if the Valid Record flag is
set, the Counter flag, if zero, indicates that the value in
the VC Traffic Count field is valid. If set, it indicates
that the value in the Activity flag is valid. The Counter
flag is not used in the request message.
A: Activity
In a success response message, if the Valid Record and
Counter flags are set, the Activity flag, if set, indicates
that there has been some activity on this connection since
the last Connection Activity message for this connection.
If zero, it indicates that there has been no activity on
this connection since the last Connection Activity message
for this connection. The Activity flag is not used in the
request message.
x: Unused
Traffic Count
Field is not used in the request message. In the success
response message, if the switch supports per connection
traffic counting, the Traffic Count field must be set to
the value of a free running, connection specific, 64-bit
traffic counter counting traffic flowing across the
specified connection. The value of the traffic counter is
not modified by reading it. If per connection traffic
counting is supported, the switch must report the
Connection Activity result using the traffic count rather
than using the Activity flag.
The format of the failure response is the same as the request message
with the Number of Records field set to zero and no VC Activity
records returned in the message. If the switch is incapable of
detecting per connection activity, a failure response must be
returned indicating, "The specified request is not implemented on
this switch."
6.2 Statistics Messages
The Statistics messages are used to query the various port,
connection, and QoS class traffic and error counters.
The Statistics request messages have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QoS Class Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
VPI
VCI
Fields identify the specific virtual path connection or
virtual channel connection for which statistics are being
requested. For a virtual path connection the Input VCI
field is not used. For requests that do not require a
virtual path connection or virtual channel connection to be
specified, the VPI and VCI fields are not used.
QoS Class Identifier
Field identifies the QoS class for which statistics are
being requested. This field is only used if the QoS Class
Establishment message defined in section 9.4 is
implemented.
The success response for the Statistics message has the following
format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| QoS Class Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Cell Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Frame Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Cell Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Frame Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input HEC Error Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Input Invalid VPI/VCI Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Cell Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Frame Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Cell Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Output Frame Discard Count +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Port
VPI/VCI
QoS Class Identifier
Fields are the same as those of the request message.
Input Cell Count
Output Cell Count
Give the value of a free running 64-bit counter counting
cells arriving at the input or departing from the output
respectively.
Input Frame Count
Output Frame Count
Give the value of a free running 64-bit counter counting
frames (packets) arriving at the input or departing from
the output respectively.
Input Cell Discard Count
Output Cell Discard Count
Give the value of a free running 64-bit counter counting
cells discarded due to queue overflow on an input port or
on an output port respectively.
Input Frame Discard Count
Output Frame Discard Count
Give the value of a free running 64-bit counter counting
frames discarded due to congestion on an input port or on
an output port respectively.
HEC Error Count
Gives the value of a free running 64-bit counter counting
cells discarded due to header checksum errors on arrival at
an input port.
Invalid VPI/VCI Count
Gives the value of a free running 64-bit counter counting
cells discarded because their VPI/VCI is invalid on arrival
at an input port. For a virtual channel connection an
incoming VPI/VCI is invalid if no connection is currently
established having that value of VPI/VCI. For a virtual
path connection an incoming VPI is invalid if no connection
is currently established having that value of VPI.
6.2.1 Port Statistics Message
The Port Statistics message requests the statistics for the switch
port specified in the Port field. The contents of the VPI/VCI and the
QoS Class Identifier fields in the Port Statistics request message
are ignored. All of the count fields in the success response message
refer to per-port counts regardless of the connection or QoS class to
which the cells belong. Any of the count fields in the success
response message not supported by the port must be set to zero. The
Port Statistics message is:
Message Type = 49
6.2.2 Connection Statistics Message
The Connection Statistics message requests the statistics for the
virtual channel connection specified in the VPI/VCI field, or the
virtual path connection specified in the VPI field, that arrives on
the switch input port specified in the Port field, regardless of the
QoS class to which the cells belong. All of the count fields in the
success response message refer only to the specified connection. The
HEC Error Count and Invalid VPI/VCI Count fields are not connection
specific and must be set to zero. Any of the other count fields not
supported on a per connection basis must be set to zero in the
success response message. The Connection Statistics message is:
Message Type = 50
6.2.3 QoS Class Statistics Message
The QoS Class Statistics message requests the statistics for the QoS
class specified by the QoS Class Identifier field that arrives on the
switch input port specified in the Port field, regardless of the
connection to which the cells belong. The QoS Statistics message is
only used if the QoS Class Establishment message defined in section
9.4 is implemented. The contents of the VPI/VCI fields in the QoS
Class Statistics request message are ignored. All of the count fields
in the success response message refer only to the specified QoS
class. The HEC Error Count and Invalid VPI/VCI Count fields are not
specific to a QoS class and must be set to zero. Any of the other
count fields not supported on a per QoS class basis must be set to
zero in the success response message. The QoS Class Statistics
message is:
Message Type = 51
6.3 Report Connection State Message
The Report Connection State message is used to request an input port
to report the connection state for a single virtual channel
connection, a single virtual path connection, or for the entire input
port. The Report Connection State message is:
Message Type = 52
The Report Connection State request message has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|V|x x| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Identifies the port number of the input port for which the
connection state is being requested.
Flags
A: All Connections
If the All Connections flag is set, the message requests
the connection state for all virtual path connections and
virtual channel connections that arrive at the input port
specified by the Input Port field. In this case the Input
VPI and Input VCI fields and the VPI/VCI flag are unused.
V: VPI/VCI
If the All Connections flag is zero and the VPI/VCI flag is
set, the message requests the connection state for the
virtual path connection that arrives at the input port
specified by the Input Port and Input VPI fields. If the
specified Input VPI identifies a virtual path connection
(i.e. a single switched virtual path) the state for that
connection is requested. If the specified Input VPI
identifies a virtual path containing virtual channel
connections, the message requests the connection state for
all virtual channel connections that belong to the
specified virtual path. The Input VCI field is not used.
If the All Connections flag is zero and the VPI/VCI flag is
also zero, the message requests the connection state for
the virtual channel connection that arrives at the input
port specified by the Port, Input VPI and Input VCI fields.
x: Unused.
Input VPI
Input VCI
Fields identify the specific virtual path connection, the
specific virtual path, or the specific virtual channel
connection for which connection state is being requested.
For a virtual path connection (switched as a single virtual
path connection) or a virtual path (switched as one or more
virtual channel connections within the virtual path) the
Input VCI field is not used. For requests that do not
require a virtual path connection or virtual channel
connection to be specified, the Input VPI and Input VCI
fields are not used.
The Report Connection State success response message has the
following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Input Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Connection Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Input Port
Is the same as the Input Port field in the request message.
It identifies the port number of the input port for which
the connection state is being reported.
Sequence Number
In the case that the requested connection state cannot be
reported in a single success response message, each
successive success response message in reply to the same
request message must increment the Sequence Number. The
Sequence Number of the first success response message, in
response to a new request message, must be zero.
Connection Records
Each success response message must contain one or more
Connection Records. Each Connection Record specifies a
single point-to-point or point-to-multipoint virtual path
connection or virtual channel connection. The number of
Connection Records in a single Report Connection State
success response must not cause the packet length to exceed
the maximum transmission unit defined by the encapsulation.
If the requested connection state cannot be reported in a
single success response message, multiple success response
messages must be sent. All success response messages that
are sent in response to the same request message must have
the same Input Port and Transaction Identifier fields as
the request message. A single Connection Record must not be
split across multiple success response messages. The More
flag of the last Connection Record in a success response
message indicates whether the response to the request has
been completed or whether one or more further success
response messages should be expected in response to the
same request message.
Each Connection Record has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|A|V|P|M| Input VPI | Input VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Output Branch Records ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Flags
A: All Connections
V: VPI/VCI
For the first Connection Record in each success response
message the All Connections and the VPI/VCI flags must be
the same as those of the request message. For successive
Connection Records in the same success response message
these flags are not used.
P: VPC
The VPC flag, if set, indicates that the Connection Record
refers to a virtual path connection. If zero, it indicates
that the Connection Record refers to a virtual channel
connection.
M: More
If the More flag is set, it indicates that another
Connection Record, in response to the same request message,
will follow either in the same success response message or
in a successive success response message. If the More flag
is zero it indicates that this is the last Connection
record in this success response message and that no further
success response messages will be sent in response to the
current request message. It indicates that the response to
the request message is now complete.
Input VPI
Input VCI
The input VPI and VCI of the connection specified in this
Connection Record. If this Connection Record specifies a
virtual path connection (the VPC flag is set) the Input VCI
field is unused.
Output Branch Records
Each Connection Record must contain one or more Output
Branch Records. Each Output Branch Record specifies a
single output branch belonging to the connection identified
by the Input VPI and Input VCI fields of the Connection
Record. A point-to-point connection will require only a
single Output Branch Record. A point-to-multipoint
connection will require multiple Output Branch Records. The
last Output Branch Record of each Connection Record is
indicated by the Last Branch flag of the Output Branch
Record. If a point-to-multipoint connection has more output
branches than can fit in a single Connection Record
contained within a single success response message, that
connection may be reported using multiple Connection
Records in multiple success response messages.
Each Output Branch Record has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Output Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|L|x x x| Output VPI | Output VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Output Port
The output port of the switch to which this output branch
is routed.
Flags
L: Last Branch
The Last Branch flag, if set, indicates that this is the
last Output Branch Record of this Connection Record. If
zero, it indicates that one or more further Output Branch
Records are to follow. If this is the last Output Branch
Record in the message and the Last Branch flag is zero,
further output branches belonging to the same connection
will be given in another Connection Record. This Connection
Record will be the first Connection Record in the next
success response message. This Connection Record must have
the same Input VPI and Input VCI values as the current
Connection Record.
x: Unused.
Output VPI
Output VCI
The output VPI and VCI of the output branch specified in
this Output Branch Record. If this Output Branch Record is
part of a Connection Record that specifies a virtual path
connection (the VPC flag is set) the Output VCI field is
unused.
A Report Connection State request message may be issued regardless of
the Port Status or the Line Status of the target switch port.
If the Input Port of the request message is valid, and the All
Connections flag is set, but there are no connections established on
that port, a failure response message must be returned with the code
field set to, "Failure specific to the particular message type." For
the Report Connection State message, this failure code indicates that
no connections matching the request message were found. This failure
message should also be returned if the Input Port of the request
message is valid, the All Connections flag is zero, and no
connections are found on that port matching the specified virtual
path connection, virtual path, or virtual channel connection.
7. Configuration Messages
The configuration messages permit the controller to discover the
capabilities of the switch. Three configuration request messages have
been defined: Switch, Port, and All Ports.
All configuration request messages have the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
7.1 Switch Configuration Message
The Switch Configuration message requests the global (non port-
specific) configuration for the switch. The Switch Configuration
message is:
Message Type = 64
The Port field is not used in the request message.
The Switch Configuration success response message has the following
format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Firmware Version Number | Window Size |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switch Type | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| Switch Name |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Firmware Version Number
The version number of the switch control firmware
installed.
Window Size
The maximum number of unacknowledged request messages that
may be transmitted by the controller without the
possibility of loss. This field is used to prevent request
messages being lost in the switch because of overflow in
the receive buffer. The field is a hint to the controller.
If desired, the controller may experiment with higher and
lower window sizes to determine heuristically the best
window size.
Switch Type
A 16-bit field allocated by the manufacturer of the switch.
(For these purposes the manufacturer of the switch is
assumed to be the organization identified by the OUI in the
Switch Name field.) The Switch Type identifies the product.
When the Switch Type is combined with the OUI from the
Switch Name the product is uniquely identified. Network
Management may use this identification to obtain product
related information from a database.
Switch Name
A 48-bit quantity that is unique within the operational
context of the device. A 48-bit IEEE 802 MAC address, if
available, may be used as the Switch Name. The most
significant 24 bits of the Switch Name must be an
Organizationally Unique Identifier (OUI) that identifies
the manufacturer of the switch.
7.2 Port Configuration Message
The Port Configuration message requests the switch for the
configuration information of a single switch port. The Port field in
the request message specifies the port for which the configuration is
requested. The Port Configuration message is:
Message Type = 65.
The Port Configuration success response message has the following
format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Message Type | Result | Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transaction Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Session Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V|M|L|R| Min VPI |Q|x x x| Max VPI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Min VCI | Max VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transmit Cell Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Port Status | Port Type | Line Status | Priorit