Patent application number | Description | Published |
20100061252 | Reducing CC Message Transmission in a Provider Network - A method and apparatus for reducing the number of CC messages transmitted in a provider network. In one embodiment of the invention, a first service provider network element receives CC messages from a first customer network at a first periodicity rate. The first service provider network element stores the received CC messages and reduces the first periodicity rate to create a second periodicity rate that is smaller than the first periodicity rate. The first service provider network element transmits CC messages to a second service provider network element through the provider network at the second periodicity rate. Other methods and apparatus are also described. | 03-11-2010 |
20100165832 | HVPLS Hub Connectivity Failure Recovery With Dynamic Spoke Pseudowires - Techniques for recovering from hierarchical virtual private LAN service (HVPLS) hub connectivity failure with a dynamic spoke pseudowire. According to one embodiment of the invention, a provider edge (PE) network element in the HVPLS hub monitors for a failure of HVPLS hub connectivity failure and reuses an HVPLS spoke connectivity failure recovery mechanism in an MTU by fabricating failure of one or more spoke facing connectivity elements coupling the MTU with the PE network element causing the MTU to transition to a secondary PE network element in the HVPLS hub. In addition, the PE network element establishes a dynamic spoke pseudowire for each virtual instance affected with the MTU to restore HVPLS hub connectivity for that PE network element. | 07-01-2010 |
20100226382 | LDP IGP Synchronization for Broadcast Networks - A network element that has a broadcast interface to a broadcast network becoming operational determines whether at least one alternate path exists to the broadcast network. The broadcast interface is to carry traffic on a label switched path. If an alternate path exists, the broadcast interface will not be advertised to the broadcast network until label distribution protocol (LDP) is operational with all neighbors on the broadcast interface. | 09-09-2010 |
20100271980 | Pay-As-You-Grow Gradual Cutover Method To Scale A Provider Bridge Network To A VPLS Or Provider Backbone Bridging Network - A method and apparatus that operates two bridging protocols in a hybrid bridging node is described. The operation of the two bridging protocols in the hybrid node allows for an incremental transition of a provider bridging network from operating a legacy bridging protocol that shares MAC addresses to a bridging network that operates VPLS and/or PBB bridging protocols. The hybrid bridging node selectively broadcasts unicast packets with unknown MAC addresses from the nodes operating VPLS and/or PBB to nodes operating a legacy bridging protocol. | 10-28-2010 |
20100272111 | Address Resolution Optimization Procedure To Effect A Gradual Cutover From A Provider Bridge Network To A VPLS or Provider Backbone Bridging Network - A method and apparatus that operates two bridging protocols in a hybrid bridging node is described. The operation of the two bridging protocols in the hybrid node allows for an incremental transition of a provider bridging network from operating a legacy bridging protocol that shares MAC addresses to a bridging network that operates VPLS and/or PBB bridging protocols. The hybrid bridging node selectively broadcasts address resolution packets and unicast packets with unknown MAC addresses from the nodes operating VPLS and/or PBB to nodes operating a legacy bridging protocol. | 10-28-2010 |
20110044348 | LDP IGP SYNCHRONIZATION FOR BROADCAST NETWORKS - A method and apparatus for LDP-IGP synchronization for broadcast networks. In one embodiment of the invention, responsive to a network element bringing up an adjacency with a Designated Router of the broadcast network on a broadcast interface, that network element advertises in its Link State Advertisement (LSA) a peer-to-peer (P2P) adjacency to each member of the broadcast network that has bidirectional IGP communication with the network element instead of advertising a pseudo-node adjacency to the pseudo-node of the broadcast network. Each P2P adjacency includes a high cost to discourage use of those links for transit traffic. After LDP becomes operational with all neighbors on the broadcast interface, the network element advertises the pseudo-node adjacency instead of the P2P adjacencies. Accordingly, transit traffic is avoided through that network element until LDP is operational with all neighbors on the broadcast interface. | 02-24-2011 |
20110090786 | RSVP-TE GRACEFUL RESTART UNDER FAST RE-ROUTE CONDITIONS - According to one embodiment, in response to at least one of a link failure and node failure of a protected label switched path (LSP), network traffic is switched onto a protection path according to a fast re-reroute (FRR) scheme. A HELLO session is established with the remote node that is not immediately adjacent to the network element, including exchanging one or more HELLO messages with the remote node, each HELLO message having a time-to-live (TTL) value of greater than one if IP forwarding is used. The TTL value of the HELLO message is set to one if the HELLO message is sent via tunnel. In response to a request to restart, a resource reservation protocol (RSVP) traffic engineering (TE) graceful restart (GR) procedure is performed using information obtained from the one or more HELLO messages exchanged with the remote node during the HELLO session. | 04-21-2011 |
20110110226 | Disjoint Path Computation Algorithm - A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP. | 05-12-2011 |
20110194559 | ADDRESS RESOLUTION OPTIMIZATION PROCEDURE TO EFFECT A GRADUAL CUTOVER FROM A PROVIDER BRIDGE NETWORK TO A VPLS OR PROVIDER BACKBONE BRIDGING NETWORK - A method and apparatus that operates two bridging protocols in a hybrid bridging node is described. The operation of the two bridging protocols in the hybrid node allows for an incremental transition of a provider bridging network from operating a legacy bridging protocol that shares MAC addresses to a bridging network that operates VPLS and/or PBB bridging protocols. The hybrid bridging node selectively broadcasts address resolution packets and unicast packets with unknown MAC addresses from the nodes operating VPLS and/or PBB to nodes operating a legacy bridging protocol. | 08-11-2011 |
20110205885 | Optimized Fast Re-Route In MPLS Ring Topologies - A method performed on a network element employing Multi-protocol Label Switching (MPLS) to optimize bandwidth in a ring topology network including a back-up Label Switch Path (LSP) for a protected LSP by re-routing traffic onto the back-up LSP to avoid shared links between the protected LSP and back-up LSP, including receiving a first labeled packet from another label switch router (LSR) in the back-up LSP, the first labeled packet indicating that a protection switch of data is to be performed from the protected LSP to the back-up LSP, determining whether a shared link in the ring topology network exists between the protected LSP and the back-up LSP, rerouting traffic for the protected LSP onto an optimized back-up LSP to remove the shared link, receiving a second labeled packet indicating that a protection switch of data is to be performed, and restoring routing of the traffic onto the protected LSP in response to receiving the second labeled packet. | 08-25-2011 |
20110205907 | Fast LSP Alert Mechanism - A method performed on a network element employing Multiprotocol Label Switching (MPLS) to promulgate an alert to each Label Switch Router (LSR) along a Label Switch Path (LSP) by forwarding a labeled packet serving as an alert packet generated by an LSR in the LSP, the method including receiving the labeled packet by the network element from another LSR in the LSP, determining whether the labeled packet is the alert packet by checking a time to live value in an MPLS label header of the labeled packet, determining whether the labeled packet is an operation, administration and maintenance (OAM) packet based on a presence of a generic associated channel label, copying the labeled packet including a label stack of the labeled packet and forwarding the labeled packet to a next LSR in the LSP, whereby the latency in promulgating the alert to each of the LSRs in the LSP is reduced. | 08-25-2011 |
20110249567 | INTER-WORKING OF EFM-OAM AND CFM-OAM FOR MOBILE BACKHAUL NETWORKS - On a first network element in a radio access network (RAN), supporting operations, management and administration (OAM) between network elements that support Ethernet in the first mile (EFM) and network elements that support connectivity fault management (CFM) in the radio access network by receiving an EFM message from a second network element that supports EFM, wherein the second network element is in the RAN and wherein the EFM message includes OAM data; converting the OAM data from the EFM message into a sub-type-length-value (sub-TLV) of a CFM message; and transmitting the CFM message including the OAM data in the sub-TLV to a third network element that supports CFM, wherein the third network element is in the RAN, whereby an end-to-end OAM sublayer is provided in the RAN by conversion of OAM data from EFM to CFM. | 10-13-2011 |
20110249677 | PAY-AS-YOU-GROW GRADUAL CUTOVER METHOD TO SCALE A PROVIDER BRIDGE NETWORK TO A VPLS OR PROVIDER BACKBONE BRIDGING NETWORK - A method and apparatus that operates two bridging protocols in a hybrid bridging node is described. The operation of the two bridging protocols in the hybrid node allows for an incremental transition of a provider bridging network from operating a legacy bridging protocol that shares MAC addresses to a bridging network that operates VPLS and/or PBB bridging protocols. The hybrid bridging node selectively broadcasts unicast packets with unknown MAC addresses from the nodes operating VPLS and/or PBB to nodes operating a legacy bridging protocol. | 10-13-2011 |
20110261812 | EFFICIENT ENCAPSULATION OF PACKETS TRANSMITTED ON A PACKET-PSEUDOWIRE OVER A PACKET SWITCHED NETWORK - Improving efficiency of encapsulation for packets of a first set of one or more protocols on a packet-pseudowire over a tunnel in a Packet Switched Network (PSN) is described. A first provider edge (PE) network element is coupled with a customer edge (CE) network element over an attachment circuit and is coupled with a second PE network element over the packet-pseudowire. The first provider edge network element receives a frame from the CE network element over the attachment circuit. Responsive to the first PE network element determining that the frame encapsulates a packet of the first set of protocols, the first PE network element encapsulates the packet into a protocol data unit for transmission over the packet-pseudowire without including substantially all of the plurality of fields of the data link layer header. The first PE network element transmits the protocol data unit over the packet-pseudowire over the PSN tunnel to the second PE network element. Efficiency is improved through a reduction of overhead on the packet-pseudowire by removing substantially all the fields of the data link layer header of the first frame. | 10-27-2011 |
20110310730 | HVPLS HUB CONNECTIVITY FAILURE RECOVERY WITH DYNAMIC SPOKE PSEUDOWIRES - Techniques for recovering from hierarchical virtual private LAN service (HVPLS) hub connectivity failure with a dynamic spoke pseudowire. According to one embodiment of the invention, a provider edge (PE) network element in the HVPLS hub monitors for a failure of HVPLS hub connectivity failure and reuses an HVPLS spoke connectivity failure recovery mechanism in an MTU by fabricating failure of one or more spoke facing connectivity elements coupling the MTU with the PE network element causing the MTU to transition to a secondary PE network element in the HVPLS hub. In addition, the PE network element establishes a dynamic spoke pseudowire for each virtual instance affected with the MTU to restore HVPLS hub connectivity for that PE network element. | 12-22-2011 |
20110310904 | L2 METHOD FOR PARTIAL VLAN SERVICE MIGRATION - An upgraded edge node (e.g., enhanced PBB edge node, enhanced IP/MPLS edge node) and a method are described herein for providing a VLAN service for a customer in a metro network. In addition, a metro network is described herein which includes the upgraded edge nodes, traditional PB edge nodes, and a PB domain that has PB core nodes located therein. | 12-22-2011 |
20120069740 | Relayed CSPF Computation for Multiple Areas and Multiple Autonomous Systems - Computing a constraint-based label switched path (LSP) that spans multiple areas is described. In one embodiment, a router in a first one of the multiple areas computes a path segment that meets a set of one or more constraints to at least one border router of the first area that lies in a path necessary to reach the destination. The router transmits a path computation request message to a path computation element (PCE) in a second one of the areas, which includes a set of one or more attributes for each computed path segment that are used by the PCE to compute one or more path segments towards the destination of the constraint-based LSP. The router receives a path computation reply message from the PCE that specifies a set of one or more computed path segments that meet the set of constraints and that were computed by one or more PCEs downstream from the router. The router stitches at least one of the set of computed path segments that are specified in the path computation reply message with the path segment computed by the router to form at least part of the constraint-based LSP. | 03-22-2012 |
20120069745 | METHOD AND APPARATUS TO IMPROVE LDP CONVERGENCE USING HIERARCHICAL LABEL STACKING - A method for improving LDP (Label Distribution Protocol) convergence time in an MPLS (Multi-Protocol Label Switching) network is described. An hierarchical LSP is established to transport packets belonging to a FEC attached to an egress LSR. The hierarchical LSP includes an egress LSR LSP that is common for each of the FECs attached to the egress LSR and forms a path from the ingress LSR through one or more intermediate LSRs to the egress LSR. The egress LSR LSP is used when label switching packets destined for the FECs attached to the egress LSR. The hierarchical LSP also includes a unique FEC LSP for each FEC that is used by the egress LSR to identify and forward packets to that FEC. Responsive to a topology change that changes a next-hop of the ingress LSR to reach the egress LSR, the ingress LSR modifies an entry in a forwarding structure to change the next-hop for the egress LSR LSP and does not modify substantially any forwarding structure entities for the FEC LSPs. LDP convergence time is reduced through a reduction of forwarding structure modifications after the topology change. | 03-22-2012 |
20120075986 | Fast Flooding Based Fast Convergence Architecture - Fast flooding based fast convergence to recover from a network failure. A router detects a network failure, and responsive to that failure, transmits a fast failure notification message to a set of one or more routers. The fast failure notification message includes information that identifies the network failure and also indicates that the fast failure notification message is to be flooded by the set of routers independently of convergence. The router updates a routing table to reflect the network failure. The transmission of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure. | 03-29-2012 |
20120076145 | PSEUDO-WIRE PROVIDING AN IN-BAND CONTROL CHANNEL USING AN OFFSET - A method implemented by a first provider equipment (PE) device to enable operations, administration and management (OAM) functionality over a pseudo-wire (PW) between the first PE device and a second PE device, wherein the PW traverses a packet switched network and carries control channel messages and a flow of data packets, and where the packet switched network includes nodes that use information outside a pseudo-wire label stack of the data packets for determining multi-path routing, the method including receiving a control channel message at the first PE to be forwarded over the pseudo-wire to the second PE, and prefixing the control channel message with a pseudo-flow header to ensure that the control channel message is forwarded over a same route by the nodes of the packet switched network as the data packets of the flow, thereby enabling OAM functionality to be accurately performed for the pseudo-wire. | 03-29-2012 |
20120093150 | MULTIPATH TRANSMISSION CONTROL PROTOCOL PROXY - An edge router runs a Multipath Transmission Control Protocol (MPTCP) proxy to allow for a host that implements TCP (Transmission Control Protocol) to operate normally yet reap the benefits of an MPTCP connection. An upgrade of a TCPIP stack on the host is not necessary. The edge router demultiplexes packets received from the host over a TCP connection to an MPTCP connection and multiplexes packets sent to the host over an MPTCP connection to a TCP connection. As a result, higher throughput of packet communication can be realized, for example, for improved video support. | 04-19-2012 |
20120120847 | LDP IGP SYNCHRONIZATION FOR BROADCAST NETWORKS - A network element that has a broadcast interface to a broadcast network becoming operational determines whether at least one alternate path exists to the broadcast network. The broadcast interface is to carry traffic on a label switched path. If an alternate path exists, the broadcast interface will not be advertised to the broadcast network until label distribution protocol (LDP) is operational with all neighbors on the broadcast interface. | 05-17-2012 |
20120213063 | Disjoint Path Computation Algorithm - A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP. | 08-23-2012 |
20120218884 | MPLS FAST RE-ROUTE USING LDP (LDP-FRR) - MPLS (Multiprotocol Label Switching) fast re-routing using LDP (Label Distribution Protocol) is described. A first network element in a MPLS network receives a first label advertised from a second network element in the MPLS network. The first network element computes a shortest path tree (SPT) to reach a destination network element under a potential failure condition. The second network element is a nexthop of the first network element in the computed SPT and is not upstream from the potential failure condition. The first network element advertises a second label to one or more third network elements for a backup LDP LSP (Label Switched Path) that will serve as a backup when the potential failure condition is realized. The third network element(s) are upstream neighbors on the computed SPT with respect to the first network element. The first network element installs a swap action from the second label to the first label. | 08-30-2012 |
20130003607 | E-TREE USING TWO PSEUDOWIRES BETWEEN EDGE ROUTERS WITH ENHANCED FORWARDING METHODS AND SYSTEMS - An e-tree service that includes establishing two pseudowires (PW) between edge network elements with enhanced packet forwarding is described. In one embodiment, a root PW is used for carrying packets that are sent from a root node network element, and a leaf PW is used for carrying packets that are sent from a leaf node network element in the e-tree service network. When a network element receives a packet with a destination Media Access Control (MAC) address on the logical port associated with the leaf access circuit (AC), responsive to determining that the destination MAC address corresponds to a MAC address in a MAC address table stored in the network element, and that an attribute associated with that MAC address in the MAC address table indicates the MAC address was learned from the leaf PW, the network element drops the packet. | 01-03-2013 |
20130010589 | MPLS FAST RE-ROUTE USING LDP (LDP-FRR) - MPLS (Multiprotocol Label Switching) fast re-routing using LDP (Label Distribution Protocol) is described. A first network element in an MPLS network receives a first label advertised from a second network element in the MPLS network. The first network element computes a shortest path tree (SPT) to reach a destination network element under a potential failure condition. The second network element is a nexthop of the first network element in the computed SPT and is not upstream from the potential failure condition in the computed SPT. The first network element determines that a third network element in the MPLS network is a Point of Local Repair (PLR) when the potential failure condition is realized. The first network element distributes a second label to the third network element for a backup LDP Label Switched Path (LSP) that will serve as a backup path when the potential failure condition is realized. The first network element installs a swap action from the second label to the first label. In one embodiment, the backup LDP LSP is an existing shortest path LSP from the third network element to the first network element. | 01-10-2013 |
20130010607 | SCALABLE CONNECTIVITY FAULT MANAGEMENT IN A BRIDGED/VIRTUAL PRIVATE LAN SERVICE ENVIRONMENT - A first network element that is to be coupled with a second network element over a first network in the same domain is described. The first network element includes a connectivity check detection module and a connectivity check fault state change module. The connectivity check detection module detects, according to a first protocol, a connectivity status of a local maintenance endpoint on a second network changing between not active and active. The connectivity check fault state change module creates and sends a first fault state change message, according to a second protocol, in response to the connectivity status of the local maintenance endpoint changing from not active to active instead of forwarding connectivity check messages periodically received by the first network element to a remote maintenance endpoint coupled to the second network element over a third network. | 01-10-2013 |
20130022041 | SIGNALING A LABEL SWITCHED PATH (LSP) TUNNELING MODEL - Signaling a Label Switched Path (LSP) tunneling model is described. In one embodiment, a network element that is acting as an egress network element in a Multiprotocol Label Switching (MPLS) network signals multiple LSPs for multiple disparate applications provided in the MPLS network that each require a different type of tunneling model. The network element transmits a first label mapping message for one of the LSPs that includes an indication of a first tunneling model type applicable for that LSP. That LSP is to be used to transport traffic in the MPLS network for a first one of the disparate applications that requires the indicated first tunneling model type. The network element further transits a second label mapping message for a second one of the LSPs that includes an indication of a second tunneling model type applicable for that LSP. That LSP is to be used to transport traffic in the MPLS network for a second one of the disparate applications that requires the indicated second tunneling model type. The first tunneling model type and the second tunneling model type are different. In one embodiment, the first tunneling model type is a uniform tunneling model and the second tunneling model type is a pipe tunneling model (regular pipe or short-pipe). | 01-24-2013 |
20130089094 | Method and Apparatus for Dissemination of Information Between Routers - There is provided a method for use by a first processing unit in or to be installed in a router. The first processing unit is configured or responsible for routing (or forwarding) packets to and from other routers. There may be other such first processing units in or installed in the router. In a first step (S | 04-11-2013 |
20130232259 | Method and Apparatus for Handling Network Resource Failures in a Router - There is provided a method for use by a router in a communications network. Forwarding information is maintained (S | 09-05-2013 |
20130343175 | INTERNETWORKING AND IP ADDRESS MANAGEMENT IN UNIFIED MPLS AND IP NETWORKS - IP addresses are efficiently assigned and advertised across the boundary of two network domains. The two network domains include an access network that implements MPLS-TP and a core network that implements IP, MPLS, or a combination of both. A primary BN at the domain boundary receives an assignment of an IP prefix for a VPN that connects a set of CEs to one or more SNs. The IP prefix represents a pool of IP addresses. The primary BN assigns only one IP address to both itself and a standby BN for the VPN to minimize the use of assigned IP addresses. The primary BN assigns the other IP addresses to the CEs in the VPN. The primary BN then advertises the IP prefix into the core network to enable routing of network data traffic across the network domain boundary. | 12-26-2013 |
20130343180 | INTERNETWORKING AND FAILURE RECOVERY IN UNIFIED MPLS AND IP NETWORKS - A primary border node (BN) and a standby BN are provided for internetworking two network domains, such that connectivity between the two network domains is maintained when a failure occurs in one of the network domains. The two network domains include an access network that implements MPLS-TP and a core network that implements IP, MPLS, or a combination of both. The primary BN establishes a tunnel from itself to the standby BN, and re-directs network data traffic from itself to the standby BN via the tunnel when it detects that an access node has switched connection from the primary VN to the standby BN. The primary BN also monitors its connections to the core network, and signals access nodes to switch to the standby BN if a failure is detected in these connections. | 12-26-2013 |
20140146828 | LDP IGP SYNCHRONIZATION FOR BROADCAST NETWORKS - A network element that has a broadcast interface to a broadcast network becoming operational determines whether at least one alternate path exists to the broadcast network. The broadcast interface is to carry traffic on a label switched path. If an alternate path exists, the broadcast interface will not be advertised to the broadcast network until label distribution protocol (LDP) is operational with all neighbors on the broadcast interface. | 05-29-2014 |
20140341016 | METHOD AND APPARATUS FOR ENABLING EFFICIENT RESOURCE ALLOCATION - Embodiments of the present disclosure include a method and intermediate label switch router (LSR) for enabling efficient resource allocation for point to multi-point signaling. In one embodiment, upstream traffic specification information associated with a plurality of spoke nodes is received. The upstream traffic specification information is sent to a hub. Upstream flow specification information is received from the hub. The upstream flow specification information is used to allocate resources among the plurality of spoke nodes proportionally or in accordance with a resource sharing mode. | 11-20-2014 |
20140348002 | RELAYED CSPF COMPUTATION FOR MULTIPLE AREAS AND MULTIPLE AUTONOMOUS SYSTEMS - A method in a router for participating in computation of a constraint-based label switched path (LSP) that spans a plurality of areas to reach a destination is described. The method comprises computing a path segment that meets a set of one or more constraints to at least one border router of the first area, transmitting a path computation request message to a path computation element in a second one of the plurality of areas, receiving a path computation reply message from the path computation element, and stitching at least one of the set of computed path segments that are specified in the path computation reply message with the path segment computed by the router to form at least part of the constraint-based LSP. | 11-27-2014 |
20150030020 | METHOD AND APPARATUS FOR USING ENTROPY LABELS IN SEGMENT ROUTED NETWORKS - A method and apparatus for using entropy labels in segment routed networks is disclosed. A single ELI and a single EL are provided for a label stack. The ELI and EL are inserted directly below a top-most label in the label stack. | 01-29-2015 |