| Patent application number | Description | Published |
|---|
| 20080219153 | Constructing a repair path in the event of failure of an inter-routing domain system link - An apparatus and method as described for constructing a repair path for use in the event of failure of an inter-routing domain connection between respective components in first and second routing domains of a data communications network. The apparatus is arranged to assign a propagatable repair address for use in the event of failure of the inter-routing domain connection and to propagate the repair address via data communications network components other than the inter-routing domain connection. | 09-11-2008 |
| 20080298362 | SESSION BORDER CONTROL USING MULTIPLE PROCESSORS - In one embodiment, a router receives a call request for establishing a multimedia exchange between two remote endpoints. The router selects a processing entity to manage a subset of connections with the remote endpoints according to an endpoint identification such as a remote address included in the call request. A different processing entity manages the remaining connections with the remote endpoints. Accordingly, the load of managing signaling for establishing the multimedia exchange is balanced between a plurality of processing elements that appear externally as a single entity such that modification of remote endpoint behavior is not required. | 12-04-2008 |
| 20090046723 | DISTINGUISHING BETWEEN CONNECTIVITY VERIFICATION AVAILABILITY AND FORWARDING PROTOCOL FUNCTIONALITY IN A COMPUTER NETWORK - In one embodiment, a local network device may determine an inability to establish a connectivity verification protocol (e.g., Bidirectional Forwarding Detection, “BFD”) session to a remote network device, such as from unreturned control messages. In response, the local network device may send at least one connectivity verification protocol echo message to the remote network device destined to be returned to the local network device and forwarded using a forwarding protocol. In response to receiving or not receiving the echo message, the local network device may thus determine whether the forwarding protocol is functioning between the local and remote network devices. In this manner, the local network device may determine whether an inability to establish a connectivity verification protocol session is due to an inability to forward packets between the devices, or due to the connectivity verification protocol not working (or not being configured) on the remote network device. | 02-19-2009 |
| 20090147674 | LOOP PREVENTION TECHNIQUES USING ENCAPSULATION MANIPULATION OF IP/MPLS FIELD - In one embodiment, an edge device communicates with a neighboring routing domain. A failure that prevents communication between the edge device and the neighboring routing is detected. When the edge device thereafter receives a data packet that is directed to the neighboring routing domain, it determines if the received data packet was rerouted to the edge device from another edge device coupled to the neighboring routing domain. If the received data packet was not rerouted to the edge device from another edge device coupled to the neighboring routing domain, the edge device reroutes the received data packet to another edge device for forwarding to the neighboring routing domain. However, if the received data packet was rerouted to the edge device from another edge device coupled to the neighboring routing domain, the edge device prevents the received data packet from being rerouted a second time to prevent loops. | 06-11-2009 |
| 20090245259 | FAST REROUTE (FRR) PROTECTION AT THE EDGE OF A RFC 2547 NETWORK - In one embodiment, an edge device in a first routing domain is configured to communicate with a second routing domain via a data link. The edge device receives a data packet containing a destination address that is reachable via the second routing domain and an indication that the data packet is a protected packet that was previously rerouted from another edge device in the first routing domain via a Multi-Protocol Label Switching (MPLS) Fast Reroute (FRR) backup path. The edge device determines if communication with the second routing domain is still available via the data link, and if so, removes the indication that the data packet is a protected packet and forwards the data packet to the second routing domain, and, if not, drops the data packet to prevent the data packet from being rerouted a second time in the first routing domain on another MPLS FRR backup path. | 10-01-2009 |
| 20100118732 | LOOP PREVENTION TECHNIQUE FOR MPLS USING SERVICE LABELS - In one embodiment, a loss of communication is detected between a first edge device of a computer network and a neighboring routing domain. A data packet is received at the first edge device, where the received data packet contains a destination address that is reachable via the neighboring routing domain. A determination is made whether a service label is located in a Multi-Protocol Label Switching (MPLS) label stack included in the received data packet. A service label in the MPLS label stack indicates that the received data packet was previously rerouted in accordance with fast reroute (FRR) operations. In response to a determination that the received data packet does not include a service label in the MPLS label stack, the received data packet is rerouted to a second edge device of the computer network for forwarding to the neighboring routing domain. | 05-13-2010 |
| 20100238788 | Connection verification for MPLS label switched paths and pseudowires - In one embodiment, a connection verification (CV) message is initiated from an initiating maintenance end point (MEP) for an MPLS LSP, the CV message carried in a packet having a time-to-live (TTL) value of 1. Each maintenance intermediate point (MIP) along the MPLS LSP receives the packet and decrements the TTL, and in response to determining that the TTL equals 0, examines a payload of the packet to determine that the packet carries the CV message. The MIP may then append its MIP ID to a route record field of the payload having any previous MIP IDs of upstream MIPs, and forwards the CV message downstream along the MPLS LSP in a packet having a TTL value of 1. The end MEP receives the CV message, and sends a CV reply having the route record field with MIP IDs and an end MEP ID to the initiating MEP. | 09-23-2010 |
| 20100238812 | Operating MPLS label switched paths and MPLS pseudowire in loopback mode - In one embodiment, an initiating maintenance end point (MEP) may transmit a lock message to lock a circuit traversing one or more maintenance intermediate points (MIPs) between the initiating MEP and an end MEP. The initiating MEP may then transmit an in-band packet containing a loopback request to a particular MIP along the circuit using a particular time-to-live (TTL) value in the packet to reach the particular MIP. Upon receiving the packet at the particular MIP, and in response to determining that the TTL has expired, the particular MIP inspects the packet to discover the loopback request, and correspondingly operates in a loopback mode. | 09-23-2010 |
