Alcatel Lucent

Nortel Networks Corporation

Alcatel Canada Inc.

Cheng-Yin Lee

Stefaan Jozef De Cnodder

Loa Andersson

Fayaz Kadri

Glenn C Morrow

Amr Elkady

This invention is applicable to a Virtual Private LAN service built using multiple point-to-point Ethernet services from a network operator, where the bridging and the transport/tunneling of Ethernet frames to a remote site are decoupled. The learning bridge function (including MAC address learning and flooding) is performed at customer equipment CE devices, while the tunneling is performed at provider edge PE nodes. The models described here for this VPN refer to hub redundancy, site-to-site SLA guarantees and address discovery in the case of hybrid connections.

Hybrid virtual private LAN extensions

A system and method are provided for forwarding packets through a fully meshed communication network when the destination MAC address may not be known. Each network element maintains a mapping of MAC addresses and IP addresses, each MAC address having an associated IP address which indicates to where packets are to be forwarded. If a network element receives a packet but has not yet associated an IP address with the destination MAC address of the packet, then the network element forwards the packet along a tree. If a network element receives a packet and has associated an IP address with the destination MAC address, in other words has learned of the IP address for the MAC address, the network element sends the packet directly to the IP address unless a direct link to the IP address is not available. If a direct link is not available, the network element forwards the packet along the tree. A network element receiving a packet from an attachment circuit encapsulates its own IP address in the message, permitting other network elements to learn of the IP address associated with the source MAC address. The invention provides reliable forwarding of packets to both known and unknown destination MAC addresses, while taking advantage of shortest paths provided by a fully meshed network.

Low latency working VPLS

The present invention discloses a solution which delivers routing systems with less path setup latency and causes them to be less susceptible to network loading, by providing them the ability to setup diverse paths as a result of specifying network resources to exclude as part of a path setup. The invention proposes an extension to RSVP-TE in the form of a new RSVP-TE object, known as an Exclude Route Object, which will allow, in a path setup request, the specification of a set of abstract nodes and resources to be explicitly excluded from the path. Additionally, the invention introduces a second type of exclusion which is achieved through a modification to the existing Explicit Route Object (ERO) by allowing a node to specify, in a path setup request, the exclusion of certain abstract nodes and resources between a specific pair of abstract nodes within an Explicit Route Object.

Prohibit or avoid route mechanism for path setup

A method of processing OAM messages by network elements in a communications network is described. Elements in the network are provided with configuration information respecting OAM messages together with connection signaling upon setting up a call through the network. Each network element interprets the OAM messages and derives therefrom configuration information for use in executing an OAM function.

Extensible OAM support in MPLS/ATM networks

Location update messages for a mobile node can be made interceptible by routers which form tunnels for communication with the mobile node. A correspondent agent intercepts a Binding Update with a Router Alert and binds the address of the mobile node with a care of address for the mobile node provided in the Binding Update. The correspondent agent will thereafter intercept messages from its correspondent host destined for the mobile node and redirect them to the care of address thereby bypassing the home agent of the mobile node. A border router intercepts a Registration Request with Router Alert and binds the address of the mobile node with a care of address for the mobile node. If a binding existed previously, then the border router terminates the Request. Otherwise, the Request is forwarded to the home agent of the mobile node after substituting its own address for the care of address.

Method and program code for communicating with a mobile node through tunnels

A method for avoiding loops from forming when setting up label switched paths is provided. The method uses a Label Splicing Message is followed by an Acknowledgment message to determine if loops are formed in the process of joining a new node or subtree to a multicast MPLS tree. By verifying that the path towards the root of the MPLS tree is loop-free during the construction of the tree, this method complements the loop detection mechanism provided by the label switched protocol (LDP).

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Ottawa, Canada

Cheng-Yin Lee