Nortel Networks Corporation

Avaya Inc.

Avaya Holdings Limited

Dwight D Jamieson

Rong R Wang

Nevein T Sultan

Valerie A Simpson

Bilel N Jamoussi

Bernard Francois St-Denis

Matthew Yuen

Michael Scott Pegrum

Gregory V Wright

Paul J Beaubien

A method and system enables policy-based traffic forwarding in a data network by implementing policy-based control over propagation of LSA messages through the data network. A route tag is asserted in respect of a link state advertisement (LSA) message advertising a network address. Propagation of the LSA through the data network is controlled using the asserted internal route tag. At each hop, a policy decision affecting the forwarding of the LSA is made. Exemplary policy decisions include, Pass and Discard. In addition, the forwarding table may be updated using the route and address information contained in the LSA. In this case, routes entered in the forwarding table may be tagged as an inclusion route or an exclusion route. This may be based on the value of an exclusion route flag, which can, for example, be provided as a binary '0' or '1' inserted into an unused portion of the options field of the LSA.

Policy-based forwarding in open shortest path first (OSPF) networks

In methods and apparatus for acquiring VPN reachability information at a node of a data network, a VPN reachability information request is transmitted from a requesting node. The VPN reachability information request comprises a VPN identifier. Other nodes of the data network receive the VPN reachability information request and, if they have reachability information relevant to that VPN, they transmit such information to the requesting node where it is received and stored. The invention can be used in MPLS VPN architectures.

Distribution of reachability information in data virtual private networks

A data plane architecture enables IP applications, hosted on any processor within a network element, to define steering policies that may be implemented in the data plane. The steering policies enable the applications to define steering policies containing both attributes and actions. The attributes are used to identify the packets and the actions are used to define how the data plane of the network element should handle the packets. The steering policies are implemented in the data plane of the network element by a data path policy steering process. The data path policy steering process operates to implement steering policies defined by applications to cause IP termination to occur at any processor on the network element or optionally at a processor off the network element.

Application specified steering policy implementation

In methods and apparatus for acquiring VPN reachability information at a node of a data network, a VPN reachability information request is transmitted from a requesting node. The VPN reachabinty information request comprises a VPN identifier. Other nodes of the data network receive the VPN reachability information request and, if they have reachability information relevant to that VPN, they transmit such information to the requesting node where it is received and stored. The invention can be used in MPLS VPN architectures.

A method and apparatus provides protection against resource failures in Open Shortest Path First (OSPF) networks, without increasing the complexity of the network topology and/or management. An internal router (IR) automatically maintains a back-up link in a dormant state until a network failure affecting communications with a primary adjacent area border router (ABR) is detected. Upon detection of the network failure, the IR activates the back-up link in order to enable traffic flow to an alternate adjacent ABR, which by-passes the network failure. Upon recovery of communications with the primary adjacent ABR, the IR automatically deactivates the back-up link and resumes traffic flow through the primary adjacent ABR. As a result, traffic is forwarded into the back-up link only when communications with the primary adjacent ABR has failed, thereby maintaining simplicity in the network topology, and minimizing network management and administration requirements.

Dormant backup link for OSPF network protection

A virtual private network enables private communications over a shared MPLS network between two or more private networks. The virtual private networks include a first router connected to the shared MPLS network and configured to dynamically distribute first router VPN information across the shared MPLS network. The first router VPN information includes a VPN identifier which is assigned to the first router. The VPN also includes a second router connected to the shared MPLS network and and configured to dynamically distribute second router VPN information across the shared MPLS network. The second router VPN information includes a VPN identifier which is assigned to the second router and which is identical to the VPN identifier assigned to the first router. The first and second routers are also configured to establish label switched paths therebetween. A method of automatically configuring virtual private networks over a shared MPLS network includes creating a link between a private network router and a shared network router. It also includes assigning a VPN identifier to the shared network router, assigning the same VPN identifier to at least one other shared network router, determining all shared network routers which are assigned the same VPN identifier, and creating at least two label switched paths between the shared network router and the other shared network routers.

Multi-protocol label switching virtual private networks

A system and method of automatically configuring virtual private networks is provided. The virtual private networks disclosed, include multiple routers selectively connectable to the shared network, such that each of the routers is assigned at least one: shared network address, private network address and virtual private network identifier. Each router includes a controller configured to communicate a router configuration message over the shared network to other members of the same virtual private network. The router configuration message informs the other members of the virtual private network the address of the router and what devices are connected to the router.

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Ottawa, Canada

Dwight D Jamieson