128 Technology, Inc.

Acme Packet, Inc.

Priority Call Management, Inc.

Boston Technology, Inc.

Lhs Group, Inc.

Primary Network, Inc. D/b/a Acme Packet, Inc.

Robert F Penfield

Patrick John MeLampy

Hadriel S Kaplan

Patrick Timmons

Abilash Menon

Michael Baj

Peter Commerford

Ephraim Webster Dobbins

Clifford M Spencer

Cynthia E Arens

Stephen T Voto

Rebecca A Pedersen

Andrew D Ory

Stephen Norton

Prashant Kumar

David Gray

Anna Yungelson

Scott A McCulley

Ryan Koss

Allen T Arumainayagam

Kevin P Klett

Mariana Benitez Pelaez

Gregory David Schumacher

Thomas E Sullivan

Biao Ren

Kenneth Kuenzel

Mohiuddin Mohammed Khan

Ajay Manuja

Patrick John Melampy

Ajay Manju

Stephen Gerard Reppucci

Jose Capo

Anthony N Deigh

Jos&eacute; J Cap&oacute;

Theresa H Ryan

Duncan S Fisher

Jeffrey G Gibson

Todd Sherer

Ping Zhou

Pietro Botticelli

Francisco Jose Mendez Cirera

Patrick J Melampy

Jose J Capo

Patric Timmons

David Michael Gray

Mohiuddin M Khan

Ephraim W Dobbins

Stephen E Norton

Peter S Cummerford

Peter S Commerford

In exemplary embodiments of the present invention, a router determines whether or not to establish a stateful routing session based on the suitability of one or more candidate return path interfaces. This determination is typically made at the time a first packet for a new session arrives at the router on a given ingress interface. In some cases, the router may be configured to require that the ingress interface be used for the return path of the session, in which case the router may evaluate whether the ingress interface is suitable for the return path and may drop the session if the ingress interface is deemed by the router to be unsuitable for the return path. In other cases, the router may be configured to not require that the ingress interface be used for the return path, in which case the router may evaluate whether at least one interface is suitable for the return path and drop the session if no interface is deemed by the router to be suitable for the return path.

Reverse forwarding information base enforcement

A router advertises an aggregated service or route that can be evaluated by other routers as a unitary segment rather than as a group of individual links/paths associated with the aggregated service or route. The aggregated service or route can be based on service and topology state information received from one or more other routers and can be advertised with the router as the nexthop for the aggregated service or route. The router can advertise an aggregated metric for the aggregated service or route for use in such evaluation. An aggregated route can be associated with different aggregated metrics for different services.

Routing using segment-based metrics

A routing system for implementing a service and topology exchange protocol (STEP) includes a primary STEP server configured to maintain a STEP repository and a plurality of routers, with each router including a STEP client in communication with the primary STEP server. The STEP client of each router is configured to transmit, using STEP, STEP documents containing service and topology state information for at least one route or service available through the router to the primary STEP server for storage in the STEP repository. The primary STEP server is configured to transmit to the STEP client of each router, using STEP, service and topology state information from the STEP repository for at least one other router based on configured relationships between routers. Each router is configured to make routing decisions based at least in part on the service and topology state information from the at least one other router.

Service and topology exchange protocol

Routing packets by a router involves establishing a first flow configured for forwarding the packets from a first ingress interface to a first egress interface of the router; determining a condition to modify the first flow; deactivating the first flow; establishing a second flow configured for forwarding the packets from at least one of (1) the first ingress interface to a second egress interface, (2) a second ingress interface to the first egress interface, or (3) a second ingress interface to a second egress interface; and activating the second flow.

Flow modification including shared context

A method and apparatus form and/or define a network topology in a Layer 3 network with a plurality of nodes, where each node has at least one interface. To that end, the method defines a plurality of neighborhoods, and assigns at least one interface of each node to at least one of the neighborhoods. The method also assigns a communication role to each interface so that each communication role is effective relative to one of the plurality of neighborhoods. The method then enables communication between the interfaces of the plurality of nodes as a function of the neighborhoods and the communication roles.

Network neighborhoods for establishing communication relationships between communication interfaces in an administrative domain

A routing system for routing packets for a route or service comprises a plurality of routers including a source router, wherein the source router is configured to receive, using a service and topology exchange protocol, service and topology state information from a STEP repository for at least one other router based on configured relationships between routers; determine a first path to a destination for a route or service based on the service and topology state information, the first path including an ordered list of successive routers to receive a packet associated with the route or service starting with a first successive router and ending with a destination router; and transmit a packet toward the first successive router with first metadata including a list of at least one remaining router of the ordered list of routers to receive the packet associated with the route or service. Each successive router, starting with the first successive router, is configured to receive a packet and determine if the router is the destination router based on metadata associated with the received packet, and when the router is not the destination router, forward the packet toward a next successive router in the ordered list of routers.

Source-based routing

A routing system for distributing multicast routing information for a multicast service includes a plurality of routers including a multicast source router and a plurality of multicast receiver routers, the plurality of routers providing a multicast service, wherein the routers are configured to exchange multicast information associated with the multicast service including identification of multicast sources and the multicast receivers.

Distribution of multicast information in a routing system

A method routes packets from a source to a destination across an IP network having a plurality of nodes (including the source and destination), and a plurality of network segments interconnecting the plurality of nodes. The source and destination are configured to use a given service. To those ends, the method receives information relating to the given service, and forms a path between the source and the destination. The path includes a) at least one intermediate node between the source and the destination and b) a plurality of specific network segments extending from the source to the destination. The plurality of specific network segments are a sub-set of the plurality of network segments. To form the path, the method assigns the plurality of specific network segments to the network path between the source and the destination as a function of the information relating to the given service.

Service related routing method and apparatus

A routing system for implementing a service and topology exchange protocol (STEP) comprises a primary STEP server configured to maintain a STEP repository and a plurality of routers, each router including a STEP client in communication with the primary STEP server. The STEP client of each router is configured to transmit, using the service and topology exchange protocol, service and topology state information for at least one route or service available through the router to the primary STEP server for storage in the STEP repository. The primary STEP server is configured to determine, for each router, whether the STEP repository includes any service and topology state information changes for the router based at least in part on the service and topology state information received from the routers and to transmit to the STEP client of each router for which there are service and topology state information changes, using the service and topology exchange protocol, only the service and topology state information changes.

Central authority for service and topology exchange

Growing community of inventors

Maynard, MA, United States of America

Robert F Penfield