Cabletron Systems, Inc.

Enterasys Networks, Inc.

Other

Enterasys, Inc.

Michael Skubisz

Kurt A Dobbins

David L Cullerot

Brendan J Fee

Chris Oliver

Kevin Yohe

Theodore C Len

Laura Kane

Philip Andlauer

David H Bahi

Thomas A Grant

David Ruffen

Phil Andlauer

Brian St Pierre

Edward F Holmes

David J Ruffen

Connection-oriented services for packet switched data communications networks are provided, including distributed MAC and protocol alias addresses discovery. Link state topology exchanges provide each switch with network topology graphs to determine paths from source to destination end systems. Broadcast frames are resolved to unicast frames to reduce broadcast traffic. Policy restrictions may be applied prior to connection setup. Connection management includes source-routed mapping of connections on the desired path. Distributed call rerouting is provided so switches receive topology change notifications and unmap failed link connections. Broadcast/unknown services provide non-resolvable packet restricted flooding. Connection-oriented switching is provided based on source and destination MAC addresses. Resolution of networks outside the switch domain is enabled by listening for network and server route advertisements and maintaining best routes to the networks and servers. Route and path metrics may be combined to determine paths from access switches to egress switches connected to the external network.

Distributed connection-oriented services for switched communication networks

Method and apparatus for ad hoc cooperative routing in an IP network. Included is an emergency stand alone (ESA) system that provides a bypass to a failed TDM switch for multiple communication devices in communication with one or more TDM switches. One or more internet protocol media gateways communicate a multicast signal upon the failure of a switch. The multicast initiates Voice over IP communication between endpoints, bypassing the failed switch.

System for VOIP based emergency stand alone service

Method and apparatus providing connection-oriented services for packet switched data communications networks. Directory services include distributed discovery of MAC addresses and protocol alias addresses. Topology services include a link state topology exchange among switches, which provides each switch with a complete topology graph of the network. This enables an access switch receiving a data packet to determine a complete path from a source end system to a destination end system. Another service includes resolution of broadcast frames to unicast frames, in order to reduce the amount of broadcast traffic. Policy restrictions may be applied prior to connection setup. Path determination services enable multiple paths from a source to a destination. Connection management includes source routed mapping of connections on the desired path. A distributed call rerouting service is provided wherein if a link on an active path fails, each switch receives a topology change notification and unmaps any connection involving the failed link. A broadcast/unknown service provides restricted flooding of nonresolvable packets. Furthermore, connection-oriented switching is provided based on the source and destination MAC addresses as a connection identifier. Still further, resolution of networks outside the switch domain is enabled by access switches listening for network and server route advertisements and maintaining best routes to said networks and servers. The best route metrics may be combined with best path metrics to determine a path from a first access switch to an egress switch connected to the external network.

Distributed connection-oriented services for switched communications networks

Method and apparatus for establishing restricted broadcast groups in a switched network. The method assigns different virtual LAN identifiers (VLAN-IDs) to different subsets of associated end systems or access ports. Tables are maintained for mapping the VLAN-IDs with associated end systems and access ports. When a broadcast packet is received at a first switch, it is encapsulated with a VLAN header, including the VLAN-IDs, and sent out a multicast channel to all other switches in the network (domain). The original packet is sent out the other access ports of the receiving switch for the designated VLAN-IDs. The switches receiving the VLAN packet remove the header and send the original packet out access ports associated with the VLAN-IDs extracted from the header. The method provides a mechanism for forwarding broadcast packets of a protocol not supported by the switching mechanism, as well as multicast packets and unicast packets from undiscovered end systems.

Method for establishing restricted broadcast groups in a switched network

Distributed connection-oriented services for switched communications

Growing community of inventors

Durham, NH, United States of America

Michael Skubisz