Enterasys Networks, Inc.

Cabletron Systems, Inc.

Other

Enterasys, Inc.

Enterasys Networkds, Inc.

Extreme Networks, Inc.

Brendan J Fee

Kurt A Dobbins

Chris Oliver

David L Cullerot

Michael Skubisz

Kevin Yohe

Theodore C Len

David H Bahi

Philip Andlauer

Thomas A Grant

Laura Kane

David Ruffen

Dave Arneson

Pat Mullaney

Richard W Graham

John Roese

David E Frattura

William T Haggerty

David Harrington

Richard Bussiere

David Belser

Jeff Cioli

John-Paul Gorsky

Anja A Allen

William A Edmondson

Dorion W Carr

David J Ruffen

John J Roese

David Frattura

Roger P Durand

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 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.

A method for location discovery in a data network includes receiving, at a first device, connection information from a neighboring network device and determining a physical location of the first device based on the connection information. The method can include receiving, at the first device, the physical location transmitted from the neighboring network device. The method can further include associating a level of trust with the physical location based on the neighboring network device. The first device be one of a variety of devices, such as a router, a switch, a network entry device, a firewall device, or a gateway.

Location discovery in a data network

Distributed connection-oriented services for switched communications networks

An apparatus and method for allocating the performance of applications in a networking chassis among one or more modules in the chassis. In particular, the system acts as a chassis agent for performing network management functions. The agent performs a discovery function whereby each module discovers the location and current utilization of resources and applications for itself and transmits that information to other modules, and wherein each module maintains a slot table of such information for all modules. Based on the information in the slot table, each module performs an election function for allocating applications among the various modules in the chassis. The agent uses MIBs to gather information about the chassis and to effect control on the chassis, wherein each managed object is registered both locally and remotely in a MIB tree maintained on each module, and the data is maintained locally on the module on which the managed object resides. The system enables the chassis to be managed &ldquo;as a whole&rdquo; while the management functions are distributed across the system, and the system is both fault tolerant and enables ready expansion and modification of the management applications.

Distributed chassis agent for network management

A method and apparatus are provided for connection-oriented switching in a communications network wherein a pre-established path is established between a select pair of an ingress switch and an egress switch. The use of pre-established paths enables a reduction in the total number of connections required inside the switch cloud, reduces the CPU load on trunk switches, and shortens the time for connection setup. In the embodiment described, the DA/SA fields of a MAC frame data packet are replaced with a &ldquo;virtual path&rdquo;, which identifies the pre-established path between the ingress and egress switches. A &ldquo;virtual circuit&rdquo; is provided in another field of the modified packet which specifies the out-port and out-header on the egress switch for demultiplexing the modified packet upon receipt at the egress switch. The virtual circuit is exchanged between the ingress and egress switches at connection setup. The virtual path is assumed to already be in place, and known to both switches, prior to connection setup.

Aggregation of data flows over a pre-established path to reduce connections

A method and apparatus are provided for connection-oriented switching in a communications network wherein a pre-established path is established between a select pair of an ingress switch and an egress switch. The use of pre-established paths enables a reduction in the total number of connections required inside the switch cloud, reduces the CPU load on trunk switches, and shortens the time for connection setup. In the embodiment described, the DA/SA fields of a MAC frame data packet are replaced with a 'virtual path', which identifies the pre-established path between the ingress and egress switches. A 'virtual circuit' is provided in another field of the modified packet which specifies the out-port and out-header on the egress switch for demultiplexing the modified packet upon receipt at the egress switch. The virtual circuit is exchanged between the ingress and egress switches at connection setup. The virtual path is assumed to already be in place, and known to both switches, prior to connection setup.

Aggregation of mac data flows through pre-established path between

Method and apparatus providing for load sharing in redundant communication networks. The method and apparatus may include detection of redundant communication links in the network topology and sharing communication load over those links. This may be accomplished through assignment of unique labels to each link in a group of redundant links and assignment to each data packet of a value corresponding to the label on just one of the links; the packet being forwarded on only that link. The method and apparatus are also suited to quick recovery from a change in state of a network topology.

Load sharing for redundant networks

Distributed connection-oriented services for switched communications

An apparatus and method for allocating the performance of applications in a networking chassis among one or more modules in the chassis. In particular, the system acts as a chassis agent for performing network management functions. The agent performs a discovery function whereby each module discovers the location and current utilization of resources and applications for itself and transmits that information to other modules, and wherein each module maintains a slot table of such information for all modules. Based on the information in the slot table, each module performs an election function for allocating applications among the various modules in the chassis. The agent uses MIBs to gather information about the chassis and to effect control on the chassis, wherein each managed object is registered both locally and remotely in a MIB tree maintained on each module, and the data is maintained locally on the module on which the managed object resides. The system enables the chassis to be managed 'as a whole' while the management functions are distributed across the system, and the system is both fault tolerant and enables ready expansion and modification of the management applications.

Distributed chassis agent for distributed network management

An apparatus and method for allocating the performance of applications in a networking chassis among one or more modules in the chassis. In particular, the system acts as a chassis agent for performing network management functions. The agent performs a discovery function whereby each module discovers the location and current utilization of resources and applications for itself and transmits that information to other modules, and wherein each module maintains a slot table of such information for all modules. Based on the information in the slot table, each module performs an election function for allocating applications among the various modules in the chassis. The agent uses Management Information Bases MIBs to gather information about the chassis and to effect control on the chassis, wherein each managed object is registered both locally and remotely in a MIB tree maintained on each module, and the data is maintained locally on the module on which the managed object resides. The system enables the chassis to be managed 'as a whole' while the management functions are distributed across the system, and the system is both fault tolerant and enables ready expansion and modification of the management applications.

A fault tolerant system management bus architecture for a networking chassis includes a primary path for transmission of system management information and a secondary path for transmission of system management information in the event of failure of the primary path. The primary path includes a first microprocessor controller, coupled between the first system management bus and the processor located on a networking module. The secondary path for transmission of system management information includes a second microprocessor controller system and a dual-port memory. The second microprocessor control system is coupled to the second system management bus and to the dual-port memory. The dual-port memory is also coupled to the processor located on the networking module. The dual-port memory provides the interface between the CPU in the networking module and the second microprocessor control system, thus providing isolation and allowing the memory to be accessible by either processor. Environmental information and module identification information are stored in the dual-port memory. In the event of failure of the primary transmission path, the environmental information and module identification information can be accessed and transmitted over the backup transmission path.

Chassis fault tolerant system management bus architecture for a

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Nashua, NH, United States of America

Brendan J Fee