Method for supporting foreign protocols across backbone network by combining and transmitting list of destinations that support second protocol in first and second areas to the third area

• US 5,557,745 A
• Filed: 03/20/1995
• Issued: 09/17/1996
• Est. Priority Date: 09/04/1990
• Status: Expired due to Term

• Current Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Perlman, Radia J., Shand, Ian M. C., Gunner, Christopher W.
• Primary Examiner(s): AN, MENG AI T
• Application Number:
  US08/407,802
• Time in Patent Office: 547 Days
• Field of Search: 395/800, 395/200, 395/200.01, 395/200.02, 395/200.1, 395/200.15, 395/200.18, 370/54, 370/58, 370/60, 370/79, 370/85.12, 370/85.13, 370/85.14, 370/89, 370/86, 370/90, 370/93, 370/94, 370/94.1, 340/825.4
• US Class Current: 709/242
• CPC Class Codes: H04L 45/02 Topology update or discovery
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/52 Multiprotocol routers
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method of transferring foreign protocol information across a hierarchical backbone network is disclosed. The hierarchical backbone network operates according to a first protocol and includes multiple areas, some of which have a destination that operates according to a second protocol. Additionally, each area has at least one router located therein. The locations of the destinations in each area are identified to the router in that area. Information that identifies the locations of the destinations in each area is transferred to a router in each of the other areas regardless of whether the destinations are located in the same area as the router. Finally, information formatted according to the second protocol is transferred among any of the destinations.

Claims

1. A method of transferring information across a computer network that operates according to a first protocol, said computer network being comprised of areas having a plurality of destinations, with each area having at least one destination and each destination having a location within said areas, some of said destinations operating according to a second protocol, and each of said areas having at least one router connected to said destination for supporting both said first protocol and said second protocol located therein, said method of transferring information comprising the steps of:

generating by a first router a first list of the location of each destination in a first area supporting said second protocol, said first router supporting both said first protocol and said second protocol in said first area;

transmitting the first list from said first router to a second router supporting both said first protocol and said second protocol in a second area;

generating, by said second router in said second area, a second list of the location of each destination within said first area and said second area supporting the second protocol;

transmitting the second list from the second router to a third router supporting both said first protocol and said second protocol in a third area;

transferring information identifying destinations in said second area and third area that operate under said second protocol from said router in said second area to said router in said first area.

2. The method of transferring information of claim 1, wherein said first list includes an identification of at least one router in said first area and said second list includes an identification of at least one router in said second area and said first list.

3. The method of transferring information of claim 1, wherein said first protocol destinations manage information transfer costs according to a first scheme and the second protocol manage information transfer costs according to a second scheme, said method further comprising the steps of:

encoding cost information by said computer network to produce encoded cost information relating to data transmission to each of said destinations with said information that identifies the locations of said destinations; and

optimizing route selection of data packets transferred between destinations operating under said second protocol based on said cost information.

4. The method of transferring information of claim 3, wherein said encoded cost information for said second protocol cost information is expressed in hops between points and wherein said step of optimizing route selection includes the step of adding one to the number of hops to reach a given destination before announcing an existence of said given destination to another router.

5. A method of transferring information across a computer network operating under a first protocol, said computer network including a plurality of areas, each of said areas including at least one destination and each of said destinations having a location within said areas, each of said areas having at least one router connected to said destination, some of said routers operating under a second protocol, said routers transmitting link state packets, said method of transferring information comprising the steps of:

encoding by said router in a second area said link state packets from said router in a first area having said destinations attached thereto with transfer information including an identity of said location of said destinations in the first area supporting said second protocol, wherein a unique designator identifying the destination the router to which said destination is attached;

transmitting said link state packets to at least one other router connected thereto in a third area, wherein said at least one other router receives the link state packets and decodes said transfer information;

establishing a tunnel between one of said routers in said first area and a router in a second area;

transferring information identifying destinations in said second area that operate under said second protocol and destinations in said third area that operate under said second protocol from said router in said second area to said router in said first area.