Method of Operating a Network

• US 20070297405A1
• Filed: 12/08/2005
• Published: 12/27/2007
• Est. Priority Date: 12/31/2004
• Status: Active Grant

• Current Assignee: British Telecommunications PLC (BT Group PLC)
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: He, Liwen
• Granted Patent: US 7,920,558 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/12 Shortest path evaluation
• CPC Class Codes: H04L 45/124 using a combination of metrics
• CPC Class Codes: H04L 45/44 Distributed routing
• CPC Class Codes: H04L 45/52 Multiprotocol routers

Abstract

A method of operating a data network 100, of the type in which a number of inter-connected router devices (115-117, 123-124, 131-133, 141-145) forward received packets of data towards a destination node in accordance with a routing table associated with each router. The method comprises: assigning a trust value to one or more other router devices, or links between router devices, in the network; calculating a route metric in respect of one or more paths for forwarding on received data packets for onward transmission towards a specified destination; and selecting a next hop destination for onward transmission of each such received packet to be forwarded on the basis of the calculated route metric for each applicable path, wherein the or each route metric is calculated in dependence upon the trust value assigned to one or more of the router or routers within each such path.

Claims

1. A method of operating a data network, of the type in which a number of interconnected router devices forward received packets of data towards a destination node in accordance with a routing table associated with each router, the method comprising:

assigning a trust value to one or more other router devices, or one or more links between router devices, in the network;

calculating a route metric in respect of one or more paths for forwarding on received data packets for onward transmission towards a specified destination; and

selecting a next hop destination for onward transmission of each such received packet to be forwarded on the basis of the calculated route metric for each applicable path, wherein the or each route metric is calculated in dependence upon the trust value assigned to one or more of the router or routers or link or links within each such path.

2. A method as claimed in claim 1 wherein the packets of data are transmitted over the network using the Internet Protocol.

3. A method as claimed in claim 1 wherein the level of trust is based on a number of factors.

4. A method as claimed in claim 3 wherein some of the factors vary only slowly with time and some vary much more quickly.

5. A method as claimed in claim 1 wherein each router generates a trust value based on a number of factors only in respect of a relatively small number of neighbouring router devices and communicates this information to more distant routers.

6. A method as claimed in claim 1 wherein each router assigns a trust value to every other peer router device in the network.

7. A method according to claim 6 wherein the trust values assigned by each router to every other router device are not communicated to any other router devices in the network.

10. A computer program or suite of programs for causing a router device or devices to carry out the method of claim 1 during execution of the program or programs.

11. Carrier means carrying the computer program or suite of programs of claim 10.

8. A method of operating a router device, within a data network of the type in which a number of inter-connected router devices forward received packets of data towards a destination node in accordance with a routing table associated with each router device, the method comprising:

assigning a trust value to one or more other router devices in the network or to one or more links between router devices within the network;

calculating a route metric in respect of one or more paths for forwarding on received data packets for onward transmission towards a specified destination; and

selecting a next hop destination for onward transmission of each such received packet to be forwarded on the basis of the calculated route metric for each applicable route, wherein the or each route metric is calculated in dependence upon the trust value assigned to one or more of the router or routers or link or links within each such path.

9. A router device for use in a data network, the router comprising:

storage means for storing a routing table;

a plurality of communication ports for transmitting data packets to and receiving data packets from interconnected nodes when the router is in use as part of an interconnected network or internetwork of nodes or networks; and

a processor or group of processors for calculating a metric in respect of one or more routes for the onward forwarding of received data packets and for selecting a next hop, in respect of each received data packet for onward forwarding, on the basis of the metric calculated for each route leading towards the desired destination of the data packet;

characterised in that the storage means additionally stores a trust value assigned to each of one or more other router devices within the network or links between router devices within the network; and

in that the processor or group of processors is additionally operable to take into account the trust value of one or more associated other router devices in calculating the or each metric.