Restricted dissemination of topology information in a communication network
First Claim
1. A method of processing topology information at a node within a communication network, the network comprising a plurality of nodes interconnected by communication links, the node comprising a database of topology information relating to the network, the method comprising:
- receiving a topology advertisement from another node of the network which provides information about a part of the network;
comparing a metric within the newly received topology advertisement which is related to aggregate distance or cost of the path travelled by the topology advertisement with the metric of a topology advertisement previously received for the same part of the network; and
, updating the database with the newly received topology advertisement if the value of the metric in the newly received topology advertisement is lower than the metric in the topology advertisement previously received for the same part of the network.
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Abstract
A communication network comprises a plurality of nodes interconnected by communication links. A node maintains a database of topology information relating to the network. A node receives a topology advertisement from another node of the network which provides information about a part of the network. The topology advertisement includes a metric which is related to aggregate distance or cost of the path travelled by the topology advertisement. The node compares the metric in the newly received topology advertisement with one previously received for the same part of the network. The database is updated with the newly received topology advertisement if the value of the metric in the newly received topology advertisement is lower than the metric in the topology advertisement previously received for the same part of the network. The method can be used during flooding or database synchronisation. The metric can be carried within a header or body of a topology advertisement, such as a Link State Advertisement (LSA).
204 Citations
25 Claims
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1. A method of processing topology information at a node within a communication network, the network comprising a plurality of nodes interconnected by communication links, the node comprising a database of topology information relating to the network, the method comprising:
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receiving a topology advertisement from another node of the network which provides information about a part of the network;
comparing a metric within the newly received topology advertisement which is related to aggregate distance or cost of the path travelled by the topology advertisement with the metric of a topology advertisement previously received for the same part of the network; and
,updating the database with the newly received topology advertisement if the value of the metric in the newly received topology advertisement is lower than the metric in the topology advertisement previously received for the same part of the network. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A node for use as part of a communication network, the network comprising a plurality of nodes interconnected by communication links, the node comprising a database of topology information relating to the network and control logic which is operable to:
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receive a topology advertisement from another node of the network which provides information about a part of the network;
compare a metric within the newly received topology advertisement which is related to aggregate distance or cost of the path travelled by the topology advertisement with the metric of a topology advertisement previously received for the same part of the network; and
,update the database with the newly received topology advertisement if the value of the metric in the newly received topology advertisement is lower than the metric in the topology advertisement previously received for the same part of the network. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A computer program product comprising a machine readable medium carrying instructions for controlling a node of a communication network, the network comprising a plurality of nodes interconnected by communication links, the node comprising a database of topology information relating to the network, the instructions causing the node to:
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receive a topology advertisement from another node of the network which provides information about a part of the network;
compare a metric within the newly received topology advertisement which is related to aggregate distance or cost of the path travelled by the topology advertisement with the metric of a topology advertisement previously received for the same part of the network; and
,update the database with the newly received topology advertisement if the value of the metric in the newly received topology advertisement is lower than the metric in the topology advertisement previously received for the same part of the network.
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21. A signal for transmission across a communication network which carries a topology advertisement message, the message comprising a header and a body and wherein a metric indicative of the distance travelled by the message is included within the header.
- 22. A signal for transmission across a communication network which carries a topology advertisement message, the message comprising a header and a body and wherein a metric indicative of the distance travelled by the message is included within the body.
Specification