EP0348331A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of efficiently updating the topology databases of the nodes in a data communications network
Assignee: International Business Machines Corp
•
Filing: 1989-06-07
•
Granted: —
•
Expires: 2009-06-07
Abstract
Abstract In a communications network, each network node can maintain its own list of network resources in a topology database. When the state of a resource "owned" by a particular node changes, that node broadcasts a topology database update (TDU) message to adjacent nodes. Each adjacent node updates its own topology database and rebroadcasts the message. To minimize the amount of information that must be included in TDU messages when two nodes are reconnected after an outage, each node assigns flow reduction sequence numbers (FRSNs) to TDU messages and keeps a record of the FRSN for the last TDU message sent to an adjacent node. The node also records, for each resource in its database, the FRSN of the last TDU message including that resource. When two nodes are reconnected, the sending node includes in the TDU message only those resources having a FRSN greater than the FRSN assigned to the last TDU sent to the adjacent node to which the TDU message is directed.
Inventors
- 👤 Andrew Hilliard Arrowood
- 👤 Kathryn E. Clarke
- 👤 John Ellis Drake, Jr.
- 👤 John Lawrence Eisenbies
- 👤 James Peyton Gray
- 👤 Karla Jean Norsworthy
- 👤 Diane Phylis Pozefsky
- 👤 Terence Dale Smetanka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 17:09
CPC Classifications
H; H04; H04L; H04L41/00; H04L41/12; H04L45/00; H04L45/02; H04L45/021
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
188 words
Method of efficiently updating the topology database at each network node in a communications network wherein the node maintains a topology database comprising individual records defining individual network resources by exchanging topology database update messages with adjacent nodes, each of said messages containing information about at least one network resource defined in the topology database of the sending node; said method being characterized by the following steps: assigning a unique sequence number to each topology database update message generated by the sending node; maintaining a record of the sequence number of the most recent topology database update message sent to each adjacent node and, for each individual resource defined in the topology database, the sequence number of the most recent topology database update message including that resource; and including in any topology database message sent to an adjacent node only those resources having a recorded sequence number greater than the sequence number of the most recent topology database update message previously sent to that node, whereby the amount of information that must be sent to adjacent nodes to update the topology databases stored at these nodes is reduced.
Claim 2
Dependent Claim
188 words
Method of efficiently updating the topology database at each network node in a communications network wherein the node maintains a topology database comprising individual records defining individual network resources by exchanging topology database update messages with adjacent nodes, each of said messages containing information about at least one network resource defined in the topology database of the sending node; said method being characterized by the following steps: assigning a unique sequence number to each topology database update message generated by the sending node; maintaining a record of the sequence number of the most recent topology database update message sent to each adjacent node and, for each individual resource defined in the topology database, the sequence number of the most recent topology database update message including that resource; and including in any topology database message sent to an adjacent node only those resources having a recorded sequence number greater than the sequence number of the most recent topology database update message previously sent to that node, whereby the amount of information that must be sent to adjacent nodes to update the topology databases stored at these nodes is reduced.
Claim 3
Dependent Claim
65 words
The method according to claim 1 further comprising , upon establishment of a connection with an adjacent node, the steps of receiving, from said adjacent node, the sequence number of the most recent topology database update message actually received by that node, and comparing the sequence number received from that node with the sequence numbers assigned to the individual resources defined in the topology database.
Claim 4
Dependent Claim
88 words
The method as defined in Claim 2 wherein the node receiving a topology database update message processes that message by: retrieving the sequence number of the most recent topology database message previously received from the node sending the current topology database update message; comparing the sequence number assigned to the current topology database update message to the retrieved sequence number; and updating the topology database utilizing the current topology database update message only where the sequence number assigned to that message is greater than the retrieved sequence number.
Claim 5
Dependent Claim
57 words
The method according to claim 1 further comprising, upon establishment of a need to send a topology database update message to adjacent nodes, the step of comparing the sequence number of the most recent topology database update message previously sent to each node with the sequence numbers assigned to the individual resources defined in the topology database.
Claim 6
Dependent Claim
87 words
The method as defined in Claim 4 wherein the node receiving a topology database update message processes that message by: retrieving the sequence number of the most recent topology database message received from the node sending the current topology database update message, comparing the sequence number assigned to the current topology database update message to the retrieved sequence number, and updating the topology database utilizing the current topology database update message only where the sequence number assigned to that message is greater than the retrieved sequence number.
Claim 7
Dependent Claim
39 words
The method as defined in Claim 5 further including the steps of: discarding without use any received topology database update message not having a sequence number greater than the retrieved sequence number; and terminating the connection between the nodes.
Claim 8
Dependent Claim
145 words
The method according to claim 1 further comprising upon establishment of a connection between two nodes; the steps of: causing a first of said nodes to send a request for a topology database update message to the second of said nodes, said request containing the sequence number of the most recent topology database update message previously received from the second node or a unique sequence number if no topology database update messages have been received from the second node, causing the second of said nodes to respond either with a topology database update message including only individual records for network resources having recorded sequence numbers greater than the sequence number received from said first node or, if the unique sequence number was received, with a topology database update message including the individual records for all network resources in the topology database of said second node.
Claim 9
Dependent Claim
74 words
The method as defined in Claim 7 wherein said first node: maintains a record of the sequence number of the most recent topology database message received from said second node; and updates the topology database utilizing a topology database update message received from said second node only where the sequence number of said message is greater than the recorded sequence number for the most recent topology database message previously received from said second node.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.