Granted Patent B2

US 8,018,939 · App. 11/826,220 · Granted Sep 13, 2011

Abstract

Claims (46)

1. A method for setting a timing interval between attempts to establish a label switched path (LSP) between an ingress node and an egress node of a communication network, comprising:

defining a unique identification (LSP ID) for said LSP;

establishing a signaling link between said ingress and egress nodes;

at said ingress node, monitoring said signaling link to detect a message indicating that said LSP has been established;

initiating from said ingress node a new attempt to establish said LSP after a retry time interval from a previous attempt, if said ingress node did not receive said message indicating that said LSP has been established from said signaling link;

repeating the initiating step after a different retry time interval, said different retry time interval being greater than said retry time interval; and

for each different retry time interval, incrementing a retry sequence number until a maximum retry sequence number is reached.

2. The method of claim 1 , wherein said different retry time interval is greater than said retry time interval by a fixed time value.

3. The method of claim 1 , wherein said initiating step further comprises:

providing, at said ingress node, a retry timer based on a linear back-off mechanism for enabling successive attempts to establish said LSP at increasing retry time intervals.

4. The method of claim 3 , wherein said retry timer provides T seconds between said new attempt and said previous attempt and wherein each next successive retry time interval is longer than a respective previous retry time interval by said T seconds.

5. The method of claim 1 , wherein a total retry time for all successive attempts to establish said LSP does not exceed a maximum time value.

6. The method of claim 1 , wherein said LSP is a soft permanent LSP.

7. The method of claim 4 , wherein said T seconds is ten seconds.

8. The method of claim 5 , wherein said maximum time value is sixty seconds.

9. A method for establishing label switched paths (LSPs) across a communication network, comprising;

maintaining at a first node of said communication network a list of records including all said LSPs to be established from said first node;

selecting from said list of records a first record for a particular LSP of said LSPs to be established, and establishing a first signaling link between said first node and an egress node for said particular LSP;

monitoring at said first node for messages indicating that said particular LSP has been established;

if said particular LSP has been established, marking said first record as being successful;

initiating from said first node a new attempt to establish said particular LSP after a retry time interval from a previous attempt, if said ingress node did not receive said message indicating that said particular LSP has been established from said first signaling link;

repeating said initiating step after a different retry time interval having an interval greater than said retry time interval; and

for each different retry time interval, incrementing a retry sequence number until a maximum retry sequence number is reached.

10. The method of claim 9 , wherein said initiating step further comprises:

establishing at least a second signaling link between said ingress and egress node and selecting one of said first and said second signaling links utilizing a round-robin algorithm.

11. The method of claim 10 , further comprising:

not selecting any of said first and second signaling links whenever said network does not have sufficient resources for establishing signaling links.

12. The method of claim 9 , wherein said selecting step further comprises:

providing each record in said list of records with a time field holding a respective time value;

decrementing said time value for each record in said list of records at regular intervals of time; and,

selecting said LSP when the time value in said time field for said first record reaches zero.

13. A method for setting a timing interval between attempts to establish a label switched path (LSP) between an ingress node and an egress node of a communication network, comprising:

defining a unique identification (LSP ID) for said LSP;

establishing a signaling link between said ingress and egress nodes;

at said ingress node, monitoring said signaling link to detect a message indicating that said LSP has been established;

initiating from said ingress node a new attempt to establish said LSP after a retry time interval from a previous attempt, if said ingress node did not receive said message indicating that said LSP has been established from said signaling link;

repeating the initiating step after a different retry time interval, said different retry time interval being greater than said retry time interval, wherein a total retry time for all successive attempts to establish said LSP does not exceed a maximum time value; and

for each different retry time interval, incrementing a retry sequence number until a maximum retry sequence number is reached.

14. A method for establishing label switched paths (LSPs) across a communication network, comprising:

maintaining at a first node of said communication network a list of records including all said LSPs to be established from said first node;

selecting from said list of records a first record for a particular LSP of said LSPs to be established, and establishing a first signaling link between said first node and an egress node for said particular LSP;

monitoring at said first node for messages indicating that said particular LSP has been established;

if said particular LSP has been established, marking said first record as being successful;

initiating from said first node a new attempt to establish said particular LSP after a retry time interval from a previous attempt, if said ingress node did not receive said message indicating that said particular LSP has been established from said first signaling link;

repeating said initiating step after a different retry time interval having an interval greater than said retry time interval, wherein a total retry time for all successive attempts to establish said LSP does not exceed a maximum time value; and

for each different retry time interval, incrementing a retry sequence number until a maximum retry sequence number is reached.

Assignments (10)