Method and system for redundant IP forwarding in a telecommunications network

• US 7,440,394 B2
• Filed: 12/17/2004
• Issued: 10/21/2008
• Est. Priority Date: 06/24/2002
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nokia Corporation
• Inventors: Jappila, Petri, Haapala, Jukka, Patrikka, Timo, Kokkonen, Kari, Talonpoika, Pia, Ohenoja, Jussi
• Primary Examiner(s): Patel, Ajit G
• Application Number:
  US11/013,968
• Publication Number:
  US 20050099940A1
• Time in Patent Office: 1,404 Days
• Field of Search: 370/216, 370/217, 370/218, 370/219, 370/220, 714/100, 714/1, 714/2
• US Class Current: 370/216
• 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 45/586 of virtual routers

Abstract

A new feature for a network element or a router is described herein. The feature is implemented in the router as a route manager object. The first function of the feature is realized by trapping routing messages that any process like routing daemon or the route manager object sends to the input/output manager and sends them forward to an appropriate function. The second function of the feature is realized by copying the routing messages from an active unit to another instance of the route manager running in the spare unit.

Claims

1. A method, comprising:

isolating a routing daemon of a spare router from an active routing task,

blocking an access method to an internet protocol stack of said spare router,

monitoring an interval between successive routing messages,

releasing a block on said access method of said spare router after the interval between the successive routing messages exceeds a time interval,

updating routing information of a main router into said spare router, and

connecting said isolated routing daemon of said spare unit into the active routing task during a switchover from the main router to the spare router to provide redundant data forwarding in a multirouter environment.

2. The method according to claim 1, further comprising:

synchronising forwarding tables in said main router and said spare router.

3. The method according to claim 2, wherein said synchronising comprises synchronising said forwarding tables with system messages between said main router and said spare router.

4. The method according to claim 3, wherein said synchronising comprises synchronising with said system messages compressed for avoiding overhead in communication between said main router and said spare router.

5. The method according to claim 1, further comprising:

trapping all routing messages on the main router, and

copying every routing message of the main router onto the spare router.

6. The method according to claim 1, further comprising:

updating and transferring, after the block on said access method of said router has been released, a forwarding table based on routing socket messages.

7. The method according to claim 1, further comprising:

checking that there are no stale routes left hanging in internet protocol engine forwarding tables after the switchover.

8. The method according to claim 7, wherein said checking comprises removing routes that are left in a cache before the switchover but are not written to the internet protocol engine forwarding tables.

9. An apparatus, comprising:

a processor configured to;

isolate a routing daemon of a spare router from an active routing task;

update routing information of a main router into said spare router; and

connect said isolated routing daemon of said spare unit into the active routing task during a switchover from the main router to the spare router,

said apparatus further comprising;

a monitoring object configured to monitor an interval between successive routing messages; and

a blocking object configured to create a block on an access method to an internet protocol stack of said spare router and configured to release the block on said access method of said spare router after the interval between the successive routing messages exceeds a time interval to provide redundant data forwarding in a multirouter environment.

10. The apparatus according to claim 9, wherein said apparatus further comprises a synchronising object configured to synchronise forwarding tables in said main router and said spare router.

11. The apparatus according to claim 9, wherein said apparatus further comprises a compressing object configured to compress system messages in order to avoid overhead in communication between said main router and said spare router.

12. The apparatus according to claim 9, wherein said apparatus further comprises a trapping object configured to trap all routing messages on the main router, and further configured to copy every routing message of the main router onto the spare router.

13. The apparatus according to claim 12, wherein said apparatus further comprises a route cache connected to said trapping object and configured to update a route table in said apparatus.

14. A apparatus, comprising:

processing means for

isolating a routing daemon of a spare router from an active routing task;

updating routing information of a main router into said spare router; and

connecting said isolated routing daemon of said spare unit into the active routing task during a switchover from the main router to the spare router,

said apparatus further comprising;

monitoring means for monitoring an interval between successive routing messages, and

blocking means for creating a blocking on an access method to an internet protocol stack of said spare router and for releasing the block on said access method of said spare router after the interval between the successive routing messages exceeds a time interval to provide redundant data forwarding in a multirouter environment.