The MPLS WG Archive

["abhay" <abhay@multitech.co.in>]

Hi,

 

For backup LSP to do fast re-routing consider the following steps:

 

1) Store the List of nodes the primary path is traversing

 

Now you may need complete protection of the primary path or partial protection:

 

In case of Partial protection:

 

1) Exclude the set of routers which you may feel as a Network administrator are prone to link failures and apply the input to CSPF algorithm

 

Signal the protection path from the new ingress to egress,which does not include the excluded routers.

 

In case of Complete Path protection:

 

1) Each next hop needs to be excluded,how u are going to do it,is to maintain additional state information along the primary path and also some

interaction with signaling protocols.

 

2) For the complete path protection,CSPF algorithm may be applied at each alternate router with the constraint to exclude the next hop.

 

Hope this helps,

Regards,

Abhay

 

Abhay D.S

Senior Software Engineer,

Multitech Software Systems,

Bangalore-95

India

 

----- Original Message -----

From: Charlotte Hullo

To: mpls@UU.NET

Sent: Wednesday, March 27, 2002 6:55 PM

Subject: Backup LSP computation

Which algorithm is used to compute the backup LSP to do fast rerouting in case of link or router failure?