The MPLS WG Archive

[Alia Atlas <aatlas@avici.com>]

At 09:25 PM 7/14/2003, Terry Lee wrote:
> Thanks
> a lot.
>  
> I have another question. In section 6.4, it
> states as following : 
>  
>    6.4 Signaling for Facility
> Protection
>   
>       A PLR may use one or more bypass tunnels
> to protect against the
>       failure of a link and/or a node. 
> These bypass tunnels may be
>       setup in advance or may be dynamically
> created as new protected
>       LSPs are signaled.
>  
> My question is how to create the bypass
> tunnels dynamically? 
> how do the LSRs in the protected path know
> to be PLR and to create bypass tunnel with what attributes like
> destionation etc.

An LSR knows that it needs to determine a backup
because it is a PLR based upon the signaling of the FAST_REROUTE object
or SESSION flags.

In the same way that a PLR can dynamically create a detour which meets
its needs, a PLR could create a bypass tunnel to use instead.  This,
naturally, complicates the decision of whether to select an existing
bypass tunnel or create a new one.

Alia