Re: Static LSP Configuration

[Curtis Villamizar <curtis@workhorse.fictitious.org>]

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In message <3CD6C43C.94BACCEE@nayna.com>, Sudheer Dharanikota writes:
> 
> Transport networks are *built* to provide 50 msec recovery
> times (e.g., rings, span, 1+1 etc). Hence a failures are scoped to be
> within a domain (typically a ring or a span or in the worst case
> end-to-end[1+1 case]).  Excluding failure detection time in this
> 50 msec (taking from SONET knowledge), failure reporting
> and recovery should take 50 msec. Obviously this cannot
>  be done with OSS intervention. One can use SONET's
> inband signaling mechanisms for failure reporting or use
> *directed notification* mechanisms such as the ones proposed
> for signaling protocols. Note that if we assume a ring topology then
> the messages are only one hop away (with the assumption that
> only the DCS are the intelligent devices). So your worry of 5-10
> hop path is not valid in my opinion.
> 
> Regards,
> 
> sudheer


The discussion was about MPLS but an underlying assumption seemded to
enter into the thread with that last email that either APS was running
under MPLS or L2 was the application and APS was running over MPLS
provided over multiple end to end L2 tunnels.

I don't know of anyone doing SONET APS over the L2 tunnels of an MPLS
backbone.

I do know of providers who want to eliminate the APS on the sonet
links under their MPLS network cutting some costs significantly (but
with all things considered, not in half).  MPLS restoration needs to
work quite well to do this and still meet SLAs and carrying L2 service
is even more demanding.

Curtis