RE: Static LSP Configuration

[Shahram Davari <Shahram_Davari@pmc-sierra.com>]

Curtis,

> -----Original Message-----
> From: Curtis Villamizar [mailto:curtis@workhorse.fictitious.org]
> Sent: Monday, May 06, 2002 4:31 PM
> To: Sudheer Dharanikota
> Cc: Gary Tam; Ajay Simha; curtis@fictitious.org; Ron Bonica; Brijesh
> Kumar; 'Curtis Villamizar '; mpls@UU.NET; CCAMP WG
> Subject: Re: Static LSP Configuration 
> 
> 
> 
> 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).


What mechanism will they use to detect the failure then?

-Shahram

  MPLS restoration needs to
> work quite well to do this and still meet SLAs and carrying L2 service
> is even more demanding.
> 
> Curtis
>