The MPLS WG Archive

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

> > 1, 2, 4, 5 haven't been answered.
> 
> 4 and 5 were deferred.

Thanks got the answers.

> 
> > > > 1) In L2VPN or L3VPN do we need to push both inner and 
> outer label?
> > > > if not then do people agree to add the inner label to 
> the FEC TLV?
> > > 
> > > Depends on which LSP you are testing.  Is the inner label 
> semirandom
> > > payload to exercise load split or is it the LSP actually 
> under test.
> > 
> > I want to test the inner LSP. Do I need to push both 
> labels? or only the
> > transport label? In case I push both labels there is no way 
> to detect
> > the ping packet at the egress. So my suggestion was to only push
> > the top label and add the inner label to the echo-request.
> > (This point was also raised by Eric Rosen)
> 
> My interpretation is push both labels.  Both start at TTL=1.
> Increment top, then next label.  If they both terminate at the same
> egress LSR (normal for BGP VPN) then bottom TTL never gets past 1.

What do you do for pinging the inner LSP?


> 
> > > > 2) How do we return the label mapping TLV in case 
> RSVP-TE is used
> > > > for the return path? (no such object is defined for RSVP-TE)
> > > 
> > > According to the instructions in section 5.  Use the 
> RESV.  Add the
> > > object specified in the doc.  What's not clear?
> > 
> > Section 3.2 describes something called Downstream Mapping TLV. This
> > is defined for IP packets only. When the return path is the RSVP-TE,
> > how does the downstream mapping gets encoded in RESV 
> message? May be the
> > answer is trace-route has no value when the return path is 
> RSVP-TE ! or
> > may be a Downstream mapping Object needs to be defined.
> 
> Downstream is in the forward direction so this question doesn't make
> sense.
> 
> The Downstream Mapping TLV never refers to the return path.

Check the last paragraph of section 4.3:


   If the echo request contains a Downstream Mapping TLV, the replier
   SHOULD compute its downstream routers and corresponding labels for
   the incoming label, and add Downstream Mapping TLVs for each one to
   the echo reply it sends back.

-Shahram


> 
> <snip to end - 4&5 in another message>
> 
> Curtis
>