RE: Basic doubts on 1:1 path protection signaling.

["Balasubramania N. Pillai" <bpillai@lopsys.com>]

Thanks Dimitri and John for trying to help me.

Thanks for the detailed reply. I am clear on the first two questions. But I
am still a little bit confused with my third question. May be I didn't
understand the concept right. So let me try again.

I was most confused with how do we do signaling to setup the "Extra Traffic"
LSP. Are you suggesting that there is not additional signaling to setup the
"Extra Traffic LSP". Setup the protection LSP along with the working LSP. At
this point the two LSP are setup and the user is free to use the protection
LSP to carry extra traffic.

My confusion is around this issue. Once the protection LSP is setup, do we
need to do extra signaling to setup the "Extra Traffic LSP" on top of the
protection LSP.


Thanks in advance for you help.

Balu




-----Original Message-----
From: Dimitri.Papadimitriou@alcatel.be
[mailto:Dimitri.Papadimitriou@alcatel.be]
Sent: Tuesday, April 27, 2004 3:13 AM
To: Balasubramania N. Pillai
Cc: 'ccamp@ops.ietf.org'
Subject: Re: Basic doubts on 1:1 path protection signaling.




Balasubramania N. Pillai wrote:
> Hi All,
> 
> I was reading the draft-ietf-ccamp-gmpls-recovery-e2e-signaling-00.txt and
I
> have some basic doubts regarding signaling 1:1 protected LSP with extra
> traffic.
> 
> 
> 1. My understanding is that Section 7 talks about 1:1 Protection (the
> protection path is fully setup and cross-connects are made) and not 1:1
> Restoration (no cross-connects for protection path)

as the title indicates and explained in the text

> 2. Since the protection LSP is setup (cross-connected), I guess we should
> advertise that the resources used by the Protection LSP as "in use" in
> routing.

if it is cross-connected it is "in use"

> 3. Section 7, Paragraph 3 says that
> 
> 	Although the resources for the protecting LSP are pre-allocated,
> 	preemptable traffic may be carried end-to-end using this LSP (i.e.
> 	the protecting LSP is capable of carrying extra-traffic) with the
> 	caveat that this traffic will be preempted if the working LSP fails.
> 
> Take the case where a 1:1 LSP is setup. Both the working LSP and the
> protection LSP are setup and cross-connected. Now if we want to add a
> extra-traffic, how do we signal, to setup the LSP carrying the Extra
> traffic. 

the protecting lsp allows carrying extra-traffic (in a sense you may see 
for the 1:1 protection case, the protecting lsp as the "extra-traffic 
lsp" but this terminology is misleading reason why it is not used)

> What objects do we use to associate the "Extra Traffic LSP" to the
> protection LSP.

the association object is used to bind the protected and the protecting lsp

hope this clarifies (note: an update is being prepared to further 
clarify some of the comments made on the list)

thanks,
- dimitri
> Thanks for you time
> 
> Balu
> 
> 
> 
> 

-- 
Papadimitriou Dimitri
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