RE: VCn-xV LSPs terminology

["Trevor Wilson" <wilsont@nortel.com>]

Hi,

Firtsly, lets get the nomenclature correct. A virtually concatenated
signal is denoted as VC-n-Xv (please note the use of hyphens and
upper/lower case letters). Also I will use VCG = Virtually Concatenated
Group in my reply below.

Wataru: You wrote

"The VC4-7v with single RSVP session is single LSP.
 On the other hand, VC4-3v + VC4-4v with two RSVP session is two LSPs "

I assume that when you say 'VC-4-3v + VC-4-4v' you mean that the VCG has
a total of seven members transported over two routes, one with three
members and one with four members. This is and always will be a VC-4-7v.
It is not a summation of two VCGs. You cannot think of each route as a
separate VCG. The VCAT function at the terminations of the connection
will regard all individual VC-4s as members of the VC-4-7v, regardless
of which route they were transported on.

I hope this helps.

Trevor Wilson
Nortel Networks
Belfast Lab
Tel: +44 2890 363701
       ESN 751 3701
>This is the Way. This is Nortel. 
>


-----Original Message-----
From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On
Behalf Of Diego Caviglia
Sent: 27 July 2005 09:25
To: Wataru Imajuku <imajuku.wataru
Cc: Dieter Beller <D.Beller; ccamp
Subject: Re: VCn-xV LSPs terminology



Hi Wataru, Dieter,
                    yes I agree with both of you.

Regards

Diego



Wataru Imajuku <imajuku.wataru@lab.ntt.co.jp> on 27/07/2005 10.00.02

To:    Dieter Beller <D.Beller@alcatel.de>, Diego Caviglia
       <Diego.Caviglia@marconi.com>
cc:    ccamp@ops.ietf.org

Subject:    Re: VCn-xV LSPs terminology

Hi, Diego

   I understand your question is whether we shoud call LSP on the basis
of signaling session or not.

  If so, IMHO is Yes.
  The VC4-7v with single RSVP session is single LSP.
  On the other hand, VC4-3v + VC4-4v with two RSVP session is two LSPs.
  However, both of them are single LSP in the client layer as Dieter
said, .

  That is my understanding.
  But is that right, all ?

Best Regards
Wataru

>Hi Diego,
>
>Diego Caviglia wrote:
>
>>Hi all,
>>        I'd like to have a terminology clarification about virtual 
>>concatenated LSP.
>>
>>When, say a VC4-7v, VCAT circuit is set-up with a single signalling
session
>>RFC3946 (Path, Resv and may be Resv Confirm) is correct to say that 
>>the VCAT group is made by a single LSP or that is made by 7 LSPs?
>>
>>IMHO in that case there is a single LSP.
>>
>
>in my understanding, you are describing a multi-layer scenario here 
>because the VCAT client layer sits on top of the VC4 server layer (see 
>ITU-T Rec. G.806).
>
>If you are in the VCAT client layer, there is IMHO a single LSP that is

>decomposed into 7 HO VC4 LSPs in the VC4 server layer in your example.
>
>Now, if multiple (not necessarily all) VC4 LSPs are routed along the 
>same path you could set up a server layer call containing multiple VC4 
>connections using a single RSVP signaling session (as it was done in 
>the OIF interop demo this year).
>
>I hope this clarifies the issue.
>
>
>Cheers,
>Dieter
>
>--
>
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>+---------------+      Dieter Beller
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---------------------------------
Wataru Imajuku
Senior Research Engineer
@NTT Network Innovation Labs.
TEL +81-46-859-4315
FAX +81-46-859-5541