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Re: New draft on Extra class LSP
hi adrian, kohei,
in the case of pre-planned re-routing without extra-traffic
the unallocated protecting resource can be used by other
(lower priority LSPs) at the condition that the resources
are preempted when the working LSP fails (hint: i wanted
to point out also that this should be obvious otherwise
there is no reason for having this "path protection only")
and the below i-d points out specific aspects (that are
covered "partially" by other gmpls i-d's) see below:
- advertize the bandwidth: -> gmpls-routing (and bw acct)
- extra class LSP indication in signaling message -> priority
in (g)mpls signaling
- extra class LSP preemption signaling -> PathErr with SR
Flag and PathTear (to release the lower priority LSP)
but this can be qualified here as an "hard preemption"
mechanism
- preventing unintended connections -> it is a transient
behaviour that may occur at an intermediate node e.g.
if the previous point is not used, and cross-connection
is fully performed in the downstream direction
i see this i-d as one good reason to initiate discussion
on gmpls "soft preemption" mechanisms (and the conditions
in which the last point may occur) because the scope is
larger than p&r
thanks,
- dimitri.
Kohei Shiomoto wrote:
Hi, Adrian
In Section 9 of draft-lang-ccamp-gmpls-recovery-e2e-signaling-01.txt,
the shared mesh restoration is addressed. Extra traffic cannot be
carried because the protecting LSPs are not instantiated in shared mesh
restoration networks. But the resource for the protecting LSPs are
reserved to back up the failure of primary LSPs. The reserved resource
could be allocated for extra traffic to enhance the network utilization.
The purpose of our draft is to initiate the discussion on how to handle
extra class LSP using the reserved link resource for the protecting LSPs
while the draft-lang-ccamp-gmpls-recovery-e2e-signaling-01.txt addresses
the signaling of primary and protecting LSPs.
Regarding extra class LSP, the following issues need to be addressed:
(1) advertisement of available resource for extra class LSP, (2) extra
class LSP indication in signaling message (3) extra class LSP preemption
signaling, and (4) preventing unintended connections. Our draft provides
the problem statement of these issues.
Hope this clarify the difference.
Thank you for your interest.
---
Kohei
Shiomoto_san,
Could you help us prepare for Vienna by summarizing the difference
between
your draft and
draft-lang-ccamp-gmpls-recovery-e2e-signaling-01.txt especially with
reference to the carrying of "extra traffic" on the resources of a
protection path in a mesh network.
Thanks,
Adrian
----- Original Message -----
From: "Kohei Shiomoto" <Shiomoto.Kohei@lab.ntt.co.jp>
To: <ccamp@ops.ietf.org>
Sent: Tuesday, July 01, 2003 3:18 AM
Subject: New draft on Extra class LSP
Sorry for the incorrect subject in the previous mail. I resend it with a
new subject.
Hi, all
Please notice that a new internet-draft has been posted. The draft is
targeted at the IETF57 ccamp meeting. The draft is prepared to initiate
the discussion at the ccamp-wg on the extra class LSP service, which
makes use of reserved but unallocated bandwidth for the protecting LSPs
in the pre-planned LSP re-routing recovery method (including shared mesh
restoration). Comments and feedbacks are highly appreciated.
Thanks.
--
Kohei Shiomoto
NTT Network Innovation Laboratories
Phone +81 422 59 4402, Fax +81 422 59 6387
3-9-11 Midori, Musashino, Tokyo 180-8585, Japan
--------------------------------------------------------------------------
----------------------
Title : Extra class LSP service using protecting resources in
GMPLS networks
Author(s) : K. Shimano et al.
Filename : draft-pil-ccamp-extra-lsp-00.txt
This document provides the problem statement on a extra class LSP ser-
vice and addresses the issues. The extra class LSP uses the resource
reserved but not allocated for the protecting LSPs in the pre-planned
LSP re-routing without extra-traffic (including shared mesh) recovery
method. Network utilization is improved because the resource reserved
for the protecting LSPs are used for the extra class LSPs. The extra
class LSP is preempted less frequently than the conventional priority
mechanism using setup and holding priorities because the resource
reserved for the protecting LSPs is allocated only if the working LSP
fails, which is usually expected to rarely occur. This document pro-
poses the extra class LSP service using the resource reserved but not
allocated for the protecting LSP at the provisioning phase. This docu-
ment addresses the issues on the extra class LSP: (1) advertisement of
available resource, (2) extra class LSP indication in signaling message
(3) extra class LSP preemption signaling, and (4) preventing unintended
connections.
A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-pil-ccamp-extra-lsp-00.txt
--
Papadimitriou Dimitri
E-mail : dimitri.papadimitriou@alcatel.be
Private: http://www.rc.bel.alcatel.be/~papadimd/index.html
E-mail : dpapadimitriou@psg.com
Public : http://psg.com/~dpapadimitriou/
Address: Fr. Wellesplein 1, B-2018 Antwerpen, Belgium
Phone : +32 3 240-8491