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questions about draft-ietf-mpls-rsvp-lsp-fastreroute-02.txt

  • From: "Prabakaran T Sampath" <prabakarts@future.futsoft.com>
  • Date: Mon, 14 Jul 2003 22:02:46 +0530
  • Cc: "'prabakarts'" <prabakarts@future.futsoft.com>
  • Importance: Normal

Hi Terry Lee,
 
Please find my in lined comments [PrabakarTS].
 
Thanks and regards,
Prabakaran T.S.
Future Software Limited,
480-481, Anna Salai,
Chennai - 600035, India.
Off Phone: +91-44-24330550 - Extn: 319
-----------------------------------------------------------
-----Original Message-----
From: owner-mpls@uu.net [mailto:owner-mpls@uu.net]On Behalf Of Terry Lee
Sent: Monday, 14 July 2003 11:43 AM
To: 'mpls@uu.net'
Cc: Terry Lee
Subject: questions about draft-ietf-mpls-rsvp-lsp-fastreroute-02.txt

1.       DETOUR object’s Class is TBD, Why?

[PrabakarTS]  In section 4.2 of the draft, the class value is specified to be of

Class = TBD  (to conform 0bbbbbbb format for compatibility)  It meant that the Class value

is not yet assigned and time being we can use the "0bbbbbbb" format as specified in

RFC 2205 section 3.10 for backward compatibility.  So that,

 

The high-order bit of the C-Class is zero; LSRs that do not support

the DETOUR objects MUST reject any Path message containing a DETOUR

object and send a PathErr to notify the PLR.  This PathErr SHOULD

be generated as specified in [RSVP] for unknown objects with a

class-num of the form "0bbbbbbb". 

 

So, time being(until draft finalizes the Class value) it is upto the implementation specific to

assign some unique Class value of the form "0bbbbbbb" for this DETOUR Object Class.

 

The similar answer is applicable for FAST_REROUTE Object

of its Class = TBD  (use form 11bbbbbb for compatibility)

 

2.       should DETOUR object be contained in the head-end LSR in one-by-one technique? I think the answer is yes.
[PrabakarTS]  Yes, you are correct.

3.       in facility technique, a backup tunnel can protected many LSP. Say LSP1and LSP2 in different SESSION. What

the FRR backup tunnel’s SESSION should be?

In draft-ietf-mpls-rsvp-lsp-fastreroute-02.txt:

Thus, the only field in the SESSION and SENDER_TEMPLATE objects which could be varied between

a backup path and a protected LSP is the "IPv4 (or IPv6) tunnel sender address" in the SENDER_TEMPLATE.
[PrabakarTS] IPv4 tunnel Sender address in SENDER_TEMPLATE will be used to identify the Backup path

in the Sender-Template-Specific Backup path Identification approach at the PLR.  The PLR should put its

IPv4 tunnel Sender address in SENDER_TEMPLATE. Whereas in Path-Specific - Backup path Identification

approach the DETOUR object, is used to distinguish between PATH messages for a backup path and the
protected LSP.