The MPLS WG Archive

[Alia Atlas <aatlas@avici.com>]

At 04:34 AM 7/15/2003, Terry Lee wrote:
> But in
> section "6.1.2. Backup Path Identification: Path-Specific", it
> states :
>      Thus, the backup
> paths use the same SESSION and SENDER_TEMPLATE
>      objects as the ones used in the protected LSP.
> The presence of
>      DETOUR object in Path messages signifies a
> backup path; the
>      presence of FAST_REROUTE object and/or the
> "local protection
>      requested" flag in the SESSION_ATTRIBUTE
> object indicates a
>      protected LSP.
> It seems that the protected LSP's PATH
> message doesn't include DETOUR object. 
> On the other hand, if the head-end LSR of
> the protected LSP doesn't include DETOUR object,
> how do it control the establish the backup
> tunnels?

It uses the FAST_REROUTE object and/or the SESSION ATTRIBUTES flags to
indicate that the LSP requires local protection.  If present, then
the FAST_REROUTE object contains constraints which are applied to the
backup path selection.

Alia

-----Original Message-----

From: Alia Atlas [mailto:aatlas@avici.com]

Sent: Tuesday, July 15, 2003 3:34 AM

To: prabakarts@future.futsoft.com

Cc: 'Terry Lee'; mpls@UU.NET; 'prabakarts'

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

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.

I may have misunderstood your question earlier.  If you mean should
the DETOUR object be included in the Path message sent from the head-end
LSP for the detour LSP (as opposed to the primary LSP), then yes,
absolutely.

Alia