Subject: RSVP-TE: ERO question

From: [email-masked]
Date: Fri, 3 Aug 2001 11:28:50 -0700

I haven't seen reference to the following in any archives, so I hope someone
can shed some light on this for me.

Section 3.1.5 of RFC2205 (RSVP V1) stipulates the following: "A PathTear
message must be routed exactly like the corresponding Path message."

Given that the RSVP-TE draft defines the EXPLICT_ROUTE object (ERO) that can
effectively circumvent the active route from any given node to the session
DestAddress and, moreover, that the ERO is applicable to the Path message
exclusively (see section 3 of the RSVP-TE draft), it follows that, if an ERO
is employed, a PathTear message may follow a different path than the
corresponding Path message.
Is this not a conflict?

Tim Jackson
Terabeam

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From: Eric Gray <[email-masked]>
Date: Fri, 03 Aug 2001 14:49:59 -0400

Tim,

    A PATH message needs to continue to carry the ERO object in
refreshing PATH messages because it has the ability to specify a
different Explicit Route over time.  This is not needed for a PATH
TEAR message, therefore it is possible to correctly propagate the
PATH TEAR using RSVP state alone.

--
Eric Gray

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From: Ray Qiu <[email-masked]>
Date: Fri, 3 Aug 2001 11:40:53 -0700 (PDT)

Tim,

I think the PathTear will take the same route, because all the routers
already have the PSBs(Path State Block) installed, they should know where
to send out the PathTear message.

Ray