Subject: OSPF RSVP...

From: "[email-masked]" <[email-masked]>
Date: Wed, 12 Mar 2003 21:10:31 +0100

Hi all,
essentially my considerations are: if i have two pre-calculated disjoint backup paths and i use opaque LSA to flood the link failure information,
it could be a reasonable faster  way of proceeding instead of using RSVP if i have an intelligence in the source routers (routers have to be able to switch among the two LSPs if they receive that particular opaque LSA; note that for a restoration of many LSPs RSVP will work in series, but OSPF will work in parallel with its flooding mechanism).
So the basic question is: is it a reasonable way the use of OSPF  and opaque LSA? Is there a reason to the use always RSVP for path protection, since, i think, increasing the LSPs corrupted by one link failure (if there are many active LSPs on the link that goes down) the OSPF mechanism of flooding is more efficient than using many RSVP messages from node that detects the failure towards the LSPs senders?

Thanks in advance for your kind answers and observations.

Giovanni Di Giacomo

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From: alok <[email-masked]>
Date: Fri, 14 Mar 2003 14:32:15 +0530

> Hi all,
> essentially my considerations are: if i have two pre-calculated disjoint
backup paths and i use opaque LSA to flood the link failure information,
> it could be a reasonable faster  way of proceeding instead of using RSVP
if i have an intelligence in the source routers (routers have to be able to
switch among the two LSPs if they receive that particular opaque LSA; note
that for a restoration of many LSPs RSVP will work in series, but OSPF will
work in parallel with its flooding mechanism).

but doesnt that "serial thingy" reduce your traffic? with flooding,you are
increasing the same....why do you need to telll everyone somethig that only
few people need to know?

......and eitherways for all new LSPs being setup the IGP is anyway flooding
and telling the adjacencies about the link status...

> So the basic question is: is it a reasonable way the use of OSPF  and
opaque LSA? Is there a reason to the use always RSVP for path protection,
since, i think, increasing the LSPs corrupted by one link failure (if there
are many active LSPs on the link that goes down) the OSPF mechanism of
flooding is more efficient than using many RSVP messages from node that
detects the failure towards the LSPs senders?

hmmm
am not too sure but i think RSVP can signal multiple "path tears" to its
adjacent nodes in the same message..so you would get the same result in a
way?..correct?
(i may be wrong about this part......)