Subject: Re: RSVP protocol

From: [email-masked]
Date: Sun, 17 Sep 2000 08:41:12 EDT

Hello Berson,

Thanks very much for your reply. I am sorry if my wording is not clear.

Pl. refer to the Section 2.3 of RFC 2205 where it is stated that,

      RSVP takes a "soft state" approach to managing the reservation
      state in routers and hosts.  RSVP soft state is created and
      periodically refreshed by Path and Resv messages.  The state is
      deleted if no matching refresh messages arrive before the
      expiration of a "cleanup timeout" interval.

By this I understand since it is explicitly stated above that the state is 
deleted if no matching refresh messages arrive before the expiration ...

Further, I wish to say that I am now involved in testing an implementation 
which sends path & resv refresh messages and occasionally I see a resv 
refresh going on the network for no path message. Now, my doubt is whether 
this is correct. According to what you say it is correct.

I am sorry to trouble you but for me still the RFC is not clear. Let me know 
if I miss something.

Thanks
Ram

---

From: David Charlap <[email-masked]>
Date: Mon, 18 Sep 2000 10:24:15 -0400

[email-masked] wrote:
> 
> 
> Further, I wish to say that I am now involved in testing an
> implementation which sends path & resv refresh messages and
> occasionally I see a resv refresh going on the network for no path
> message. Now, my doubt is whether this is correct. According to what
> you say it is correct.

A Resv message is legal at any time, as long as its session exists on
the switch that receives the message.  If the Resv message is identical
to a previously-sent Resv message, then it is a refresh.  If it is
different, then it may cause state changes in the Phop router, which may
result in it changing the Resv message that it sends out.

-- David