Subject: Refresh Messages

From: [email-masked]
Date: Wed, 21 Mar 2001 15:43:36 +0100

I have read many many pages of rfc 2205, rfc 2208 and rfc 2209, 
but I could not find an answer to the following question:
Refreshes (not matter whether for Path or Resv messages) are hop 
by hop, right? That means: A router which holds an RSVP Path or 
Resv state refreshes this state, i.e. sends a refresh message to the 
next host, whenever the refresh time intervall (chosen locally 
according to rfc2205, p.56) expires. And that no matter whether it 
got a refresh message from its previous hop or not as long as the 
live time value L did not expire. 
Consider the following example: Router i chose to refresh path state 
for session s every 30 seconds. It should receive a refresh Path 
message for session s from router i-1 every 15 seconds. It didn't get 
one for more than 30 seconds, however. But L didn't expire yet. So 
will router i send a refresh message for session s to router i+1 after 
its refresh interval of 30 seconds has expired? As I do interpret 
page 56 in rfc2205 it will. Could anyone please tell me, whether I am 
right and also tell me where exactly this can be found in the rfcs?

Another issue is: Sender Se tries to estabhlish an RSVP 
connection. So it sends a Path message downstream towards 
receiver Re. Unfortunately, router i forwards this Path message, but 
it gets lost before it arrives at router i+1. It is router i who will resent 
the message after the expiration of its refresh time interval R even 
though it does not hold a corresponding Resv state and therefore 
cares about the (possibly) successful connection establishment, 
right? 

Any help will be appreciated.

Regards, R A Martin