Subject: When is the heartbeat resumed after data sending is stopped?

From: [email-masked]
Date: Mon, 18 Nov 2002 12:20:33 -0500

Hi List,

On P93 in RFC 2960,

   A destination transport address is considered "idle" if no new chunk
   which can be used for updating path RTT (usually including first
   transmission DATA, INIT, COOKIE ECHO, HEARTBEAT etc.) and no
   HEARTBEAT has been sent to it within the current heartbeat period of
   that address.  This applies to both active and inactive destination
   addresses.

Based on the RFC, the heartbeat will be resumed when the dest is declared
as "idle" destination. It means that a heartbeat will be sent within the
current heartbeat period of that address after the last data is sent. Is it
right?

Thanks in advance.

Simon
RadiSys Corporation

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From: "Randall Stewart (cisco)" <[email-masked]>
Date: Tue, 19 Nov 2002 09:07:24 -0600

Simon:

What you basically do is keep track of the last time you sent to
any address of your peer. Periodically you wake up (the HB interval) and
see if you have not sent anything (data) within the last RTO).. if not you
go ahead and send a HB .. otherwise you restart your HB timer and try
again... next interval.

There is also one modification you can do to this algorithm (which I know
I did).. which is have ONLY one HB timer (not one for each link)... in this
case when you wake up it is not just one destination you look at.. but 
all destinations.. and
you take the one that has the most ammount of time past since it was 
sent to...

This then means on a completly idle association you would round robin 
your HB every
HB interval (plus the jitter and RTO) to the destinations...

R

-- 
Randall R. Stewart
ITD
Cisco Systems Inc.
[email-masked] 815-342-5222(cell) or 815-477-2127(office)