Subject: Inconsistent handling of INIT ACK in case of invalid parameter values

From: [email-masked]
Date: Wed, 11 Dec 2002 17:07:11 -0500

Hi List,

On Page 53 in RFC 2960, the last paragraph is:

   If an endpoint receives an INIT, INIT ACK, or COOKIE ECHO chunk but
   decides not to establish the new association due to missing mandatory
   parameters in the received INIT or INIT ACK, invalid parameter
   values, or lack of local resources, it MUST respond with an ABORT
   chunk.

However, in section 2.22.2 in draft-ietf-tsvwg-sctpimpguide-07.txt,

         If the value of the Initiate Tag in a received INIT ACK chunk is
         found to be 0, the receiver MUST destroy the association
discarding
         its TCB. The receiver MAY send an ABORT for debugging purpose.

I think that, to be consistent,  change is necessary to handle INIT ACK on
page 53 in case of invalid parameter values, etc. MAY instead of MUST
should be used for INIT ACK.

Simon

---

From: "Randall Stewart (cisco)" <[email-masked]>
Date: Thu, 12 Dec 2002 08:04:43 -0600

>   values, or lack of local resources, it MUST respond with an ABORT
Hmm.. ok the above wording is in the "normal" establishment context.. this
basically says you (the receiver of an association) have the right to
recognize you are out of resources and send an abort.... this make sense :>

>should be used for INIT ACK.
No, I don't think so... in the case above you are talking about normal 
association
procedures, no one as done anything wrong and you decide .. hey I have no
resources for this association. In the 2.22.x case we are dealing with a
INIT-ACK has arrived in response to my INIT.. however my "tenative peer" 
that
I want to bring up an association with does something illegal... aka 
sets the TAG
value in the INIT-ACK to 0. Now if you send back an abort what good does 
it do?
There is no TCB in the sender of the INIT-ACK... has pointed out in previous
list discussion the ABORT may help in debugging purposes but it does NOTHING
as far as getting rid of state ..

This is why the change makes it a MAY and I don't see that a normal 
association
establishment is equivilant to where someone discovers it is out of 
resources...

R

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