Subject: [Tsvwg] Comment for the RFC-2960-bis draft.

From: Andreas Jungmaier <[email-masked]>
Date: Wed, 18 Jul 2001 18:36:10 -0400

Dear all,

I have a remark for section 6.2. of the current RFC 2960 respectively
the same section in the document draft-ietf-tsvwg-rfc2960-bis-00.txt

It says there:

 6.2  Acknowledgement on Reception of DATA Chunks

   The SCTP endpoint MUST always acknowledge the reception of each valid
   DATA chunk.

   The guidelines on delayed acknowledgement algorithm specified in
   Section 4.2 of [RFC2581] SHOULD be followed.  Specifically, an
   acknowledgement SHOULD be generated for at least every second packet
   (not every second DATA chunk) received, and SHOULD be generated
   within 200 ms of the arrival of any unacknowledged DATA chunk.

Now, it is, IMHO, not clear from that section whether that 
only applies to packets containing data chunks (as one could
think according to the section header), or it applies to
_all_ packets (well, it says "EVERY SECOND PACKET"). 

I am not sure whether it would make sense to send
a SACK after two Heartbeat chunks have been received ?!

Any comments ?

Best regards, 

Andreas Jungmaier

- ----------------------------------------------------------------------------
 \|/ _____ \|/    Andreas Jungmaier, Dipl.-Ing. 
 "@'/ , . \`@"    University of Essen           [email-masked]
 /_| \___/ |__\   -> Computer Networking        Tel. : +49 (0201) 183-7636
    \___U_/          Technology Group <-
- ----------------------------------------------------------------------------
PGP Public Key and Fingerprint: see http://www.exp-math.uni-essen.de/~ajung
- ----------------------------------------------------------------------------

_______________________________________________
tsvwg mailing list
[email-masked]
http://www1.ietf.org/mailman/listinfo/tsvwg

---

From: [email-masked]
Date: Wed, 18 Jul 2001 20:04:02 +0300

Hi Andreas,

> a SACK after two Heartbeat chunks have been received ?!

	Well, I think that it is quite clear from the title of the section,
that it is related with reception of DATA chunks... Maybe you could insert
"containing DATA chunks" right after "SHOULD be generated for at least every
second packet"... but I don't really think that's necessary at all...

	Besides, I know your question is kind of "fictitious". You know
crystal clear what it means, but just looking after (hypothetical) people
who could have this doubt, isn't it so? :-)

	In addition, having such a doubt I think that the best first option
would be going to section 4.2 of RFC 2581... There it tells you about data
segments, and there is a reference to section 4.2.3.2 of RFC 1122... Reading
this, I think that it is quite clear what it is meant in that paragraph of
RFC 2960... :-/

> Andreas Jungmaier

	BR Iván Arias Rodríguez