Subject: Cookie echo when TCB exists

From: [email-masked]
Date: Thu, 4 Sep 2003 15:16:10 +0530

Hi,

The section 29 of the SCTP Implementer's Guide clarifies:

"When both local and remote tags match the endpoint should
enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
It should stop any cookie timer that may be running and send
a COOKIE ACK"

What is still not clear is when should an implementation respond back with
a cookie ack. Should it send a cookie ack only when it was in cookie-echoed
state? But it could be the case that cookie ack sent earlier was dropped by
the network and this is cookie echo retransmitted by the peer, in which
case a cookie ack must be sent even if the current state is established.
What should an implementation do if it receives such a cookie echo while
shutdown is in progress. Should it reply back with a cookie ack or a
shutdown ack or silently discard the packet?

regards
Manish
www.hssworld.com

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From: "Lei Zhang" <[email-masked]>
Date: Thu, 4 Sep 2003 12:24:20 +0200

Hi, Manish

the book "Stream Control Transmission Protocol (SCTP)" by Stewart and Xie has an explanation about "a lost COOKIE-ACK" on page 121. 

Regards

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
Sent: Thursday, September 04, 2003 11:46 AM
To: [email-masked]
Subject: Cookie echo when TCB exists

Hi,

regards
Manish
www.hssworld.com