[SIPForum-discussion] Why Ack is different transaction?

[Avishek Chowdhury]

Hi Aditi,

When the UAC receives 200 OK, the client transaction is destroyed at TL.
This is done because, the TL is unaware of the above core. The above core can be a Proxy or an UAC core.
In case of proxy, the 200 OK is forwarded whereas in case of UAC, an ACK is generated. Now this ACK has to create a new transaction (transaction created by INVITE had been destroyed)
at TL for its transmission, hence the ACK for 200 OK is outside the INVITE transaction.

For other non-2xx final responses, the client transaction at TL is not destroyed and the ACK is generated by TL. Hence in this case, the ACK is within the transaction.

Regards,
Avishek

  ----- Original Message ----- 
  From: aditi g 
  To: discussion at sipforum.org 
  Sent: Wednesday, March 28, 2007 9:52 AM
  Subject: [SIPForum-discussion] Why Ack is different transaction?


  Hi,

  I want to know why ACK is considered different transaction from Invite transaction .

  regs


------------------------------------------------------------------------------


  _______________________________________________
  This is the SIP Forum discussion mailing list
  TO UNSUBSCRIBE, or edit your delivery options, please visit http://sipforum.org/mailman/listinfo/discussion
  Post to the list at discussion at sipforum.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20070328/b12e1ee5/attachment-0002.html>