[SIPForum-discussion] Why ACK??

[Dileep Ravindran]

Thanks Every one for your valuable answers!


 I have few more doubts

1)If INVITE has 3 way handshake how come other methods like SUBSCRIBE does'nt have 3 way handshake.if we say that SDP negotiation is done using INVITE , we can also negotiate SDP in UPDATE method for which we never send ACK

2)Why a non-2XX response should have an ACK?

Thanks
Dileep 


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20100224/0a9efba7/attachment-0002.html>