I have been trying to do experiment with OSIP for multiple cases.
So far I am comfortable and able to send / receive couple of messages.
Now I am stuck with below scenario.
1. Party A sent INVITE to Party B.
2. On getting INVITE at Party B, it sends 183 and create a dailog as uas.
3. Party A on getting 183, creates dailog as uac and sent PRACK
4.Party B gets PRACK and sends PRACK response 200 K.
5. Party A gets PRACK response and sends UPDATE to B.