ACK sip:1086@152.66.244.39 SIP/2.0
From: <sip:pityu@152.66.244.10>
To: <sip:1086@152.66.244.39>
Contact: <sip:pityu@152.66.244.10>
Via: SIP/2.0/UDP 152.66.244.10
Call-ID: 1111@152.66.244.10
CSeq: 1 ACK
Content-Length: 0
Max-Forwards: 70
User-Agent: EXAMPLE User Agent 1.0