Client Request:
=========================
CANCEL q4s://www.example.com Q4S/1.0
User-Agent: q4s-ua-experimental-1.0
Session-Id: 53655765
Content-Type: application/sdp
Content-Length: 142

(SDP not shown)
=========================

Server Request in reaction to Client Request:
=========================
CANCEL q4s://www.example.com Q4S/1.0
Session-Id: 53655765
Expires: 0
Content-Type: application/sdp
Signature: 6ec1ba40e2adf2d783de530ae254acd4f3477ac4
Content-Length: 131

(SDP not shown)
=========================