9、OPTIONS消息
1)头字段填写说明
必选头域如下:
Call-id
Cseq
From
To
Max-Forwords
Via
常用可选头域:
Accept
Allow
Supported
2)消息实例
参考实例如下所示:
OPTIONS sip:user@carrier.com SIP/2.0
Via: SIP/2.0/UDP cavendish.kings.cambridge.edu.uk; branch=z0hG4bK1834
Max-Forwards: 70
To: <sip:user@proxy.carrier.com>
From: J.C. Maxwell <sip:james.maxwell@kings.cambridge.edu.uk>; tag=34
Call-ID: 9352812@cavendish.kings.cambridge.edu.uk
CSeq: 1 OPTIONS
Content-Length: 0
1)头字段填写说明
必选头域如下:
Call-id
Cseq
From
To
Max-Forwords
Via
常用可选头域:
Accept
Allow
Supported
2)消息实例
参考实例如下所示:







