比如这样的
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OPTIONS sip:nm SIP/2.0
5 u0 d3 e7 ]) J5 G/ l! |Via: SIP/2.0/TCP nm;branch=foo4 H5 I5 G2 \" e. E
From: <sip:nm@nm>;tag=root
' _+ ?/ ^1 ^5 h/ G+ ]8 S+ STo: <sip:nm2@nm2>/ U/ a/ n! K1 `, o1 |, ?
Call-ID: 50000
- n, b _& g* ~, [CSeq: 42 OPTIONS
_/ {/ |$ `- h d: ZMax-Forwards: 700 _, k3 }. w* y( a8 \
Content-Length: 0
/ u% W4 I5 ?8 e2 VContact: <sip:nm@nm>
3 Q) U7 z/ k q( V# ]# ^Accept: application/sdp+ \6 n/ p6 q& W
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