SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP nm;rport=26810;received=224.126.163.120;branch=foo
Call-ID: 50000
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=foo
CSeq: 42 OPTIONS
WWW-Authenticate: Digest realm="asterisk",nonce="1730251638/d76a605186efd4ff60b1ee122605b3b3",opaque="17b3146000de50fb",algorithm=md5,qop="auth"
Server: FPBX-13.0.197.31(13.17.0)
Content-Length: 0
