SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP nm;rport=26810;received=224.143.119.90;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="1712901179/9651e2ef62f75b9a334bf77784de94f4",opaque="2033d241182a2377",algorithm=md5,qop="auth"
Server: FPBX-13.0.197.31(13.17.0)
Content-Length: 0
