SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP nm;rport=26810;received=224.148.40.44;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="1717936664/b0c873638871bd11d401f9a3eb9e4f67",opaque="76be44bb7838d016",algorithm=md5,qop="auth"
Server: FPBX-16.0.40.7(18.6.0)
Content-Length: 0
