SIP/2.0 404 Not Found
From: <sip:nm@nm>;tag=root
To: <sip:nm2@nm2>;tag=b7f048-58959b40-13c4-5506-196c2a-5f2e9191-196c2a
Call-ID: 50000
CSeq: 42 OPTIONS
User-Agent: Epicentro - YAPS ADB Stack
Supported: replaces,timer,100rel
Via: SIP/2.0/UDP nm;received=224.51.188.85;rport=26810;branch=foo
Content-Length: 0

HTTP/1.1 401 Unauthorized
Server: YAPS
WWW-Authenticate: Digest realm="YapsieWorld", qop="auth", nonce="c343eff5899e3eaf225ea22c33177ead", opaque="425f662a2504e37e5338a79b87a7d854"
Content-Length: 0
Connection: close