SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 80.11.86.76:5060
To:sip:jack@atosc.org
From: <sip:jack@atosc.org>;tag=75bd3
Call-ID: 975799879@80.11.86.76
CSeq: 1 REGISTER
Supported: com.salut.amoi,100rel
Content-Length: 0
Server:  IMS1.0
WWW-Authenticate: Digest realm="This is test realm",nonce="MTAwODc4ODQzNDIzMWI2MDY0OTBlNGJjMjJkZWNiMWRmOGUwNmIwMDVlMjZl",stale=false,algorithm=MD5,qop="auth,auth-int"