Someone

SipClient: Received: 18:36:26.599
---------------------------------
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 192.168.0.20;branch=z9hG4bK27336C0C
From: "Stephan Wienczny" <sip:stephan@hafen>
To: "Stephan Wienczny" <sip:stephan@hafen>
Call-ID: 1298161602@192.168.0.20
CSeq: 6936 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER
Contact: <sip:stephan@192.168.0.1>
Content-Length: 0


SipClient: Receiving message...

SipClient: Received: 18:36:26.604
---------------------------------
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 192.168.0.20;branch=z9hG4bK27336C0C
From: "Stephan Wienczny" <sip:stephan@hafen>
To: "Stephan Wienczny" <sip:stephan@hafen>;tag=as66799ae4
Call-ID: 1298161602@192.168.0.20
CSeq: 6936 REGISTER
User-Agent: Asterisk PBX
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER
Contact: <sip:stephan@192.168.0.1>
WWW-Authenticate: Digest realm="asterisk", nonce="62f9c54d"
Content-Length: 0