REGISTERING Asterisk to Skype

Connecting * to Skippy. Can someone tell me what’s wrong with this message? I. HAVE. NO. CLUE.

REGISTER sip:sip.skype.com SIP/2.0
From: “Asterisk” sip:990510002323700@sip.skype.com;tag=8726184
To: “Asterisk” sip:990510002323700@sip.skype.com
Contact: <sip:990510002323700@ IP:PORT;rinstance=6541851>;expires=3600
Max-Forwards: 70 Via: SIP/2.0/UDP IP:PORT;rport;branch=467402
User-Agent: Mine2
CSeq: 1 REGISTER
Call-ID: 157bfc4b121bf8a55692ee33beb92ee3
Allow: ACK,BYE,CANCEL,INFO,INVITE,NOTIFY,OPTIONS,REGISTER,SUBSCRIBE,UPDATE
Content-Length: 0

IP:PORT is of course replaced when send.

And it’s not the < and > in the From: and To:, those just fell away here in the post…
Skippy says: “400 bad request”.