[Serusers] How to Register..?

[Santosh Subramanian, Noida]

Hi,
I have a client program , which will send REGISTER request to the proxy
server and
get back the response either "200 ok" or "401 unauthorized". 
I'm running SER proxy server in my local network and it is giving me "401
unauthorized".
no problem in that.

Now I'm trying to contact iptel.org with that program. Its since I'm running
my program 
behind the firewall, the address and port (195.37.77.101:5060) is opened for
me both ways.
So my request should have reached iptel.org. Problem is, no response from
iptel.org. 

can anyone working behind firewall send me the message format for REGISTER
request.
I've attached mine along with this mail.. kindly let me know if anything is
wrong.
I'm not able to proceed from this point.

Kind Regards,
Santhosh.S

My Register Request:
=====================
REGISTER sip:san.iptel.org:5060 SIP/2.0
Via: SIP/2.0/UDP 192.168.14.56:5060;branch=z9hG4bK2952839661;rport
From: san <sip:san at iptel.org>;tag=946143070
To: san <sip:san at iptel.org>
Call-ID: 320799555 at 195.37.77.101
CSeq: 1 REGISTER
Contact: san <sip:san at 192.168.14.56:5060>
max-forwards: 70
user-agent: oSIP-ua/0.8.1
expires: 3600
Content-Length: 0

where username is "san"

My call flow shld. be:

   san                        SER Sip Server 
     |                               | 
     |          REGISTER F1          | 
     |------------------------------>| 
     |      401 Unauthorized F2      | 
     |<------------------------------| 
     |          REGISTER F3          | 
     |------------------------------>| 
     |            200 OK F4          | 
     |<------------------------------| 
     |                               |