asterisk users - Jun 2004 - SIP Registration with Entice Softswitch

I'm having problems getting Asterisk SIP to register with an Entice
softswitch SIP Gateway. My provider tells me that all thats needed is a
user name, password and the IP address and to register and it needs to
be using MD5 authentication.

I continualy get a "603 Decline" message. The provider of the gateway
says they are not receiving any authentication information. Registration
using Sipura SPA2000 works fine and so does X-Lite but not Asterisk.

I know and have tested to see that its not a NAT problem. I have
successfully registered to Asterisk all my sip phones and to FWD.

I'm baffled as to why no authentication information will come up in the
SIP debug. It seems to me to be a problem with the Entice gateway but
need to be certain.

I have included the SIP Debug from Asterisk and part of my sip.conf file

Any ideas on how to get this to work will be greatly appreciated.

Norman Howlett - norman@em-tech.com.au

# SIP Debug #

11 headers, 0 lines
Reliably Transmitting:
REGISTER sip:202.168.7.33 SIP/2.0
Via: SIP/2.0/UDP 192.168.1.2:5060;branch=z9hG4bK7039010e
From: <sip:username@202.168.7.33>;tag=as537ee02c
To: <sip:username@202.168.7.33>
Call-ID: 6b8b4567327b23c6643c986966334873@192.168.1.2
CSeq: 103 REGISTER
User-Agent: Asterisk PBX
Expires: 120
Contact: <sip:s@192.168.1.2>
Event: registration
Content-Length: 0

 (no NAT) to 202.168.7.33:5060

Sip read:
SIP/2.0 100 Trying
Via: SIP/2.0/UDP
192.168.1.2:5060;rport=1024;received=203.173.22.53;branch=z9hG4bK7039010e
To: <sip:username@202.168.7.33>
From: <sip:username@202.168.7.33>;tag=as537ee02c
Call-ID: 6b8b4567327b23c6643c986966334873@192.168.1.2
CSeq: 103 REGISTER
User-Agent: Entice 1.7  Build 2
Content-Length: 0
                                                                          8
headers, 0 lines
                                                      
Sip read:
SIP/2.0 603 Decline
Via: SIP/2.0/UDP
192.168.1.2:5060;rport=1024;received=203.173.22.53;branch=z9hG4bK7039010e
To:  <sip:username@202.168.7.33>;tag=ff0035f1-00483
From:  <sip:username@202.168.7.33>;tag=as537ee02c
Call-ID: 6b8b4567327b23c6643c986966334873@192.168.1.2
CSeq: 103 REGISTER
Contact: <sip:username@202.168.7.33>
User-Agent: Entice 1.7  Build 2
Content-Length: 0

sip.conf file (edited for length)

[general]
context=default			; Default context for incoming calls
realm=em-tech.com.au		; Realm for digest authentication

register => username:password@202.168.7.33