registering fail with ITSP

[nivanak]

1. Brekeke Product Name and version:

pbx ver2.0

2. Java version:

3. OS type and the version:

window 2000

4. UA (phone), gateway or other hardware/software involved:

5. Select your network pattern from http://www.brekeke-sip.com/bbs/network/ ... terns.html :

pattern 8

6. Your problem:

we want to register with ITSP.
but, it is fail.

my accout is

register uri : sip:1233@m1.xxx.com
proxy address : null
user : 1233
password : 1233

message is 403 ( forbidden)

but, we call out from ITSP , it is very strange..
Help me thanks.