INVITE packet Incompatibility

I have a softswitch (172.28.0.133) and encountering problem with Asterisk peering partner. The Asterisk could not make call through to my Softswitch.

When the asterisk send a request to softswitch, the call is not going through. When i captured the ethereal, i found there is UserID appearing in “From” of the INVITE packet, i.e, 12345@172.28.0.133.

Can we configure to get rid off the 12345@ so that the asterisk only send the IP address, i.e. 172.28.0.133 to my SoftSwitch?

For your kind information, this Asterisk peering partner only using SIP protocol to send calls.

Please help.

Thanks.