problems with SIP calls after proxy registration

1. Brekeke Product Name and version: Brekeke SIP Server , Version 2.4.5.5

2. Java version:

3. OS type and the version: WIN XP

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 1 All phones and PBX/SIP Server are in the same LAN.

6. Your problem: I'm having problems with SIP calls after proxy registration intermittently. Sometimes it is registered successfully with 200 Status OK and sometimes its not with 401 Unauthorized

I've packet captures for both pass and fail scenarios but I cant figure out the reason of failure....Please suggest.

Thanks!!

What kind of UA are you using?
Did you set the correct account information at the UA?

Yes, user account information is correct, because same user was able to register once

It seems phone's problem.

If you use a softphone such as X-Lite, does the same issue happen?