No voice between extensions

1. Brekeke Product Name and version:Multi Tenant

2. Java version:

3. OS type and the version:windows server

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

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

6. Your problem:When we make out side calls it is clear and when we dial extension to extension , ringing other extension but no voice both ends.
Is there any ports to be released at ISP end or at Brekeke

what is your network pattern?

http://wiki.brekeke.com/wiki/call-conne ... -no-voice-
http://wiki.brekeke.com/wiki/One-way-ca ... ice-at-all

Network pattern is pattern 8

when we dial extension to extension , ringing other extension but no voice both en

are both extensions in the same network as Brekeke pbx?