Cannot setup call between two subscribers.

1. Brekeke Product Name and version:

2. Java version:

3. OS type and the version:

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: I installed Brekeke PBX. I have three users
(say A,B, and C)created and registered to SIP Server. Now I want
to call B or C from A but I always get 486 from the proxy. But if I
put C's number in B's forward text box then C will receive the
call from A and can answer the call. Can any body tell me why
can I just make a simple call between two subscribers?

which version of pbx are you using?
are all of three users registered to sip server?
Are there pbx users created for three users A, B and C?
can call be made between B and C?