grandstream phones cannot communicate between each other

[cg12510]

All, I have a setup in our office something like one of others in forum has.

a central phone number 1000
have a site away from central office with 2 phones, numbers are 2000 and 2001
have a3rd site with 2 phones as well those numbers are 3000 and 3001.

phones at that site can contact the central phone with no problem (activated the audio thru PBX check box for all extensions)

when we call from 2000 to 3000 no problems, 3001 to 2001 no problems

the problem occur when we try to call 2000 to 3000 and 2001 to 3001 simultaneously, the second phone locksup and you cannot remotely get back into the phone. you can ping but cannot log into it..
Is there a setting on the phone handler that needs to selected?? we were running on the free version and upgraded to the licensed version, same problem.

we have a different system not connected to this one running on the free system and calls can be originated and received like the scenario above with no issues.

Any help would be appreciated.

Thanks

 

[leejor]

Are you using STUN on all of the remote sets? Did you set the port number on the sets at the same (remote) location so that they are not the same, i.e., one to 5060 and the second to 5061?

 

[cg12510]

Yes, we switched the setting to 5061 on both phones. same results.

 

[leejor]

Yes, we switched the setting to 5061 on both phones. same results.

You mean, on the second set at each location?

What do the 3CX logs look like when a call fails?