Conncet 3 asterisk server using Sip Trunk

I’m using Asterisk (Ver. on cent os.
I have 3 asterisk server A, B, C. Each work fine. Asterisk A is connected to both B and C using two Sip Trunks and it works fine too. The thing is How B can establish a call to C using sip trucks B->A than A->C.
I’ve looked everywhere but could not find answer. I’ll appreciate if anyone here tell me how?

Don’t triplicate threads. Just wait for someone to answer in the previous topics or take your issue with a consultant. In the other hand if you are using freepbx you must try in the freepbx forum.

In this case, the problem is in the “too easy” category. I think you are looking for a cook book solution, but they don’t exist because anyone who has the minimum level of understanding to use Asterisk can work out the answer for themselves. If you don’t want to get that level of understanding, you should expect to have to pay for your support.

There is basically no difference between what you are asking to do and handling an incoming direct dialing call, or even a simple outgoing call.