No sound immediately outbound call after a call

Hello all,

as the subject said, I am having a issue.

no sound in an inmediately outbound call right after a (outbound) call, both parties cannot each other. and I have to wait for a few seconds to make that call again, and all works well.

have you faced this problema? any workaround?

btw, in my freepbx just have one SIP trunk to make and receive calls.

Thanks~

This is an issue with your firewall opening up ports.

What kind of firewall? If it has any kind of SIP ALG, turn it off.