On the Mikrotik 4011 router, I have a firewall default and in the LAN network there is a telephone exchange.
Whenever I make an outgoing call, the person on the receiving end cannot hear me, while I can hear them.
Similarly, when I receive a call from somebody, I cannot hear them, while they can hear me.
It seems that the person on the receiving end of the calls cannot hear the caller.
Does anybody know what is wrong and how I can fix this?
did you turn SIP helper on/off? That’s usually the first thing to try here. I keep all conntrack helpers off so it’s less code packets need to be evaluated for which = less cpu
Make sure you have all the necessary UDP ports open to facilitate direct audio. For example with freeswitch the UDP ports for direct audio are 16384-32768. If these are not open, you end up with one way audio.
Just one reason it may be happening.
What is the overall topology? Is that PBX connected using a SIP trunk to some external exchange via internet, or are individual clients of the PBX registering to it from internet? Or even both?
I forgot to turn off the SIP helper. When turned off, it works. Thank you for your help.