here is my arch:
phones <> UCM (switch mode) <> router (MicroTik) <> INTERNET <> router <> phones
On my UCM side:
Outside extensions have NAT activated.
On SIP > NAT settings; SDP is activated, and external host has my Static WAN IP.
SIP port is 51064 it’s opened on router
RTP ports are 10000 to 2000, also opened on router
On my external site:
They have Static WAN IP.
Phones register to SIP just ok.
Inbound calls and outbound calls, work
Everytime they only get incoming audio, they never send out audio.
RTP and SIP ports are opened on router.
Packet capture on phone, shows that the phone recieves UDP-RTP Packets from UCM WAN IP, but they do not send any UDP or RTP packets to router or UCM WAN IP. They only recieve SIP Packets. The same with a packet capture form the UCM, I can see how the UCM sends out RTP packets and send and recieves SIP/SDP packets, but no RTP packets comes from the WAN IP of my external phones.
Phones are setup like:
SIP Server: UCM WAN IP + Port
On Accounts > SIP Settings > Custom SIP Headers: Use X-Grandstream-PBX Header is off, Use P-Access-Network-Info Header is off, Use P-Emergency-Info Header is off… if they’re active, calls or register don’t work.
On Settings > General Settings > Use NAT IP: is set to the external WAN IP (it’s static).
Does anyone have a bit of insight here? I’ve been like this for a month, and have no clue.