Ucm 6104



I have voice sound problems by extarnal forwarding to my mobile phone , mobile phone is ringing but you can,nt hear any voice this problem is by UCM6102 and by GS Wave on android mobile phone , when i am calling via extension no to other extention it,s rining but you cant hear any voice to speak on both sides like same problem with forwarding to mobile phone via sip phone nr
inbound routes via sip trunk xxxx forward xxxx mobile phn

I have an TP LİNK MODEM TD 9970 i have setup also virtual ports 5060 and 10000-20000

thanks in advance


The TP-LINK router family has a history of issues with SIP. While I do not know that this one does specifically, you have not indicated if SIP ALG has been disabled or how the PBX and extension settings are set. You have also not indicated if using cellular or WiFi or both. If cellular, who is the carrier?

What is set in the External Host field in the SIP settings of the PBX?
Is the SDP field underneath also checked?
Have you defined the local network to the PBX at the bottom of the same page?
In the extension settings of the PBX, have you enabled NAT for the needed extension?
Have you disabled “can direct media”?


This modem is still not able to parse External Ip to internal IP correctly…

TP-Link modems are basic “residential” modems not designed for internal servers, consider replacing it with a more business router for its role…