I can hear the other line, but they do not hear me.

Discussion in '3CX Phone System - General' started by Anonymous, Sep 22, 2006.

  1. Anonymous

    Anonymous Guest


    I have recently setup 3CX Phone System and use the 3CX soft phone, as my client. I have registerd my extensions ok. When I place a call it rings and gets picked up, I can hear the person I called from the other end, but they cannot hear me.

    What am i doing wrong?

    In the General options(Settings) of the 3CX server, the Ports for internal use range from 7000 to 7500, but the port on the 3CX softphone is 5060.

    Could this be the problem perhaps?
  2. 3CXsupport

    3CXsupport New Member
    3CX Staff

    Aug 21, 2006
    Likes Received:

    A VoIP call has two parts:

    One is the call initiation that is done with SIP. This protocol is resposible for call placing, tear down and end point registrations (amongst other things). SIP works on port 5060.

    On the other hand (other part) all vioce data is carried across the network via RTP. RTP is usually on higher ports, in the case of our software the default is for the 3CX PhoneSystem to use UDP7000-7500 (customizable). Since you are trying an internal call (both people are on the same network subnet) you should not have any problems with these ports, but it looks like the other user cannot 'receive' your RTP data. Can you check if the callee (not caller) user has a personal firewall that may be blocking you? perhaps you can see it's logs.

    Or were you talking about an external call? i.e. a call made through a VoIP gateway or VoIP provider.

    Thanks for your time and feedback.
  3. jjdelrisco

    Sep 15, 2006
    Likes Received:

    Hello, this has happed when I erase and create the data again in the SIP Account Settings of X-Lite I Also when it changes the address IP of my VoIP Gateway with interface FXS to connect a similar telephone. and the form that works is with giving reload to the PC where this running the SW 3CX.

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