VOIP and SIP issues

VOIP and SIP issues

If test voice notifications via VOIP are experiencing difficulties, we recommend the following tests and procedures:
  • TopView version: Make sure you're running the most recent version of TopView possible, along with any patches for that version.

  • Credentials: Verify that the authorization name and password are correct for the SIP server

  • Try other softphones: Can a softphone installed on the same computer as TopView connect to the SIP server? Can it also make and receive calls from the VOIP system?
    Softphones to try:
  • Firewall: Is it possible the firewall is blocking SIP calls? Test your computer's firewall and port settings with the 3CX Firewall Checker client application (instructions below)
    • Audio issues are typically due to the network or a firewall blocking or filtering the communication. SIP communication (call setup) and media (audio) communication happen on different ports, so both the SIP port (5060, or as specified in your SIP server address TopView setting) and the media ports (10000-20000 are the defaults, or as specified in TopView settings) need to be allowed through all firewalls and networks.
    • Run the "RemoteConnectionTest" and verify that the registration test passes.

  • Transport: The default transport for the SIP connection is UDP. Based on your firewall setting or SIP server settings, TCP may work if UDP is failing.

    You can test a TCP connection to the SIP Server using TopView's TCP Connection Test
    Configurator top menu > Tools > Support apps > TCP Connection Test
    Enter your SIP server and port (default 5060). If this test works, you should be able to use TCP as the transport.

  • Audio: If calls can be made but audio is heard, you may need to configure NAT settings for TopView:
    • When you place a SIP call, the call setup data includes your local IP address. When the receiving device tries to send audio (RTP) back to that local IP, the media connection can fail
    • TopView v7.7 enables the configuration of STUN/TURN settings or a static public IP address for traffic.

  • Keypress acknowledgement does not work: If DTMF tones are not detected, see our DTMF issues page for more information.

Running the 3CX Firewall Checker application

You can download the application from our download site: 3CX Firewall Checker client application.

In this example, we ran the checker against a Grandstream VOIP device located in our office.

3cx Firewall Checker
  • 3CX Server IP Address: port
    Enter the IP address or hostname of the SIP Server. If you are not using the default SIP port (5060) enter:port after the SIP Server
  • Extension
    Enter the phone extension that you plan to use in TopView.
    In the TopView Voice Notification setting, this field is named “User name”
  • Authentication ID
    Enter the registration name.
    In the TopView Voice Notification settings, this field is named “Authorization name”
  • Password
    Enter the password for the registration name/Authentication ID.
  • Echo text extension
    Enter the number that you wish to call through the SIP Server. In our example, the Grandstream is configured to make external calls through the analog phone line if the number starts with a 5.
  • Callback test extension
    Do not enter anything here
  • Click [Start test]
    Perform a test call and report any discovered problems. If the test works you should receive a call at the entered “Echo test extension”. If you receive a call you can ignore the Echo Call: Failed! result since the number you called does not perform an echo.

Wireshark to analyze VOIP traffic and SIP calls

Wireshark is a useful tool allowing tracking and analyze of SIP communication. It can even record RTP traffic to listen to the audio coming through the phone call.
See VoIP_calls - Wireshark Wiki for more information.

Other resources

We have a few general posts on TopView's use of VOIP for voice notifications: