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Network Troubleshooting

When setting up Voicent software you may run into the error:

Failed to Get Response from SIP service

Here’s Why:

When the Voicent Gateway starts, it will first send user registration information to your VOIP service provider. Once the message is received, your VOIP service will send back an acknowledgement message. If you have entered your VOIP information correctly into the Voicent Gateway, then this problem is most likely caused by something blocking the returning message from reaching the Gateway. There are two common causes for this sort of issue:

  • The message is blocked by your firewall program
  • The message is routed to a wrong network address

Check Your Firewall Program

A firewall program is used to enhance internet security by blocking potentially dangerous incoming connections. However, this may also mean legitimate incoming connections are also being blocked. To see if this is the case, you need to check:

  1. Firewall Program on your Computer
    1. To test if this is the problem, try to disable or even uninstall the firewall program (you can always re-install it later). Popular firewall programs include Windows Firewall, McAfee, Norton, AVG, etc.
    2. Once disabled, restart the gateway to see if it can connect. If it works now, you'll need to add firewall exception rules for Voicent software as shown later.
  2. Firewall Program on your Router
    1. Connect your computer directly to the DSL/Cable modem without the router.
    2. Make sure your computer can still get on the Internet. Restart your computer if it does not.
    3. Restart the Gateway to see if it works. If it works now, you'll need to add firewall exception rules to your router.
    4. If you cannot reconnect your computer, try to take a look at your router's log files. Take a look and see if any incoming connections or messages have been blocked.

Configure Network Firewall

Each firewall program is different so please check its user guide for more information.

To adjust your firewall, grant full access to Voicent gateway programs:

  1. Grant Access to Voicent Software

    Your firewall may be blocking Voicent software. In order to grant access, go to the Program Permissions section of your Firewall software. You can find the software under:

    C:\Program Files\Voicent\Gateway\bin or
    C:\Program Files (x86)\Voicent\Gateway\bin

    The following programs must have full access:

    • vgate.exe (gateway user interface and service)
    • vxengine.exe (telephony engine)
    • spengine.exe (speech engine)
    • adclient.exe (local agent)
  2. Open Ports that are used by Voicent Software

    The following is a short summary of the ports necessary to forward for our software to work correctly. Read this comprehensive Port Forwarding Guide for more information.

    • The standard gateway ports: 8155, 8165 (TCP)
    • Standard SIP port: 5060 (TCP/UDP) + LineNumber
    • SIP audio port: 9156 (UDP) + 2 x LineNumber

    When Using Remote Agents:

    • Gateway Remote Agent Port: 8455 + LineNumber TCP
    • Gateway Remote Agent Audio Port: 8455 + LineNumber UDP

    Where LineNumber is (0, 1, 2, 3, … , max licensed lines – 1). For example, the 2nd line uses 5061 and 9158.

  3. Check Your Network Connections

    When your computer has multiple network adapters, the returning message may not be able to find the correct connection address.

    1. Disable Wireless Connection
      • Most laptop computers have at least two network connections. One wireless and the other wired connections. For Voicent software, it is best to use a wired network connections. Not only will it have much better bandwidth, but it will also be more reliable.
      • Go to Windows control panel to disable wireless networks, make sure you can still connect to the Internet. Restart the gateway.
    2. Do not use Virtual Network
      • Virtual network connections, such as those used by VMware, may not work well. It is strongly recommended to use a dedicated computer for Voicent software, especially when you try to make a lot of simultaneous calls.

Some More Troubleshooting Tips

  1. Make sure the "domain name" entered in your SIP account on Voicent Gateway is correct:
    • For example, for Callcentric, it is "", and for SkypeConnect, it is "". If you use the Phone Setup Wizard, this should be setup for you automatically.
  2. Make sure your computer can reach the domain:
    • Open the Windows Command Window (Windows Start > Run > type in " cmd.exe ")
    • Enter the following in the command window: ping <domain_name> where <domain_name> is the domain name you entered. For example, use "ping " if you are using the Skype Connect service.
    • You should see replies from the service. If you see "ping cannot find host", that means your computer cannot even contact the domain. Ask your network admin to look into this problem.
  3. Configure Your STUN server settings:
    • If there is a firewall between your computer and your SIP service provider, you need to specify the STUN server on the SIP configuration page of the gateway. Some SIP providers offer their own STUN server, others don’t. You could use free STUN servers like
    • Please note that the number after colon of a STUN server is the port number. For example, if your SIP service provider gives you for your STUN server, you need to set the STUN server as and set the STUN port as 10000. In most cases, you should use the default port number.
  4. Make sure your computer is not too slow:
    • If you have a computer with an Intel i3 CPU and at least 3 GB of memory, the computer should be fine. If you have an older computer, check to see if you need to add more memory. For example, to run Windows 7, you need at least 2 GB of RAM. If you only have 2 GB, then running Voicent software difficult.
  5. Try Voicent software in a different location, just to make sure it is not a network connection issue.
  6. Try a different VOIP service

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