Using Wireshark to diagnose VOIP problems

Nowadays, VOIP services and software are easier to setup. But from time to time, you may still have issues like not being able to connect to your VOIP service, not getting audio when a call is made, or just getting one way audio. These issues are usually related to your network connection, such as your router, firewall on your router, firewall on your computer, etc, and they are relatively hard to diagnose.

A nice tool to use to diagnose these problems is Wireshark, which is a networking traffic monitoring tool that understands VOIP protocols. It is also free.

It is a technical tool and may only be suitable for tech savvy users.

Here are the steps to use this tool:

1). Start the capture and set “sip” or “rtp” as the filter, hit apply
2). Restart Voicent gateway
3). Make a test call.
4). Check the capture result and stop the capture.

If you have audio related issues, select “rtp” as your filter. If you have two way audio, you should see packets sent and received from the computer. If you only see one way traffic, then the audio for that direction is somehow blocked.

If you have connection issues, select “sip” as your filter.