Video conferencing uses the same protocols as standard telephony, but there is a difference: while in telephony we have one stream of data in each direction, we have a stream of data and a stream of video in video conferencing. When you capture data on the end device, you will see four streams of data: two streams that you send to the other side and two streams of data that are sent back to you.

Another difference is that some video conference applications are still using the H.323 protocol suite, so instead of troubleshooting SIP problems, you will have to troubleshoot H.225 and H.245 connectivity issues. Due to the fact that most applications use SIP and the IETF protocol stack, we will focus on them only.

How to do it...

What you will get for every conference will be as in the following screenshot:

1. As you can see in the screenshot, there are two streams of data in each direction.
2. On one of them (the first one), we see massive degradation in performance.
3. To focus on it, click on the stream, and then click on Analyze.
4. The following window will open:
   
5. In the preceding screenshot, you see that there are many errors, the bandwidth is unstable, and there are many error statuses:
   • Incorrect timestamp (1) and wrong sequence number (2) are caused by a communication line with high Jitter
   • Payload change (3) occurs when the system on the sender's side changes the codec to a better one to fit into the channel
6. There was a problem here simply because this was a video conference call over an unstable cellular connection.