RTP Stream analysis bandwidth calculation

asked 2018-09-27 18:12:49 +0000

swinster gravatar image

Hi All,

I am struggling to understand the Bandwidth figures shown in the RTP stream analysis window. Googling old posts and the wiki, this seems to indicate that this figure is simply in kbps, which I would expect (or even bps). However, this doesn't seem to tally with the I/O Stats graph. Indeed, this figure seems to make no sense whatsoever.

Here is a screenshot of a TCP RTP stream. You can see that between packet 24782 and 27215 there is a gap of around 6 seconds. However, looking at the bandwidth figure for packet 27215 and beyond in the RTP stream analysis windows shows a result of 17966.01. I'm not sure how this could be as nothing has happened for the last 6 seconds.

TCP RTP Stream

For the most part, the RTP stream analysis window shows a bandwidth figure of around 18,000-19,000.

Looking at the I/O Stats graph for this RTP stream, we can clearly see the break in RTP packets (albeit that the graph shows Time/Date in my local current timezone, and I set Wireshark to show packets with a UTC timestamp), but also that the bandwidth has several spikes (which we never see in the RTP analysis window) and that when things do settle, it is at around 660 kbps. This seems like a much more accurate figure.


No matter how I then look at the bandwidth figure in the RTP analysis, it simply makes no sense to me.

It would be good to get some clarification on this.

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Hmm, sorry the images do not appear to be linked correctly and I cannot upload as my old account was deleted for some reason so I have had to start over. Try:

TCP Stream Analysis


swinster gravatar imageswinster ( 2018-09-27 18:17:39 +0000 )edit