Wireshark-users: [Wireshark-users] Delta measurements for VOIP calls
From: Adam Harding <adam.harding2@xxxxxxxxxxxx>
Date: Tue, 20 Mar 2007 18:56:25 +0000
Hi,

I have taken some wireshark results of VOIP calls between two computers.

The strange thing I notice is that the delta value seems to alternate between around 30ms and then every 2 or 3 packets goes to near 0ms. I am using the GSM 06.10 codec so I guess they are sending packets out every 30ms so I am expecting the delta value to fluctuate around the 30ms mark so was wondering what was causing it to go down to near 0ms every other packet or so?

This is giving strange results when calculating the mean delta manually in excel. Maybe I should neglect those very small values when calculating the mean delta?

Please see a section of my results below so you can see what I mean.

Thanks,



Packet/seq no.,  Delta,  Jitter, Bandwidth

4932	32561	31.73	14.53	29.2
4933	32562	0.37	14.85	29.78
4936	32563	31.73	14.66	29.78
4937	32564	0.37	14.97	30.37
4939	32565	31.73	14.76	29.78
4942	32566	31.98	14.59	29.2
4943	32567	0.37	14.91	29.78
4946	32568	31.73	14.71	29.78
4948	32569	32.11	14.54	29.2
4949	32570	0.25	14.87	29.78
4952	32571	31.74	14.67	29.78
4953	32572	0.25	14.99	30.37
4955	32573	31.73	14.79	29.78
4958	32574	32.1	14.62	29.2
4959	32575	0.37	14.93	29.78
4962	32576	31.61	14.73	29.78
4964	32577	32.11	14.56	29.2
4965	32578	0.37	14.88	29.78
4968	32579	31.61	14.67	29.78
4969	32580	0.37	14.98	30.37
4971	32581	31.61	14.77	29.78
4974	32582	32.23	14.61	29.2
4975	32583	0.37	14.93	29.78
4978	32584	31.61	14.72	29.78
4980	32585	32.1	14.56	29.2
4981	32586	0.25	14.88	29.78


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