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Wireshark-users: Re: [Wireshark-users] RTP Stream Analyses [Marker Bit]

From: "Anders Broman" <a.broman@xxxxxxxxx>
Date: Fri, 6 Jul 2007 16:57:14 +0200

Hi,

See also http://wiki.wireshark.org/RTP_statistics?highlight=%28rtp%29

Something ought to be done about the Jitter calculation as the Marker bit has different meaning

For Video and Audio.

Regards

Anders

 


Från: wireshark-users-bounces@xxxxxxxxxxxxx [mailto:wireshark-users-bounces@xxxxxxxxxxxxx] För Lars Ruoff
Skickat: den 6 juli 2007 16:40
Till: 'Community support list for Wireshark'
Ämne: Re: [Wireshark-users] RTP Stream Analyses [Marker Bit]

 

From my memories:
packets with the marker bit set don't take part in the jitter calculation.
This is because in RTP audio streams marked packets usually mark the end of silence periods.
The wrong jitter values probably come from the fact that there is no (or at least not the right) sampling clock rate defined for the used payload type.
Both issues would be worth revisiting.

 

Lars

 


From: wireshark-users-bounces@xxxxxxxxxxxxx [mailto:wireshark-users-bounces@xxxxxxxxxxxxx] On Behalf Of Shuaib Siddiqui
Sent: vendredi 6 juillet 2007 16:27
To: wireshark-users@xxxxxxxxxxxxx
Subject: [Wireshark-users] RTP Stream Analyses [Marker Bit]

Hi,

I streaming videos using VLC on the client side and Darwin Streaming Server on server side. When I analyse the rtp stream on the client side using Wireshark, I see some RTP with marker bit set and immediately after such RTP packet the jitter value is very high as compared to the previous one, plus it also displays Incorrect Timestamp. I looked up the marker bit in the RFC 1889 but they just state it as profile specific. Kindly, can anyone provide any further explanation? Plus does the abnormality in the jitter value means the jitter values further on are not credible ?
Thank you for yout time!

Shuaib
--
MSc in Communication Systems
I&C Faculty
EPFL
Switzerland
Home page: http://shuaibe.googlepages.com/