Wireshark-users: [Wireshark-users] Filtering AMR rates in RTP

From: Andreas Byström (Polystar T & M) <andreas.bystrom@xxxxxxxxxxxx>
Date: Fri, 19 Dec 2008 11:44:56 +0100

Hi,

 

I’m trying to filter a trace of an AMR rtp stream. The AMR (narrowband, nb) is coded in “bandwidth efficient mode” and I’m guessing that’s why I don’t get my filter to work.

I want to filter on the “frame type index” and found the following filter that I thought would work:

amr.nb.toc.ft == 5  (where 5 is the rate 7,95)

 

However, applying this filter on my trace gives an empty result. If I display the whole trace I see that there are several ARM packets with this frame type index.

 

Anyone have an idea on what filter I should try instead or if I have done something wrong? I’m not sure if I’m allowed (or should) send attachements to this mailing list, but I have a trace that I can post if someone is interested in trying different filters on my capture file. Let me know if I should do this

 

Regards,

// Andreas