Ethereal-dev: Re: [Ethereal-dev] FW: [Ethereal-users] Ethereal hangs when doing RTPStream Anal

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date Index Thread Index Other Months All Mailing Lists
Date Prev Date Next Thread Prev Thread Next
From: "Martin Regner" <martin.regner@xxxxxxxxx>
Date: Wed, 1 Dec 2004 19:53:28 +0100
Francisco Alcoba wrote:
>
> This seems to come from two RTP packets that have inverted timestamps, with the second having the marker bit set;
i.e., the second packet has a timestamp that is lower than the second. In this
> case it also happens that the second packet's sequence number is higher than the first, which is
> strange, but I think this might happen also with plain packet reordering.

RTP packet 2 and 3 have a different payload type (payload type 96, Dynamic Payload type) than packet 1 and 4 (payload
type 8, G.711 A-law).

I think that packet 2 and 3 are rtp-event packets (RFC 2833). Those will have the timestamp corresponding to when the
tone (e.g. DTMF) was started and
the payload will contain the duration from when tone was started, if I remember correct.

There might be several rtp-event packets with same timestamp that are interleaved with normal
voice packets that have stepping timestamps, I think. At least I have seen that in some captures before.

In order to decode payload type 96 as rtp-event it is possible to change Edit/Preferences.../Protocols/RTP Event/Payload
type for RFC 2833 RTP Events.