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“DTMF RTP EVENT” decoding not quite right in Wireshark 2.0.5

0

I ran into an issue with Wireshark 2.0.5 not decoding one direction of DTMF Relay (RFC2833).

In the attached trace, the DTMF events are decoded when coming from 10.0.0.12, but when coming from 192.168.21.55 it just shows...[Payload type: DynamicRTP-Type-96 (96)]

Now, I have a very old version of Wireshark still loaded because of some needed plugins that only run on version 99.6a. I decided to open in that version, and it decodes perfectly.

Has anyone else run into this issue, or does it seem to be an isolated case due to something I am doing?

Thanks for any help/input anyone can provide.

Travis

PCAP DOWNLOAD LINK --=> DTMF_RTP-EVENT.pcap

asked 24 Aug '16, 20:47

Rooster_50's gravatar image

Rooster_50
238●9●12●18
accept rate: 15%

edited 24 Aug '16, 20:48

One Answer:

0

Please, file a bug and place its number to a comment here.

Grounds: the SDP in the 200 OK is decoded properly, the
a=rtpmap:96 telephone-event/8000
is there and at proper place, so the VoIP call tracker should have no issues to identify the RTP packets with payload type number 96 as telephone-event (RFC2833) ones also in the calling -> called direction.

As a quick workaround, you may open the preferences of RTP Event protocol (through Edit->Preferences...->Protocols->RTP Event or by right-clicking the RFC 2833 RTP Event line in the packet dissection pane of the packet which was auto-detected and choosing Protocol preferences from the context menu) and change the value of the Payload Type for RFC2833 RTP Events parameter from the default 101 to your 96.

But don't forget to file the bug.

answered 25 Aug '16, 04:04

sindy's gravatar image

sindy
6.0k●4●8●51
accept rate: 24%

Will do, thanks Sindy

(25 Aug '16, 07:45) Rooster_50