MCPTT SDP doesn't decoded

asked 2020-09-09 05:39:16 +0000

Baruchka gravatar image

Hello All,

Does anyone know why Wireshark does'nt decoded part of the SDP xml (media attribute), attached is a screenshot with an error that appear in Wireshark ?

Thanks!

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No screenshot. Post your image on a public share, e.g. Google Drive, DropBox etc. and post a link back here.

grahamb gravatar imagegrahamb ( 2020-09-09 07:55:47 +0000 )edit

Hello,

attached is a link with the screenshot... thanks (https://radcom365-my.sharepoint.com/:...)

Baruchka gravatar imageBaruchka ( 2020-09-09 12:43:39 +0000 )edit

For reference here is the screenshot:

grahamb gravatar imagegrahamb ( 2020-09-09 14:05:58 +0000 )edit

Hi, Without looking at the SDP RFC or Wireshark code I think Wireshark expects a numeral (Dynamic payload) as the first entry in the fmtp. Compare with the audio fmtp:121

Anders gravatar imageAnders ( 2020-09-09 14:42:53 +0000 )edit

Can you provide a capture file?

if (!ws_strtou8(payload_type, NULL, &media_format) || media_format >= SDP_NO_OF_PT) {
                        expert_add_info(pinfo, media_format_item, &ei_sdp_invalid_media_format);
Chuckc gravatar imageChuckc ( 2020-09-09 16:31:05 +0000 )edit

Hi Anders,

attached is apcap file with the Invite message, can you please look and advise

https://radcom365-my.sharepoint.com/:...

Br, Baruch

Baruchka gravatar imageBaruchka ( 2020-09-09 17:10:13 +0000 )edit

That is a packet fragment. Need a frame (or more?) before it to reassemble full packet.

Chuckc gravatar imageChuckc ( 2020-09-09 17:19:38 +0000 )edit

I think it's a wireshark bug, 3gpp ts 24.581 has an fmtp example. An issue should be raised with the packet as an attachment.

Anders gravatar imageAnders ( 2020-09-09 19:57:03 +0000 )edit
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