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Q.921 decoding mistake

0

I analyze SCTP/Q.921 IUA/Q.931 message and wireshark version 1.4.3 decodes them correctly.

In a newer version (2.2.4) however, the IUA.DLCI.SAPI = 0 value is decoded as Radio Signaling Procedures and the upper layers get corrupted. In the older wireshark version the same parameter value is decoded as Call Control Procedures and the upper layer are shown correctly.

Reference, page 11: https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-Q.921-199709-I!!PDF-E&type=items

Please look at it and correct if possible.

Thank you Mark Ersek

asked 03 Mar '17, 00:23

Mark%20Ersek's gravatar image

Mark Ersek
6113
accept rate: 0%

1

A proper filed bug report, with sample capture, would get you a long way of getting this solved.

(03 Mar '17, 01:38) Jaap ♦

One Answer:

1

In newer Wireshark, go to IUA dissector preferences and uncheck "Use GSM SAPI values" option.

answered 03 Mar '17, 02:47

Pascal%20Quantin's gravatar image

Pascal Quantin
5.5k1060
accept rate: 30%

Thanks, this helps. Mark

(03 Mar '17, 02:59) Mark Ersek