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Wireshark not dissecting Geographic-location Type 138 and 139

asked 2022-07-27 09:23:35 +0000


This is similar to my quesiton here : I wasnt sure to post a new question or post it there, I decided to post a new question as it is not the same as my original question.

You can see in the screenshot that the type NG-RAN Node ID (138) is not dissected, and also the combined type with 5GSTAI(139). I assume it should be dissected since 5GS TAI type(136) does properly display TAC, MCC and MNC.

From my understanding NG-RAN Node ID should be displayed something like this:

20 -> number of bits in the ng-eNodeB bit string

length value = 18, short ng-eNodeB ID
length value = 20, ng-eNodeB ID
length value = 21, long ng-eNodeB ID
length value = 22-32, gNodeB ID

62 f2 20 -> MCC/MNC (MCC = 262, MNC = 02)

aa aa aa bb -> gNodeB ID

I have uploaded the pcaps to google drive here:

(note that the requests were sent on udp port 2002 so it should be set to decode as RADIUS protocol)

3GPP references:

3GPP TS 29.061 V17.6.0 (2022-03)
3GPP TS 29.274 V17.5.0 (2022-03)

screenshot:alt text

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answered 2022-07-27 14:33:23 +0000

Chuckc gravatar image

updated 2022-07-27 14:34:59 +0000

It's hitting the default: entry since there are no case for 138 or 139. (packet-gtpv2.c).

This would be an extension of work done in 15050: In 3GPP-User-Location-Info AVP Geographic Location Type: 136 is showing unknown / GTPv2: add dissection of newer geographic location types.

Please open a Enhancement Request in the Wireshark Gitlab Issues. (its a bit more than I want to take on and maybe someone else will pick it up sooner)
If you do open an enhancement please add a link back to this question.

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Asked: 2022-07-27 09:23:35 +0000

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Last updated: Jul 27 '22