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Bug #5241

open

GTP: Malformed Packet pdp ctx response.

Added by keith 2 months ago. Updated 2 months ago.

Status:
New
Priority:
Low
Assignee:
-
Category:
libgtp
Target version:
-
Start date:
09/29/2021
Due date:
% Done:

0%

Spec Reference:

Description

I have some Alcatel 1066G feature phones.

I notice they do have a "browser" and they are Class 12 devices.

I don't see any IP traffic from them though, when using the browser.

Wireshark notes a "Malformed Packet" in the create pdp ctx response, however this only happens with GTP version 1.

(Wireshark can't parse the QoS IE, even though it is the same IE as the one in the pdp ctx request)

  • These phones do have some strange behaviour - for example:
  • When choosing the "Network Account" (APN) to use for the browser, it doesn't always respect what you set, even after power cycle.
  • It doesn't always delete the PDP context on shutdown.
  • The APN profiles have an option for IP v4/v6/both, but it doesn't respect it and always asks for IPv4v6

Maybe some of the above behaviour may be due to error from the network?
I don't care about getting data working on this device, but maybe it's pointing out a bug in libgtp to us?

THe main difference I can see in the pdp ctx requests/response with this and other phones is the length, with this alcatel QoS IE length is 11, with others it is 14.


Files

pdp_ctx_malformed.pcap pdp_ctx_malformed.pcap 438 Bytes keith, 09/29/2021 07:47 PM
Actions #1

Updated by keith 2 months ago

  • Description updated (diff)
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