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Hi ,

Iam developing a custom dissector on top of UDP which uses PDCP layer PDU RFC 2507 Selective Repeat ARQ Mechanism for segmentation and Reassembly.

My message contains

          Beginning of Message

          continuation of message and

          end of message

Messages are not coming in sequence and based on sequence number and message id i need to reassemble.

I dont know whether i should use

          conversation or

          add_fragment_seq_next or

          add_fragment_seq_check

Please suggest. I got stuck with this for long time.

asked 16 Feb '15, 02:17

umar's gravatar image

umar
26222427
accept rate: 0%

You are giving to little information for us to be able to help you. Wireshark has a dissector for 3GPP TS 36.323 PDCP googling there is also 3GPP TS 25.323. The RFC you reference deals only with header compression... If the messages are not comming in sequence there should be a sequence number in them I suppose and of course you need to use that for reassembly.

(16 Feb '15, 07:08) Anders ♦

Hi anders thank you very much for your reply. Actually iam using sequence number for reassembly. my fragment table is always returning NULL value. I have posted my code here and yet to get reply. Can you have a look please. I have gone through many example code in epan library but could not find anything. Don't know why my frag_head is empty. Please help . Thanks

https://ask.wireshark.org/questions/39824/fragmentation-error-status-access-violation

(16 Feb '15, 08:34) umar

For reference, the answer was given in this wireshark-dev mailing list thread

permanent link

answered 17 Feb '15, 03:23

Pascal%20Quantin's gravatar image

Pascal Quantin
5.5k1060
accept rate: 30%

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question asked: 16 Feb '15, 02:17

question was seen: 1,395 times

last updated: 17 Feb '15, 03:23

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