Wireshark-dev: [Wireshark-dev] rrc-lte over udp
From: Karunkaran Kumar <[email protected]>
Date: Sun, 3 Jan 2016 01:51:38 +0530
Hi all,

I recently learned about the LTE support on wireshark -- mac-lte, rlc-lte, pdcp-lte and rrc-lte.
The heuristic dissection (i.e., using UDP framing) of the lower layers (i.e., mac,rlc,pdcp) fits my needs exactly.
However, the rrc-lte apparently does not have have such an analogous UDP framing format and heuristic dissection. (Kindly correct me if I am wrong).

I am actually in need of such a functionality. I however do not want to add pseudo mac/rlc headers and use the existing UDP framing. So is it a good idea to try and write a heuristic dissector for this?

As far as my understanding goes, I would require one TAG field perpended to the RRC packet, which would identify the type of the RRC packet -- i.e., BCCH.BCH, BCCH.DL.SCH, DL.CCCH, PCCH, etc...
The reason I think so, is because the 3GPP message decoder (http://3gppdecoder.free.fr/?q=node/1) given in the RRC-LTE web page (https://wiki.wireshark.org/LTE%20RRC) takes a byte stream and a combo-box with these options (BCCH.BCH, BCCH.DL.SCH, DL.CCCH, PCCH, etc...) alone for decoding the packet.

Could anyone kindly advise me on this. Is this correct and whether or not it is a good idea to do this... I saw that few others have also wanted such a similar heuristic decoder for rrc, however they were suggested workarounds as mentioned above (using pseudo mac/rlc layer).

Looking forward to a reply,
with regards,
k kumar

PS: I am a HUGE fan of Wireshark. :)