Radio Link Control (RLC) for LTE

This protocol sits between the MAC and PDCP layers in the LTE air interface (connecting an LTE UE with an eNodeB).

Protocol dependencies

The MAC-LTE dissector can call the RLC-LTE dissector for srb1 and srb2 (since it is known that these should be AM). For signalling PDUs, the RLC-LTE dissector can call PDCP-LTE for SRB channels, or LTE_RRC for CCCH channels. This is controlled by preferences (see below).

A UDP framing format for RLC-LTE has been defined (described in packet-rlc-lte.h, purely for use with Wireshark)

Example traffic

rlc_call.png

Wireshark

The RLC-LTE dissector is fully functional. There is support for reading RLC-LTE frames from:

There is an LTE RLC stats window, available from the Telephony menu. This can be useful for finding channels where problems are happening, and setting appropriate display filters.

The same statistics are available from tshark, using the option -zrlc-lte,stats

rlc_lte_stats.png

Also available from the Telephony menu is an RLC Time/Sequence graph.

rlc_graph.png

Preference Settings

Example capture file

XXX - Add a simple example capture file to the SampleCaptures page and link from here (see below). Keep this file short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.

Display Filter

A complete list of RLC-LTE display filter fields can be found in the display filter reference

Capture Filter

You cannot directly filter RLC-LTE protocols while capturing.

Discussion

It is recommended that you use current sources or a recent automated build for this and other LTE dissectors.

RLC-LTE (last edited 2015-11-26 14:49:44 by PascalQuantin)