8 viewing protocol messages and transactions, Viewing l2cap messages in protocol messages, How to decode – Teledyne LeCroy BTTracer_Trainer - BTTracer Users Manual User Manual

Page 146: Expanding protocol messages, Viewing protocol messages and transactions

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BTTracer Protocol Analyzer User’s Manual

CATC

SW Version 2.20

9.8 Viewing Protocol Messages and Transactions

By pressing a button such as

or

, you can cause BTTracer to

decode

the higher level protocol data contained within L2CAP messages and
display them as packet-like rows called Protocol Messages. Protocol
Messages have headers marked "protocol" and fields that vary in
appearance and content depending on the type of protocol.

Some Protocol Messages can be grouped into a higher level entity called a
Protocol Transaction. A Protocol Transaction is a row in a trace that
summarizes the higher level protocol data that is transmitted between a
Master and Slave device when one sends a request and the other sends back
a response. For example, if you press

,

BTTracer will locate SDP

requests and responses between a Master and Slave device summarize their
data.

Viewing L2CAP Messages in Protocol Messages

If the protocol heading is double-clicked, the L2CAP data-transfer
messages that make up the protocol will display below the protocol. You
can also expand the protocol by left-clicking the small downward pointing
arrow on the protocol header.

How to Decode

Decoding Protocol messages is the same process as decoding LMP and
L2CAP messages.

Using the Toolbar - To decode using the Toolbar, press one of the protocol
decode buttons such as:

.

.

Using the Menu - To decode using the menu, select:
Setup>Display Options

Then select one of the decode checkboxes.

Once a decode command has been issued, BTTracer will create Protocol
Messages in the trace. You will probably have to hide hops, polls, and null
packets and then scroll through the trace in order to find Protocol messages.

Expanding Protocol Messages

Protocol messages can be expanded to reveal their constituent packets using
any of the following methods:

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