5 viewing packets in lmp and l2cap messages, 6 types of lmp and l2cap messages – Teledyne LeCroy BTTracer_Trainer - BTTracer Users Manual User Manual

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134

BTTracer Protocol Analyzer User’s Manual

CATC

SW Version 2.20

9.5 Viewing Packets in LMP and L2CAP Messages

LMP and L2CAP Messages can be "opened" to reveal
their constituent packets by double-clicking the first
cell in of the message or clicking once on the small
arrow on that same cell. The packets will then display below the message.
The following screenshot shows an example of a message and its packets.

9.6 Types of LMP and L2CAP Messages

If you scroll through a trace, you will see three kinds of message:

LMP Signalling Message

L2CAP signalling Message

L2CAP Data Transfer Message

Each message has the same basic message header but differs in its payload.

LMP and L2CAP Signalling messages have payloads of commands for
establishing LMP and L2CAP channels. L2CAP Data-Transfer messages
have a payload that may include RFCOMM, SDP, or TCS data. In order to

Message

Packets
making up
the
message

LMP Signalling Message

L2CAP Signalling Message

L2CAP Data Transfer Message

Payload

Payload

Header

Payload

Header

Header

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