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Viewer or Load Capture File to start the software and used only for viewing capture files).
To manually unframe your data:
1. Select Unframe from the File menu on the Control window. Unframe is only available if a protocol
stack was used to capture the data and there is currently no protocol stack selected.
In addition to choosing to Unframe, you can also be prompted to Unframe by the Protocol Stack Wizard.
1. Load your capture file by choosing Open from the File menu on the Control window.
2. Select the file to load.
3. Choose Protocol Stack from the Options menu on the Control window
4. Select None from the list
5. Click Finish. The Protocol Stack Wizard asks you if you want to unframe your data and put it into a new
file.
6. Choose Yes.
The system removes the frame markers from your data, puts the unframed data into a new file, and opens the
new file. The original capture file is not altered.
See Reframing on page 39 for instructions on framing unframed data.
4.2.5 How the Analyzer Auto-traverses the Protocol Stack
In the course of doing service discovery, devices ask for and receive a Protocol Descriptor List defining which
protocol stacks the device supports. It also includes information on which PSM to use in L2CAP, or the channel
number for RFCOMM, or the port number for TCP or UDP. The description below talks about how the analyzer
auto-traverses from L2CAP using a dynamically assigned PSM, but the principle is the same for RFCOMM channel
numbers and TCP/UDP port numbers.
The analyzer looks for SDP Service Attribute Responses or Service Search Attribute Responses carrying protocol
descriptor lists. If the analyzer sees L2CAP listed with a PSM, it stores the PSM and the UUID for the next protocol
in the list.
After the SDP session is over, the analyzer looks at the PSM in the L2CAP Connect frames that follow. If the PSM
matches one the analyzer has stored, the analyzer stores the source channel ID and destination channel ID, and
associates those channel IDs with the PSM and UUID for the next protocol. Thereafter, when the analyzer sees
L2CAP frames using those channel IDs, it can look them up in its table and know what the next protocol is.
In order for the analyzer to be able to auto-traverse using a dynamically assigned PSM, it has to have seen the SDP
session giving the Protocol Descriptor Lists, and the subsequent L2CAP connection using the PSM and identifying
the source and channel IDs. If the analyzer misses any of this process, it is not able to auto-traverse. It stops
decoding at the L2CAP layer.
For L2CAP frames carrying a known PSM (0x0001 for SDP, for example, or 0x0003 for RFCOMM), the analyzer
looks for Connect frames and stores the PSM along with the associated source and destination channel IDs. In this
case the analyzer does not need to see the SDP process, but does need to see the L2CAP connection process,
giving the source and destination channel IDs.
TELEDYNE LECROY Chapter 4 Capturing and Analyzing Data
40 Frontline BPA low energy Hardware & Software User Manual