When you define either an Advanced or Lite Data Message Flow, you can provision the DMF messages from a existing message trace rather than manually defining the messages.
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PCAP to DMF Wizard |
The PCAP to Lite DMF Wizard imports the application-layer packet data from a trace saved in a Packet Capture (PCap) format into DMF messages maintaining the order in which they are sent/received. Additionally, the PCAP to Lite DMF Wizard also allows you to import the timing between packets.
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The following topics lists the steps involved in importing a PCAP file. If you are not familiar with defining DMFs and messages, review the information in Learn the basics before you begin.
| NOTE: The PCAP importer matches the limitations of the Lite DMF such as : Import 128 up to Streams. Each Stream can only have up to 10MB of data. Each Message can only have 65KB of data. |
Before you import a message trace, you should have a basic understanding of:
You can use Wireshark to filter out the packets that should not appear in the final message flow, if necessary, and to export the trace in a PCAP format.
Filtering a message trace — If your trace contains packets from devices other than the client and server or packets with protocols unrelated (non UDP/IP and TCP/IP) to the final message flow, use Wireshark's packet filter to weed out the undesirable packets. Ideally the PCAP file only contains the packets that are expected to be imported. Remove any non UDP/IP and TCP/IP packets as they will be skipped by the PCAP Wizard and a warning displayed.
Most likely the source of the pcap is from some other real network or device or system.
See Capture Packets to capture packets transmitted through specific ports during the test.
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1. |
Edit the test case that will execute your DMF and configure it for Continuous Data Traffic (see Adding Data Traffic). |
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2. |
Add a New Lite DMF and the Lite Data Message Flow window... opens. |
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3. |
Click the Import PCAP button to start the PCAP to DMF Wizard. |
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4. |
Click ... and navigate to the file that you exported in the Prepare PCAP File section, choose the file, and click Select. By default, files with ".pcap/.cap" extensions are displayed. Select All Files from the Files of Type drop-down if necessary, and all files in that location are displayed. Only files with a PCAP format can be imported with the wizard. Ensure that the file path and name are displayed next to the ... button. |
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Select Import packet Timings into Message Send Delays to automatically set the message Send Delay based on the packet timings in the PCAP (provides a capture replay type functionality). The timings will be relative to the first message included in the DMF, that is, message 0 will have a time of 0. Set the Number of bytes to preview per message. Default is 64Bytes. This allows you to limit the amount memory used during import. |
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Click Next to continue to the next step. |
Select Streams/Connections/5-Tuples (page 2)
The second page of the PCAP to DMF Wizard displays imported data Streams and Packets in two different panes.
| NOTE: You may use the left and right arrow in between the two panes to hide/view the panes. |
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Select Stream |
Select the required stream and the corresponding packets are selected in the View Packets pane on the right.
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Click Next |
To Continue to the next step, which opens the Reassemble Packets into Messages window.
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Reassemble Packets into Messages (page 3):
The Reassemble Packets into Messages window allows you to combine multiple packets into one message stream for the DMF. That is, you may combine the fragmented TCP stream based and IP Packet based data into one message for the DMF. You may select a stream, multiple packets of the stream and reassemble them.
| NOTE: You may use the left and right arrow in between the two panes to hide/view the panes. |
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Select a Stream |
Indicates that you are required to a select a before you are allowed to perform any further action. When no stream is selected, all packets from all streams display. Select Flip Source/Dest direction if the PCAP is from or to be viewed from a different perspective. |
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Select Packets |
Available only when you have selected a stream. Select more than one packet transmitted in the same direction.
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Reassemble Packets |
Available only when you have selected multiple consecutive packets that are all sent in the same direction. Select the packets that need to be reassembled and click Reassemble Packets. Multiple selected packets are reassembled into one message (of with length = the size of all the packets together).
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Finish |
Click Finish to open the imported PCAP file with assembled packets in the Lite Data Message Flow window.
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