When this process finishes successfully, turn the nodes on with omf tell -a on -t 22,23,18,19 (Note that the command above is all one line, and there are no spaces between the commas and resource names.) From the WITest console, run: omf-5.4 load -i wifi-experiment.ndz -t 22,23,18,19 (Alternatively, you can use the "outdoor" or "sb4" testbeds at ORBIT, with some modifications to the instructions.) Prepare the testbedįirst, load the wifi-experiment.ndz disk image onto four testbed nodes: node22, node23, node18, and node19. For more information, see the WITest reservation tutorial.Īt your reserved time, SSH into the WITest console ( ) using your GENI Wireless username and keys associated with that account. Click on "Testbed" and "Make a reservation", then click on the grid squares corresponding to the date/time you want. To reserve time on this testbed, log in to by clicking on the user icon in the top right corner and then choosing "Log in with GENI". In this experiment, I used the WITest wireless testbed. We also observe the acknowledgment of this frame:Īs well as the second transmission of the frame (from AP to destination STA) and its acknowledgment. In this experiment, we identify the 802.11 frame fields from the raw hex dump of a captured packet:
LLC protocol data unit or MAC control information. Frame Body: Contains an MSDU or a fragment of an MSDU.Mentation and reassembly, and a 12-bit sequence number used to numberįrames sent between a given transmitter and receiver. Sequence Control: Contains a 4-bit fragment number subfield, used for frag.Ter address and the destination address may be identical to the receiver The source address may be identical to the transmit. Finally the source address and destination address are the MACĪddresses of stations, wireless or otherwise, that are the ultimate source andĭestination of this frame. Mitted specifically, the SSID is the MAC-level address of the AP for this BSS Larger configuration the SSID identifies the BSS over which the frame is trans. For an IBSS, the SSID is a random number gen-Įrated at the time the network is formed. The service set ID (SSID) identifies the wireless LAN over
The transmitter address and receiver address are the MAC addresses of stations joined to the BSS that are transmitting and receiving frames over Addresses: The number and meaning of the 48-bit address fields depend on context.In some control frames, this field contains an association, or connection, identifier. Duration/Connection ID: If used as a duration field, indicates the time (in microseconds) the channel will be allocated for successful transmission of a MAC frame.Control information includes whether the frame is to or from a DS, fragmentation information, and privacy information. Frame Control: Indicates the type of frame (control, management, or data) and provides control information.The following excerpt from William Stallings "Data and Computer Communications" explains these fields: Image from William Stallings "Data and Computer Communications". (Alternatively, you can use the "outdoor" or "sb4" testbeds at ORBIT, with some modifications to the instructions.)įigure 1 shows the 802.11 MAC frame format:įigure 1: IEEE 802.11 MAC frame format. Finally, you must have reserved time on the WITest testbed, and you must run this experiment during your reserved time. The project lead of the project you belong to must have enabled wireless for the project. You should have already uploaded your SSH keys to the portal. To reproduce this experiment on GENI, you will need an account on the GENI Portal, and you will need to have joined a project. This experiment uses wireless resources, and you can only use wireless resources on GENI during a reservation. It should take about 60-120 minutes to run this experiment, but you will need to have reserved that time in advance. You should do this before your reservation on the wireless testbed.
#Determine ip and mac frame header information for a data packet install
You will have to download and install Wireshark to run this experiment. In this experiment, we will capture traffic on an 802.11 network and observe the 802.11 MAC frame fields using Wireshark. Menu Understanding the 802.11 Wireless LAN MAC frame format Fraida FundĢ0 March 2017 on education, wireless, layer 2, 802.11
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