Cace Technologies AirPcap Wireless Capture Adapters Brief Introduction to, Terminology, Standards

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A Brief Introduction to 802.11

Terminology

The terms Wireless LAN or WLAN are used to indicate a wireless local area network, e.g. a network between two or more “stations” that uses radio frequencies instead of wires for the communication.

All components that can “connect” to a WLAN are referred to as stations.

Stations fall into one of two categories: access points or wireless clients.

Access points transmit and receive information to/from stations using radio frequencies. As we shall see later, the particular choice of a radio frequency determines a wireless “channel.” An access point usually acts as a “gateway” between a wired network and a wireless network.

Wireless clients can be mobile devices such as laptops, personal digital assistants (PDAs), IP phones or fixed devices such as desktops and workstations that are equipped with a wireless network interface card.

In some configurations, wireless devices can communicate directly with each other, without the intermediation of an access point. This kind of network configuration is called peer-to-peeror ad-hoc.

A Basic Service Set (BSS) is the basic building block of a WLAN. The “coverage” of one access point is called a BSS. The access point acts as the master to control the stations within that BSS. A BSS can be thought of as the wireless version of an IP subnet. Every BSS has an id called the BSSID, which is the MAC address of the access point servicing the BSS, and a text identifier called the SSID.

802.11 Standards

802.11is a standard that defines the physical layer and the data-link layer for communication among wireless devices. The original 802.11 specification was ratified in 1997, uses the 2.4 GHz frequency band, and allows transmission rates of 1 or 2 Mbps.

802.11a, ratified in 1999, is an extension of 802.11 that operates at 5 GHz. It supports 8 additional transmission rates: 6, 9, 12, 18, 24, 36, 48 and 54 Mbps.

802.11b, ratified in 1999, is an extension of 802.11 that uses the same 2.4 GHz frequency band, and supports two additional transmission rates: 5.5 and 11 Mbps.

802.11g, ratified in 2003, is backward compatible with 802.11b, and supports the same additional transmission rates found in 802.11a: 6, 9, 12,

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AirPcap User’s Guide

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Contents Family of Wireless Capture Adapters User’s Guide Copyrights Contents and Figures Figures AirPcap Product Family AirPcap AirPcap Tx AirPcap Ex AirPcap NBrief Introduction to TerminologyStandards Channels Types of Frames How AirPcap Adapters Operate Http//standards.ieee.org/getieee802/802.11.htmlMultiple Channel Capture applies to USB adapters only Configuring the Adapters the AirPcap Control Panel Identifying the AirPcap AdaptersSettings AirPcap N and Extension ChannelSettingWEP Keys List improves performance Multi-Channel Aggregator AirPcap and Wireshark Identifying the AirPcap Adapters in WiresharkWireless Toolbar Wireless toolbar has the following controls Wireless Settings Dialog Parameters that can be configured are Decryption Keys Management Dialog in Wireshark Decryption Keys Management DialogAirPcap User’s Guide Transmit Raw 802.11 Frames on Your Network Where to Learn More 5GHz Band Appendix a 802.11 Frequencies4GHz Band Channels Supported by the AirPcap Product FamilyAirPcap N

AirPcap Wireless Capture Adapters specifications

Cace Technologies AirPcap Wireless Capture Adapters are essential tools for network professionals aiming to monitor, analyze, and troubleshoot wireless networks. These innovative devices enable packet capture and analysis over 802.11 wireless networks, providing insights that are crucial for maintaining network integrity and performance.

One of the main features of AirPcap adapters is their ability to capture raw 802.11 packets in real time, including management, control, and data frames. This capability allows for a comprehensive view of wireless communications, assisting engineers in identifying issues like signal interference, unauthorized access points, and potential security breaches.

Another significant characteristic is the support for both 802.11a/b/g/n standards. This wide-ranging compatibility ensures that users can effectively analyze traffic across various network types, regardless of the generation of equipment being utilized. Additionally, AirPcap adapters are equipped with advanced features like packet injection, which is beneficial for testing network robustness and security defenses.

The wireless capture adapters are often praised for their seamless integration with popular analysis tools such as Wireshark. This combination provides users with a powerful interface for performing in-depth packet analysis, enabling the decoding of complex protocols and offering visualizations that aid in understanding network behaviors.

For ease of use, AirPcap adapters come equipped with a compact design and user-friendly software. They can be connected to laptops or portable devices, making them ideal for field use. Their portability ensures that field technicians or network analysts can perform assessments in various environments without the need for extensive setup or configurations.

Security is another critical aspect where AirPcap shines. These adapters allow for the capture of encrypted packets, provided the user has the appropriate decryption keys. This feature is particularly valuable for troubleshooting security protocols and ensuring that data transmitted over the network is secure.

In conclusion, Cace Technologies AirPcap Wireless Capture Adapters are versatile and powerful tools for any network engineer or security professional. With their ability to capture and analyze a wide range of wireless traffic, their compatibility with industry-standard tools, and their advanced features, AirPcap adapters are indispensable in today's increasingly wireless world. Whether used for routine monitoring, troubleshooting, or security assessments, these adapters offer a robust solution for wireless network management.
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