Jim Geier

The IEEE 802.11 standard includes a common Medium Access Control (MAC) Layer, which defines protocols that govern the operation of the wireless LAN. In addition, 802.11 comprises several alternative physical layers that specify the transmission and reception of 802.11 frames. Let’s take a closer look at the 802.11b Physical Layer, which uses direct sequence spread […]

Similar to their popular handheld and laptop-based analyzers, AirMagnet’s newly-released Duo a/b Laptop Analyzer offers functions such as WLAN administration, installation surveying, security assessments, connection troubleshooting, performance management and operational support functions. The big difference, however, is that the Duo a/b includes support for 5GHz 802.11a in addition to 2.4GHz 802.11b networks. The AirMagnet Duo […]

In a previous tutorial, we discussed the steps for deploying a wireless LAN, which includes requirements gathering, design, installation, testing, and planning for operational support. What we’ll do now is focus on the important steps of installing the distribution system and access points. Careful Planning As with any other project, the planning of a WLAN […]

By definition, a router transfers packets between networks. The router chooses the next best link to send packets on in order to reach closer to the destination. Routers use Internet Protocol (IP) packet headers and routing tables, as well as internal protocols to determine the best path for each packet. Most routers connect a LAN […]

The form factor of an internal wireless radio network interface card (NIC) defines a physical and electrical bus interface that enables the radio card to communicate with a computing device. The barrage of form factors — a fancy way of saying the physical size and shape of a device — demands that you be careful […]

802.11’s Wired Equivalent Privacy (WEP) encryption uses symmetric, private keys, which means both the end user’s radio-based network interface card (NIC) and access point must have the same key. This leads directly to significant difficulties involved with distributing new keys to each NIC periodically. As a result, keys remain unchanged on networks for months. With […]

One of the most critical security concerns of IT managers today is the possibility that rogue wireless access points may be present on the corporate network. A rogue access point is one that the company does not authorize for operation. The trouble is that a rogue access points often don’t conform to wireless LAN (WLAN) […]

When wireless LANs first became available in the early 1990s, primary applications were wireless bar code solutions for needs like inventory control and retail price marking. Data transfers for these types of applications don’t demand very high performance. In fact, 1Mbps data rates are generally sufficient to handle the transfer of relatively small bar codes […]

Ekahau’s Positioning Engine 2.0 provides a software-based system that enables location-based applications for wireless LANs. The complete positioning system includes the Ekahau Client, Ekahau Positioning Engine and Ekahau Manager. Each user device that the system tracks, such as a laptop or PDA, must be running the client software. The Ekahau Positioning Engine is Java-based server […]

The 802.11 standard ensures that all stations, both radio-based network interface cards (NICs) and access points, implement access methods for sharing the air medium. When installing wireless LANs (WLAN), most people don’t give much thought to these mechanisms. A solid understanding of 802.11’s medium access methods, however, will enable you to deal more effectively with […]

After deploying a wireless LAN, you need to implement a security assessment, which ensures that the WLAN complies with effective security policies. For most situations, this is necessary whether or not the network implements effective security mechanisms. Don’t put too much trust in the design of a system. It’s best to run tests to be […]

You’ve probably heard the story by now that 802.11 wired equivalent privacy (WEP) is broken and just about anyone can compromise wireless LAN (WLAN) resources. What you’ve heard is absolutely true, especially if you don’t implement techniques that will counter the known weaknesses. With any WLAN, you need to consider policies that will protect resources […]