Building Wireless Community Networks, Second Edition

Wired Wireless

Presumably, no matter how many wireless clients you intend to support, you will eventually need to “hit the wire” in order to access other networks (such as the Internet). There are a number of different kinds of physical devices you can use to jump from wireless back to your wired infrastructure.

Access Point Hardware

APs are widely considered ideal for “campus” coverage. They provide a point of entry to the wired infrastructure that can be configured by a central authority. They typically allow for one or two radios per AP, theoretically supporting hundreds of simultaneous wireless users at a time. They must be configured with an ESSID (Extended Service Set ID, also known as the Network Name or WLAN Service Area ID, depending on who you talk to); it’s a simple string that identifies the wireless network. Many APs use a client program for configuration and a simple password to protect their network settings. All hardware access points provide BSS master services.

Most APs also provide a number of enhanced features. External antennas (or antenna connectors), advanced link status monitoring, and extensive logging and statistics are now common on many APs. In addition, most access points provide two additional security measures: MAC address filtering and closed networks. With MAC filtering enabled, a client radio attempting access must have its MAC address listed on an internal table before it can associate with the AP. In a closed network, the AP doesn’t beacon its ESSID ...