Cisco Wireless LAN Controllers
Cisco makes wireless LAN management easier for IT staff through the Cisco Unified Wireless Network, in which a wireless control module of some type is the central or key component.
This control module can be a standalone component like the Cisco 2100 Series Wireless LAN Controller or could be integrated into another device like the Cisco Catalyst 3750G Integrated Wireless LAN Controller; in either case, the WLC components allow you to centrally manage and configure a number of access points (APs) in a simplified manner.
Without this help, management of wireless local area networks (WLANs) can be challenging today with the widespread deployment of access points (APs). In networks where there is currently no wireless access, IT staff experience pressure to deploy a wireless solution; in established networks, the pressure is usually to increase coverage in the current solution.
If you are going to deploy more than three APs on your network, either to start with or later on, seriously consider deploying a WLC-based solution.
To have Wireless LAN Controller (WLC) services on your network, you can use any of the following:
Cisco Small Business Pro Wireless Express 526 Mobility Controller with 521 Wireless Express Access Point (simplified management)
Cisco 2100 series controller
Cisco 4400 series controller
Cisco 5500 series controller
Catalyst 6500 Series Wireless Services Module (WiSM)
Cisco 7600 Series Router Wireless Services Module (WiSM)
Cisco 28/37/38xx Series Integrated Services Router with Controller Network Module
Catalyst 3750G Integrated Wireless LAN Controller Switch
The Cisco Wireless LAN Controller is used to manage all aspects of multiple APs and can also take care of all your Radio Resource Management (RRM). RRM is the term given to managing your wireless radios, and it includes not only channel selection and signal power, but also deals with managing interference from unknown sources.
The two WLC devices that you will likely encounter most often are the Cisco 2100 series controller or the Cisco 5500 series controller.
The Cisco 2100 series controller: This controller has eight network ports on it; two ports support POE to power APs, and the other ports can be assigned as management interfaces or assigned to support various VLAN and network connections that you may be using to isolate traffic for your SSIDs. This WLC system can manage up to 24 APs.
The Cisco 5500 series controller: Depending on the model of the Cisco 5500 series controller you look at, you can manage up to 500 APs through up to eight network ports (transceiver slots), which are used as distribution system ports. This series of controller is typically connected to a network switch, which would provide network services for your APs.