What is a Wireless LAN controller?
A WLAN controller manages wireless network access points that allow wireless devices to connect to the network. What a wireless access point does for your network is similar to what an amplifier does for your home stereo. It takes the bandwidth coming from a router and stretches it so that many devices can go on the network from farther distances away.
Why is a Wireless LAN controller required in a wireless network?
No more individual MAC address tables and updation in each access point, controller provides for a centralized authentication mechanism through individual user name-password based Radius Server/ Active Directory/ LDAP Integration , centralized MAC address filtering or certificate/ shared key based authentication for all the clients from a central location.
After authentication, all the wireless packets are encrypted end to end using 128 bit encryption technology making it difficult for any casual intruders to get in to your network. Wireless Intrusion Detection/ Prevention Systems (Where dedicated access points can act as scanners for wireless threats) can identify and block a whole range of wireless attacks like: Ad-hoc network Mis-association of AP/Client to other network access points Rogue Access Points detection and prevention Multiple futile attempts to connect to the wireless network Honey pot attacks/ Man-In-The-Middle Attacks Denial of Service Attacks etc. Branch offices and remote offices are also protected as the controller can form a Secure VPN tunnel between the HO and branch locations. Rogue Access Points and Laptop’s can be even located using location visualizers.
QoS: Quality of Service through Traffic Prioritization
A centralized controller based wireless infrastructure can identify and differentiate between different types data packets and prioritize the critical traffic on the wireless network infrastructure – This is crucial for real time wireless traffic like voice, video etc.
Bandwidth Restriction per user/ per group
You can prevent a few wireless users from clogging the entire network by restricting the bandwidth available to them at any point of time. You can also reserve a minimum bandwidth to all the critical users.
Centralized Radio Management for all Access Points
Interference Mitigation Adjacent Access Points are always maintained to operate in different non-overlapping channels by the controller so that there is no loss of packets due to interference in a dense wireless network.
The users are automatically shifted to adjacent access points if the load (number of users connecting) on one access point is high and the neighboring access point is lesser.
A wirless LAN controller enables that clients are connected to the right radios in a multi-radio access point setup.
Clients are automatically shifted to neighboring access points if any access point suddenly fails, thereby introducing redundancy in the network.
Why a Wireless LAN Controller as a Service?
A Wirless LAN Controller setup is quite expensive for the SMB market. While one device can cost more then 1000€, it's not enough for a proper installation. There is a need for 2 devices to have a redundant setup and it should be hosted in a datacenter to be able to cover all locations of an organisation.
On top of that, like all network devices this solution should be montitored 24/7 to guarantee a maximum uptime.
Therefore, the Wirless LAN Controller as a Services is a much more cost effective solution then setup a full infrastructure by an organisation himself.