WLAN Network Services

Find out about the WLAN network Services - a survey of 802.11 wireless network services. There are nine WLAN network services. Three of them are for data transfer, remaining six are for management operations. With services network can track stations and deliver frames accordingly.

They are divided into two main groups:

Station services - every product that uses WLAN must incorporate Station services. They are provided by stations and access points.

Distribution system services connect access points to the distribution system. Access point job is to connect wireless and wired part of the network. This is done by Distribution system services.

Let’s see description of all nine WLAN network services:

1) Distribution - mobile stations are using it, when they send data.
Access point uses the distribution service to deliver frame to the destination. Any communication towards access point and between stations in same BSS, uses distribution service.

2) Integration - service that provide distribution system.
It enables connection to wired networks.

3) Association - registration of mobile stations to access point.
You can’t have any traffic with your station, if you aren’t associated to access point. With association you are “plugged” in network.

4) Reassociation - switching station to another access point.
When a station moves within one extended service area, it needs to track signal strength. When the signal strength, from the associated access point, is too weak, station reassociates to other access point with better signal strength. When reassociation is finished, distribution system updates its location records.

5) Disassociation - termination of association.
With disassociation, the station is disconnected from the network. Data about disassociated station has to be removed.

6) Authentication. Wireless network doesn’t have the same level of physical security as wired networks. Wireless networks must use additional authentication routines to be sure that stations using this network are authorized to do so.

7) Deauthentication - terminates authentication. Deauthentication is termination of association.

8) Privacy - WLAN networks use an optional privacy service called Wired Equivalent Privacy (WEP). If you want to have physical access to a network, you need to pass WEP. Unfortunately WEP doesn’t justify its name. It is very easy to crack WEP. It doesn't take more than 2 minutes. WEP2 was also introduced, but attackers only need to spend more time for breaking it.

Don’t be afraid, I will show you much better options (802.1x and WPA) for security that are incomparable to WEP on what is WPA.

9) MSDU delivery - MAC Service Data Unit delivery service is responsible for delivery data to the destination.

With WLAN network services you have better view of wireless processes.

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