ACCESS POIINTSAn access point (AP) provides the connection between one ormore wireless client devices and a wired local area network(LAN). The AP is usually connected to the LAN via aCategory-5 cable connection to a hub or switch. Clientdevices communicate with the AP over the wireless link, givingthem access to all other devices through the hub orswitch, including a router on the other side of the hub, whichprovides Internet access (Figure A-1).An AP that adheres to the research 802.11b Standard foroperation over the unlicensed 2.4-GHz band supports a wirelesslink with a data transfer speed of up to 11 Mbps, whilean AP that adheres to the research 802.11a Standard for operationover the unlicensed 5-GHz band supports a wireless linkwith a data transfer speed of up to 54 Mbps. Access pointsinclude a number of the following functions and features: Radio power control for flexibility and ease of networkingsetup Dynamic rate scaling, mobile Internet Protocol (IP) functionality,and advanced transmit/receive technology toenable multiple access points to serve users on the move Built-in bridging and repeating features to connect buildingsmiles apart (The use of specialty antennas increasesrange. The AP can support simultaneous bridging andclient connections.) Wired Equivalent Privacy (WEP), which helps protectdata in transit over the wireless link between the clientdevice and the AP, via 64-, 128-, or 256-bit encryption Access control list (ACL) and virtual private network(VPN) compatibility to help guard the network fromintruders
Directly connected APs
In direct connection, an AP connects to one or two 10/100 ports on a
WSS. The WSS port is then configured specifically for a direct
attachment to an AP. There is no intermediate networking equipment
between the WSS and AP, and only one AP is connected to the WSS
port. The WSS 10/100 port provides power over Ethernet (PoE) to the
AP. The WSS also forwards data only to and from the configured AP
on that port. The port numbers on the WSS which are configured for
directly attached APs reference a particular AP.
Distributed APs
An AP that is not directly connected to a WSS is considered a
distributed AP. There may be intermediate Layer 2 switches or Layer
3 IP routers between the WSS and the AP. The WSS may
communicate to the distributed AP through any network port. (A
network port is any port connecting the switch to other networking
devices, such as switches and routers, and it can also be configured
for 802.1Q VLAN tagging.) The WSS contains a configuration for a
distributed AP based on the AP’s serial number. Similar to ports
configured for directly connected APs, distributed AP configurations
are numbered and can reference a particular AP. These numbered
configurations do not, however, reference any physical port.