Proxim AP-4000 User Manual page 114

Advanced Configuration
SSID/VLAN/Security
Figure 4-38 Components of a Typical VLAN
VLAN Workgroups and Traffic Management
Access Points that are not VLAN-capable typically transmit broadcast and multicast traffic to all wireless Network
Interface Cards (NICs). This process wastes wireless bandwidth and degrades throughput performance. In comparison,
a VLAN-capable AP is designed to efficiently manage delivery of broadcast, multicast, and unicast traffic to wireless
clients.
The AP assigns clients to a VLAN based on a Network Name (SSID). The AP can support up to 16 SSIDs per radio, with
a unique VLAN configurable per SSID.
The AP matches packets transmitted or received to a network name with the associated VLAN. Traffic received by a
VLAN is only sent on the wireless interface associated with that same VLAN. This eliminates unnecessary traffic on the
wireless LAN, conserving bandwidth and maximizing throughput.
In addition to enhancing wireless traffic management, the VLAN-capable AP supports easy assignment of wireless users
to workgroups. In a typical scenario, each user VLAN represents a workgroup; for example, one VLAN could be used for
an EMPLOYEE workgroup and the other for a GUEST workgroup.
In this scenario, the AP would assign every packet it accepted to a VLAN. Each packet would then be identified as
EMPLOYEE or GUEST, depending on which wireless NIC received it. The AP would insert VLAN headers or "tags" with
identifiers into the packets transmitted on the wired backbone to a network switch.
Finally, the switch would be configured to route packets from the EMPLOYEE workgroup to the appropriate corporate
resources such as printers and servers. Packets from the GUEST workgroup could be restricted to a gateway that
allowed access to only the Internet. A member of the GUEST workgroup could send and receive e-mail and access the
Internet, but would be prevented from accessing servers or hosts on the local corporate network.
AP-4000 Series User Guide
114