Vlan Overview - Avaya G250 Administration

Configuring advanced switching

VLAN overview

A VLAN is made up of a group of devices on one or more LANs that are configured so the
devices operate as if they form an independent LAN. These devices can, in fact, be located on
several different LAN segments. VLANs can be used to group together departments and other
logical groups, thereby reducing network traffic flow and increasing security within the VLAN.
The following figure illustrates how a simple VLAN can connect several endpoints in different
locations and attached to different hubs. In this example, the Management VLAN consists of
stations on numerous floors of the building which are connected to both Device A and Device B.
Figure 24: VLAN Overview
In virtual topological networks, the network devices can be located in diverse places around the
LAN. These devices can be in different departments, on different floors, or in different buildings.
Connection is achieved through software. Each network device is connected to a switch, and
the network manager uses management software to assign each device to a virtual topological
network. Elements can be combined into a VLAN even if they are connected to different
devices.
You can use VLANs whenever there are one or more groups of network users that you want to
separate from the rest of the network.
In the following figure, the switch has three separate VLANs: Sales, Engineering, and
Marketing. Each VLAN has several physical ports assigned to it with PCs connected to those
ports. When traffic flows from a PC on the Sales VLAN, for example, that traffic is only
forwarded out the other ports assigned to that VLAN. Thus, the Engineering and Marketing
VLANs are not burdened with processing that traffic.
220 Administration for the Avaya G250 and Avaya G350 Media Gateways