Administration of the Avaya G350 Media Gateway - Avaya Support

Configuring advanced switchingVLAN overviewA VLAN is made up of a group of devices on one or more LANs that are configured so thedevices operate as if they form an independent LAN. These devices can, in fact, be located onseveral different LAN segments. VLANs can be used to group together departments and otherlogical 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 differentlocations and attached to different hubs. In this example, the Management VLAN consists ofstations on numerous floors of the building which are connected to both Device A and Device B.Figure 9: VLAN OverviewIn virtual topological networks, the network devices can be located in diverse places around theLAN. 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, andthe network manager uses management software to assign each device to a virtual topologicalnetwork. Elements can be combined into a VLAN even if they are connected to differentdevices.You can use VLANs whenever there are one or more groups of network users that you want toseparate from the rest of the network.In the following figure, the switch has three separate VLANs: Sales, Engineering, andMarketing. Each VLAN has several physical ports assigned to it with PCs connected to thoseports. When traffic flows from a PC on the Sales VLAN, for example, that traffic is onlyforwarded out the other ports assigned to that VLAN. Thus, the Engineering and MarketingVLANs are not burdened with processing that traffic.132 Administration of the Avaya G350 Media Gateway