Small Business Networking Goes Virtual

While a LAN may make sense for small networks, it makes expansion or reorganization difficult. Under a LAN setup, all the devices and equipment are located physically near each other and directly connected to a router. In this case, a physically disjointed organization can't use a single network address space. To put users on the same broadcast domain, regardless of physical proximity, the organization needs a VLAN.

For LANs with a lot of broadcast traffic or more than 200 devices, there is an increased chance of packet collisions happening. Packet collisions can cause latency issues within the network. VLANs direct broadcast traffic so that only its group members will see it, not every device connected to the router. This makes sense for groups using an application that is not available to the entire organization, such as VoIP. VoIP users can be assigned to their own VLAN, and the voice traffic will not interfere with other traffic for regular users.

For this TechBuilder recipe, the Channel Test Center redefined an existing LAN to take advantage of VLANs for bandwidth and security purposes. The network, designed to approximate the kind of environment found in small businesses, consisted of several servers, desktops and laptops, all running either Microsoft Windows XP, Windows Vista, or Debian Linux. The LAN included both wired and wireless networks. For this VLAN setup, Test Center engineers used the Netgear Prosafe 48-Port Gigabit Stackable Smart Switch GS748TS.

Netgear is not the only company to make VLAN-capable switches. Cisco's line of Catalyst switches and HP's ProCurve Networking product line also support VLANs. The GS748TS is a stackable smart switch with 48 Gigabit Ethernet ports and four SFP combo fiber ports. Two dedicated ports provide a 20-Gbps, dual-ring, stacking bus to allow up to six switches to be stacked, for a grand total of 288 available ports. The Netgear Prosafe switch includes a suite of robust security features, high quality of service and high availability. It also supports Access Control Lists, 802.1x port authentication, rate limiting and IGMP Snooping. All the devices connected to this switch (and all the stacked switches) can be managed from a single IP address through a comprehensive Web-based management interface.

While creating subnets solves the broadcast traffic problem, all devices on that subnet must be connected to the same switch and that switch must be connected to a port on the router. Under a VLAN configuration, each VLAN is already on its own subnet. Devices in different physical locations, irrespective of which switch (same or different) they are connected to, can be assigned to the same network.

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