IPIQ: Installer Tips: Add Value to Your Next Network Installation with VLANs
The ability to optimize IP network and application performance is an essential skill for any installer. Depending on the customer’s network usage and application requirements, VLANs (Virtual Local Area Networks) may be a valuable part of a high-performance network setup. Knowing how and when to implement VLANs can help set you apart from the competition and improve the customer’s IP networking experience.
1) What is a VLAN and what does it do?
A VLAN is a way of dividing a physical device (for instance, a managed switch) into two or more logical Broadcast Domains—or basically making it appear as more than one switch on the network in order to isolate different types of traffic or applications from each other and improve network performance. The term “Logical” is used to describe the fact that there is only one physical device, but it is being divided in such a way as to create multiple devices independent of each other. The division of the Physical device is accomplished using VLANs as illustrated in Image 1:
A Broadcast Domain is any Layer 2 device (such as a switch or access point) that passes broadcast requests to all devices to which it is connected. All Layer 2 devices have a Broadcast Domain with all broadcast packets being sent to all connected devices within the domain. If not properly managed, this can have a significant limiting effect on the network and application performance, especially when dealing with latency sensitive systems such as VoIP, Media Streaming or database connections. In these cases, VLANs can be used to limit the broadcasts on the Broadcast Domain to only the specified VLAN members, thus optimizing network traffic and improving network performance. Another benefit of VLANs is that they improve security within the network by isolating traffic and applications. It is important to note that VLANs on a Layer 2 device cannot communicate with each other.