1. Introduction-11
The following sections describe how deploying VLANs can
benefit organizations and reduce administration costs.
BROADCAST CONTAINMENT
In traditional networks, traffic broadcasts to all network devices,
whether they are the intended recipients or not. However,
VLANs can be set up to contain only those devices that need to
communicate with each other. As a result, VLANs significantly
reduce network congestion. In addition, VLANs prevent
broadcast storms from causing network meltdown due to
volumes of traffic.
MULTICAST-BASED MULTIMEDIA APPLICATIONS
Multimedia applications, such as interactive training, video
conferencing, and news-video transmissions, require large
amounts of bandwidth. These applications are also extremely
sensitive to variable delays, which are unavoidable on a shared
Ethernet network. By defining a VLAN based on the IP multicast
address for all subscribing members on the VLAN, sufficient
bandwidth will be available for these application, providing true
multimedia on Ethernet.
ENHANCED SECURITY
Because VLANs are self-contained, only the devices within the
same VLAN can communicate with each other. If a device in one
VLAN wants to communicate with a device in another VLAN, the
traffic must go through a router.
