Once the administrator has input the IDs, he or she then indicates to which networks or subnetworks the user or application has access and marks where the user falls in the hierarchy of bandwidth and network service priority. Once policies are entered into the management application, they are downloaded onto switches and routers equipped with agents that recognize and enforce the rules. In one camp are those who argue that WAN bandwidth is scarce and expensive, so establishing policies for divvying up rare transmission resources makes a lot of sense. Conversely, they point out, LANs have a glut of inexpensive bandwidth. Va. Yet some users say LANs could benefit from policies now, even before they take on voice traffic.
Different traffic has different levels of importance based on the time of the month.
There's still no guarantee that mission-critical data will get the bandwidth it needs, he says. Stan Christensen, senior network engineer at PeopleSoft, an enterprise resource planning software developer in Pleasanton, Calif., agrees. In an environment where development teams and accounting teams share the same LAN link back to all their resources, this can be a problem, even with gigabit links. Habermann says policies are vital in a LAN with a lot of multicast or broadcast traffic. Without policy, a network interface card would have to look at all traffic to determine which packets it needs to forward to the workstation.