Introduction

The router performs queuing to handle arriving traffic in such a way that it benefits the organization more than the default configuration does. Queuing can place certain types of traffic ahead of other types when the router decides what packet to route next. This process can be useful when an organization uses protocols that are more sensitive to delay than other protocols. This chapter covers when to use each of the three types of queuing, how to configure the router for each type, and the potential pitfalls.

Queuing is most effective on slow "bursty" links. Generally, these links are WAN serial lines. If a link experiences a small amount of congestion, then traffic queuing might be an option to improve the user's perception of increased traffic throughput. If a link does not ever get congested or is always congested, then it is unlikely that traffic queuing will be of much benefit. A router can establish separate bandwidth allocations for each of the many protocols and types of traffic.