Cisco IOS supports the following queuing methods:
1. Weighted fair-queuing: This is an automatic queuing method that provides fair
bandwidth to all network traffic.
2. Priority queuing: In this type of queuing, one particular type of traffic is given
priority over all other types of traffic. Thus this particular traffic, for which priority is given is assured of getting through. All other types of traffic may not get through in a timely manner.
3. Custom queuing: Here, each traffic type gets a pre-allocated bandwidth. Certain types of traffic can be allocated higher bandwidth depending on the need.