. A maximum of 16 queues can be built with custom queuing. Each queue is serviced sequentially until the number of bytes sent exceeds the congurable byte count or the queue is empty. One important function of custom queuing is that if SNA trafc uses only 20 percent of the link, MCSE Certification the remaining 20 percent allocated to SNA can be shared by the other trafc.
Custom queuing is designed for environments that want to ensure a minimum level of service for all protocols. In todays multiprotocol internetwork environment, this important feature allows protocols of different characteristics to share the media.
Weighted Fair Queuing
Weighted fair queuing is a trafc priority management algorithm that uses the time-division multiplexing (TDM) model to divide the available bandwidth among clients that share the same interface. In time-divisionmultiplexing, 70-270 Exam each client is allocated a time slice in a round-robin fashion.
In weighted fair queuing, the bandwidth is distributed evenly among clients so that each client gets a fair share if every one has the same weighting. You can assign a different set of weights, for example through type-of-service, so that more bandwidth is allocated.
If every client is allocated the same bandwidth independent of the arrival rates, the low volume trafc has effective priority over high volume trafc. The use of weighting allows time-delay-sensitive trafc to certification provider obtain additional bandwidth, thus consistent response time is guaranteed under heavy trafc. There are different types of data stream converging on a wire, as shown in Figure 2-7.