lgorithm. It is used to provide guaranteed (constant bit rate [CBR]) bandwidth to inputs of any scheduler by assigning them 22-bit weights. The concepts and distinction between work-con- serving and non-work-conserving algorithms are thoroughly discussed in several good computer- network theory books, such as An Engineering Approach to Computer Networking: ATM Networks and the Telephone Network by Srinivasan Keshav.2 Excess bandwidth weighted fair queuing (EB-WFQ) With this algorithm, each input to a sched- uler is assigned one of 32 possible 22-bit weights. Bandwidth is served to the nonempty inputs rel- ative to these weights. The WFQ algorithm distributes bandwidth proportionally to the weights, even in the presence of variable-length packets. Frame-based deficit round robin (FBDRR) This algorithm, which is only available for use with the level 3 schedulers, apportions the bandwidth according to the weights that have been assigned to traffic queues. The FBDRR variant of the well-known deficit round robin (DRR) algorithm uses a configurable service quantum to reduce the latency and jitter, which are intrinsic to the funda- mental DRR approach. The Motorola Q-5 TMC practices what one would call Active Queue Management (AQM). The combination of a flexible buffer-sharing scheme at flow, class, and interface levels enables a wider regime of operating conditions when confronted with traffic congestion without any significant degra- dation of QoS levels associated with flows or connections. The traffic-payload descriptors are stored once they are received. The Q-5 TMC forwards them to the appropriate destination only when it must transmit them-something that it does as part of the scheduling operation. This information is stored internally in a descriptor buffer. The Q-5 TMC supports up to 2 million descriptor buffers, and each one is configurable from 8, 16, 24, to 32 bytes in size. This flexibility enables the dynamic allocation of buffer space and the easy maximization of buffers, which are allocated to active tra