Dynamic partitioning: a mechanism for shared memory management

We propose a novel buffer management scheme in order to regulate the individual queue lengths in a shared-memory switch. The primary motivations of our scheme are: (i) provide differentiated allocations to the queues sharing the memory, where the allocations are directly derived from the call admission control (CAC) parameters; (ii) allow for the co-existence of regulated and best-effort traffic achieving high buffer utilization without violating the guaranteed buffer allocations of the regulated connections; (iii) protect well-behaving connections that conform to their allocations from any misbehaviour in other traffic; and (iv) handle deviations in incoming traffic patterns, from the ones assumed by CAC, by distributing unavoidable losses in an equitable manner. The new scheme, which we call dynamic partitioning, achieves all these objectives, and constitutes a first example of a scheme that is highly efficient, derives its parameters directly from CAC, and is also very robust against misbehaviour. The scheme is simple to implement, and therefore amenable for deployment in current high-speed switches. We present the scheme in the context of ATM switches, together with cell level simulations for its validation.