Flow identification for supporting per-flow queueing

Over the last several years there has been considerable interest in multimedia communications over the Internet. This paper investigates one of the key technical issues in supporting per-flow queueing-flow identification. We present several hashing-based flow identification approaches and examine their performance and scalability limits with a quantitative analysis and a simulation study with backbone traffic traces. Of the hashing schemes we studied, 32-bit CRC and XOR-folding of the five-tuple demonstrate excellent performance, both on the memory requirement for a collision rate target, and on the number of collided flows on average and in the worst-case. Our findings show that, with hashing-based schemes, it is feasible to implement flow identification at high speeds to support hundreds of thousands of flows with resource reservation