A lightweight marker with partial state information for DiffServ networks

A problem common to packet markers used in DiffServ architectures is the provision of Quality of Service to TCP flows: specifically, short-lived TCP flows suffer from packet losses at small congestion windows, which inevitably leads to lengthy retransmission timeouts. It would therefore be sensible to mark packets of short-lived flows so as to offer them a greater level of protection. In this work, we propose a class of Fair Markers that, without the penalty of per-flow management, achieves the same performance enhancement of a per-flow marker, but with a much simpler design and limited implementation complexity. Extensive simulations with realistic traffic scenarios and simple analytical models allow us to compare our proposal with existing ones. We also underline the importance of providing a minimum protection to both data and acknowledgment segments of traffic crossing congested domains.