Differentiated services network with distributed-buffer core-stateless weighted fair queuing

Existing bandwidth broker approach for centralized or hierarchical reservation control in differentiated service (DiffServ) network is appropriate for long-lived flows, and requires out-of-band signaling transport mechanism and per-flow state maintenance within the core. While persistent congestion may be minimized with bandwidth broker, transient congestion is unavoidable as per-flow reservation control is not feasible in DiffServ network. This paper proposes a novel distributed-buffer core-stateless weighted fair queuing (DC- WFQ) network architecture to support: (1) a distributed core-stateless reservation control scheme that is appropriate for short-lived and long-lived flows, and does not require the support of an explicit signaling transport mechanism; (2) a transient congestion control scheme to prevent packet loss by absorbing transient congestion with distributed buffering in upstream routers associated with the potential congestion-causing traffic. The proposed DC-WFQ network is based on extension and DiffServ adaptation of the core-stateless fair queuing (CSFQ) network, which is enabled with dynamic packet state encoding and probabilistic packet dropping to approximate fair queuing among flows. The CSFQ network is adapted to support weighted fair queuing among flow-aggregates.