This paper describes the congestion resolution mechanism adopted in the network interfaces of the 3-Level Integrated Hybrid Optical Network (3LIHON). In 3LIHON, three service levels, namely guaranteed transparent service, real time statistically multiplexed packet service, and best effort basic Internet service are considered. The proposed mechanism is designed to meet Quality-of-Service requirements in future Internet scenarios, when mixing these traffic classes on a generic output node interface. Delay and loss performance obtained with this mechanism are evaluated by asynchronous simulation. Insights in reciprocal influence of traffic integrated on the same interface are reported and discussed for different sample hybrid traffic mixes. In particular loss for real-time traffic can be kept under reasonable values with a proper traffic dimensioning. Furthermore, delays for the best effort class are negligible compared to aggregation and propagation delays. The novel results obtained can be applied to support switch design and quality traffic engineering in hybrid networking.
