Controlled loops: A new QoS differentiation framework for delay-sensitive OBS networks

This paper introduces a novel QoS differentiation framework for OBS networks. Two different methods are provided and subsequently validated. Particularly, both proposals aim at using controlled loops as deflection routes, which assures an upper bounded number of hops from source to destination. This yields a twofold outcome. First, the insufficient offset time problematic of standard deflection routing under just-enough-time (JET) is solved. Second, excessively long delays due to uncontrolled deflections are avoided. In both methods, the number of allowed loops is proposed as a QoS metric, giving support for class differentiation. This applies to a scenario with heterogeneous traffic demands, each one with different latency and burst loss requirements. The benefits of these proposals are quantified and further compared against existent alternatives by simulations.