Smart box architecture

Fundamentally the IP-based networking is designed for delivering data traffic with best-effort service, thus it is not capable of providing end-to-end QoS. Several architectures have been proposed for providing QoS in the Internet: The integrated services (Intserv) model is based on reservations and can provide QoS, however; it is not scalable. The differentiated services (Diffserv) approach is scalable but falls short of ensuring deterministic guarantees --in particular for the services that belong to the same class. Finally, the multi protocol label switching (MPLS) architecture provides mechanisms for QoS-based routing but does not have the necessary resource management and scheduling support to ensure it.

This work proposes a hybrid solution which combines the best of these technologies. First, at the network boundary Diffserv like Service Level Agreements (SLA) are provided to users by intelligent edge routers called the SBoX servers. An SBoX server uses Class Based Queuing (CBQ) with a hierarchy of flow aggregation. At the top a commodity-flow is defined for the aggregate flow between a pair of egress points. The packets of the same commodity-flow are marked by an MPLS label, which is globally unique within an Autonomous System (AS). Each commodity flow is partitioned to a set of macro-flows which are offered to users as SLAs. An SBoX server manages macro-flows and commodity flows only, and leaves the management of each macro-flow (at the micro-flow level based on some policies) to the enterprise/users which signed the SLA. Second, the commodity-flows are managed and supported inside the network by an add-on Label Switching Router (LSR) called the SBoX router which performs MPLS of commodity-flows with CBQ. The main reason for an add on solution is the lack of end-to-end deployment of LSRs, and the vertically integrated architecture of the legacy routers. This paper explains the SBoX architecture and reports experimental results obtained on a prototype network.