Corelite: A quality of service architecture for wireline and wireless networks.

摘要

The convergence of wireless networks and IP networks raises the issue of continuous quality of services (QoS) across wireline and wireless networks. The mobility of a host in the wireless network changes the data path during packet transmission while the current QoS mechanisms in wired networks have assumed a fixed static path. In addition, the fair rate allocation algorithms in current QoS mechanisms have assumed that the aggregate traffic in a link increases continuously as a result of continuous rate adaptation of all the flows. Some types of flows, e.g. layered multicast flows, however, can only perform coarse-grained rate adaptation. The presence of these types of flows invalidates the above assumption of continuous increments of the aggregate traffic, and leads to unfair rate allocation and frequent congestion that eventually causes packet losses, which should be avoided in wireless networks that have relatively low link capacity.; We believe that the integrated QoS architecture for continuous and layered flows in wireline and wireless networks should provide the following rate services. (1) Per-flow end-to-end advance reservation for smooth handoff. (2) Per-flow end-to-end minimum rate assurance for static and mobile flows. (3) Weighted fair rate allocation among flows with different rate adaptation granularity after satisfying the minimum rate contract and advance reservation; In this dissertation, we present Corelite, a QoS architecture that provides both wireline and wireless networks a unified structure for implementing end-to-end QoS assurance without per-flow states in core routers. Corelite is the first QoS architecture that provides an equivalent set of rate services to the wireline and wireless networks in a single framework . It removes the per-flow managing complexity in core routers using soft-state control packets that deliver per-flow state to core routers. The soft-state control packets provide the information so that core routers can foresee the potential increase of the aggregate traffic and allocate the rate to flows without fluctuation.; Because of soft-state control packets delivering per-flow QoS requirements, and the stateless core routers equipped with a look-ahead fair rate allocation scheme, Corelite provides Intserv-like rate services to a diverse class of applications, both mobile and static, in a scalable and stable manner.