Best-effort Networks Research Articles

Internet applications over native ATM

Current Internet applications cannot take advantage of the variety of service classes offered by ATM networks. This is due to the stacking, without specific scheduling mechanisms, of a best-effort network layer on top of ATM. Simultaneously, few native ATM applications have been written specifically in this networking framework. We propose an architecture for running TCP-based applications over ATM. This architecture relies on the standard TCP protocol and offers at the socket layer the means to specify an ATM traffic contract. This gives an immediate native ATM access to a rich set of familiar applications. It also helps satisfying the increasing need of resource control for Internet applications. We have developed TCP-ONIP (TCP over non-existent IP), a prototype implementation of this approach. The necessary adaptation steps are shown in the case of the Web.

INQIRE: a software approach to monitoring QoS in ATM networks

Unlike traditional best-effort packet networks, ATM networks support a wide range of services by providing a specified QoS on each ATM connection. Currently, QoS can be measured with specialized high-speed testing equipment but their complexity and cost prevent them from wide field use. This article describes the INQIRE project approach based on software for enabling common personal computers (with an ATM network interface card) to function as QoS monitoring stations at the edges of an ATM network. The main objective is to develop a low-cost, off-the-shelf alternative to broadband testing equipment. An INQIRE station, consisting of a PC running the INQIRE application, can actively probe any selected connection and collect sample measurements of the QoS. The monitoring approach is intended to be non-intrusive and work with any ATM network without requiring any modifications to existing ATM switch equipment or interruptions to active services.