We introduce a new,"worst-case"model for an asynchronous communication network and investigate the simplest (yet central) task in this model, namely the feasibility of end-to-end routing. Motivated by the question of how successful a protocol can hope to perform in a network whose reliability is guaranteed by as few assumptions as possible, we combine the main"unreliability"features encountered...

In this report, delay bounds in data flow systems with nonFIFO service disciplines are explored. It is shown that conventional network calculus definitions of a service curve are not satisfying under the assumption of non-FIFO service. Either the definition is too strict to allow for a concatenation and consequent beneficial end-to-end analysis, or it is too loose and thus results in infinite d...

The IEEE 802.6 Standard Distributed Queue Dual Bus (DQDB)for Metropolitan Area Networks (MAN) has been proposed. It is based on a uni-directional twin bus architecture. The DQDB protocol lays more emphasis on the overall channel utilization than the fair sharing of channel bandwidth by all the stations. In this paper, we first describe the unfairness problem in which the upstream stations occup...

Phones are used to confirm some of our most sensitive transactions. From coordination between energy providers in the power grid to corroboration of highvalue transfers with a financial institution, we rely on telephony to serve as a trustworthy communications path. However, such trust is not well placed given the widespread understanding of telephony’s inability to provide end-to-end authentic...

This paper presents an admission control framework for Expedited Forwarding (EF) traf®c in a Differentiated Service Network. The aim is to overcome the limitations, in terms of achievable ef®ciency, which are proper of a deterministic ªworst-caseº approach based on the zero-loss assumption. An admission control procedure is de®ned which provides quanti®able end-to-end QoS guarantees in terms of...

In this paper, we address the problem of guaranteeing end-to-end (ETE) delay of packets in a distributed system where the technique of time division multiplex access (TDMA) is adopted, and the application at the destination node requires to process the packets at a regular rate. We present a time slot allocation algorithm to satisb the transmission rate requirement, and to minimize the scheduli...

Today’s middleware applications tend to be complicated, and consist of tiers that form a nested chain of objects or processes. For a real-time nested application, predictability is crucial, even when faults and restarts occur. Nested applications make it challenging to predict the processing time when faults occurs. The fault-detection and recovery times are influenced by the number of tiers, t...