Queueing delays on virtual circuits using a sliding window flow control scheme

Abstract

A tandem queue model is developed that models the end-to-end delay behavior in networks that employ sliding window flow control. Messages a r r i v i n g to find the window f i l l e d are assumed to be queued outside the network to await t h e i r turn to enter. The model is analyzed using a hierarchical decomposition method; the key step entails incorporating the fact that the interdeparture process is not exponentially distributed. End-toend delay in v i r t u a l c i r c u i t s can then be obtained by modelling a v i r t u a l route as a tandem queue [ I ] using the method of "adjusted rates."

Nested sliding window protocols with packet fragmentation

“…it is generally true 'hat for a given f. high utilization, high ratio ( '~)/II A and small window size will be the cases with the worst performance, having relative errors from 5% to 10%. This observation matches that of previous studies, (15]. Table 2 compares the actual values for Pi against the values from the approximating queue for the data sets of Table 1.…”

“…Modelling approaches similar to the above are used by Gihr and Kuehn (14l, Varghese, Chou and Nilsson (15), and Schwartz (16]. In Gihr and Kuehn's analysis the characteristics of the physical transmission process are obtained from analysis of a LAN, in a hierarchical model.…”

“…They also consider group arrivals to the sliding window controlled layer, modelling fragmentation from a higher layer. Both (15] and [16] note that the method is not very accurate in the face of group arrivals.…”