Computational Problems in Science and Engineering by Nikos Mastorakis Aida Bulucea & George Tsekouras

Author:Nikos Mastorakis, Aida Bulucea & George Tsekouras
Language: eng
Format: epub
Publisher: Springer International Publishing, Cham

ρ = 0. 80, b 1 = 73, b 2 = 40, b 3 = 42, s

12.5 Controlling the Throughput Using the Work Phase Duration

Similarly, we can obtain a predefined throughput manipulating the work phase. However, this is different than manipulating the buffer size, because changing the work phase of one virtual link we change also the whole cycle, thus influencing the performance of other virtual links in an uncontrolled way. (This does not happen when we change the buffer size.)

Moreover, the dependence of the throughput on the work phase duration can be very irregular. For instance, in Figs. 12.2, 12.3 and 12.4, the dependence of the throughput of virtual links 1, 2 and 3 on the work phase for ρ = 1 is depicted, respectively. Even in the case of simple distribution of the packet size, like in Figs. 12.2 and 12.3, the curve is highly variable and non-monotonic. It has an “increasing” part for short work phases, a “flat” part, and a “decreasing” part for long work phases. Moreover, the general shape is disturbed by a high-scale sawtooth-like irregularities, a middle-scale irregularities (see Fig. 12.2 around buffers sizes 45 and 90). This gets even more complicated, when the packet sizes are distributed, as in Fig. 12.4—now the sawtooth have irregular heights. Moreover, the maximum possible throughput is below 100 % and barely reaches 95 %. This is connected with the the bandwidth loss at the end of the work phase—large packets are blocked because there is not enough time to transmit them within the current work phase and the physical link is idle.

Fig. 12.2The throughput of link 1 versus its work phase duration (in microseconds). ρ = 1, b 1 = 50,

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.