Electerical Engineering, Ferdowsi University of Mashhad
In Local Area Networks (LAN) connected together by bridges, flow control and smooth traffic in the network is very important. However, congestion at bridges can cause intensive loss of received frames. In addition, the received frames are thrown away and have to be retransmitted by the source station, which causes more congestion and massive reduction in the overall network throughput. The network has a series topology in which all the LANs use Token Ring protocol at the presence of voice and data services. In the simulation voice traffic has the priority to access the network over the data traffic. In this paper techniques are introduced to reduce congestion at the bridges and improve the overall performance in the LANs connected through bridges. In the first technique data transmission is allowed during voice transmission by bridges. In the second technique the bridges have higher priority of access. The results show that using these techniques significantly improves network throughput.