A communication system using a network route establishing technique for a network having a plurality of nodes connected through links, in which a route search message is delivered simultaneously in a plurality of directions from a sender node through a network route to a destination node, and a confirmation is delivered from the destination through the network route back to the sender node, and accordingly, a network route is established. The communication system includes a device for detecting, at a node through which a search message is to be transmitted, a possibility of a transmission of the search message beyond the node, a device for delivering a cancel message in the direction from which the search message has been transmitted, and a device for releasing the network route engaged by the search message, based on the delivered cancel message.

Communication system using establishing network route

Simulation study of a flood routing technique for mesh-like LANs

ArbNet (arbitrary networks) is a local network architecture with a transmission medium consisting of point-to-point links connected in arbitrary fashion. This network is characterized by high performance and high availability and is robust and amenable to network reconfiguration. An overview of the media access protocol and the interswitch protocol are described, and the results of a simulation study are presented. A comparison of ArbNet's throughput performance with that of Ethernet is carried out. The reliability of the network is discussed. The delay and throughput performance of ArbNet is shown, through simulation, to be dependent on network topology, network size, packet size, and line rate. Its superior performance and lower line rate resemble those of random access LANs. Meshlike ArbNet is also shown to have an aggregate throughput rate of a few times higher than the line rate, and in most cases has a throughput-delay performance superior to that of common-channel LANs, such as Ethernet and token ring. Simulation results show that ArbNet with bus and ring topology perform better than Ethernet. >

ArbNet: a robust and highly configurable local network

A new flood routing protocol for LANs with arbitrary topology is described, and studied by means of simulation modelling. The protocol, marked as T-MAFR, has better performance than the known protocol MAFR, but its implementation is simpler. The results of simulation experiments give the comparison of three LAN protocols: CSMA/CD, MAFRT, and T-MAFR.

One Flood Routing Protocol for LANs with Arbitrary Topology

Comparative performance study of flood routing LANs and a CSMA-CD bus

The lack of satisfactory passive connectors, of standardisation in fibre-optic devices and the unidirectional light transmission employed in most fibre links prohibits the direct translation of networking techniques from the better developed wire or cable systems. A point-to-point network with nodes connected in an arbitrary fashion can provide an ideal solution to these problems while maintaining high network reliability and permitting easy reconfiguration, but has associated problems in the routing of the data. A possible solution is to use the flood routing technique as proposed by Neff and Senzig in their Anarchy network. Unfortunately, this network exhibits very low channel utilisation and has packet looping problems. In the paper we discuss methods of removing the looping problem and then propose a modified Anarchy flood routing (MAFR) protocol, for which a simplified performance analysis and simulation studies indicate that better network performance can be achieved with little additional hardware. However, we believe that a hybrid flood routing scheme (HFR) involving MAFR and a virtual circuit approach will produce a better system.

H.K. Pung

Papers

Fibre-optic local-area network with arbitrary topology