The topology of an interconnection network can be static or dynamic. Static networks are created point-to-point direct connections which will not alter during implementation. Dynamic networks are applied with switched channels, which are dynamically constructed to connect the communication demand in user programs.
Static Networks − Static networks are used for fixed connections amid subsystems of a centralized system or various computing nodes of a distributed system. Dynamic networks include buses, crossbar switches, multistage networks, which are provide used in shared-memory multiprocessors. Both types of networks have also been applying for inter PE data routing in SIMD computers.
In general, a network is characterized by the graph of a finite number of nodes linked by directed or undirected edges. The number of nodes in the graph is known as the network size.
Node Degree and Network Diameter − The number of edges incident on a node is known as the node degreed. In the method of unidirectional channels, the multiple channels into a node are the ‘in’ degree and that out of a node is the ‘out‘ degree. Thus the node degree is the total of the two.
The node degree reveals the number of I/O ports needed per node and their value of a node. Hence, the node degree should be kept a constant, as small as possible to reduce cost. A constant node degree is very much preferred to get modularity in building blocks for scalable systems.
The diameter D of a network is the maximum shortest path amid any two nodes. The path length is calculated by the number of links visited. The network diameter shows the multiple distinct hops amid any two nodes, thus giving a figure of communication pros for the network. Thus, the network diameter should be as tiny as applicable from a communication method.