3.2.2 Circuit switching, packet switching and routers

In computers, parallel processing is the processing of program instructions by dividing them among multiple processors with the objective of running a program in less time.In other words it is  the simultaneous use of several  processors to perform a single job Four basic computer  architectures are  $ single instruction, single data  (SISD),   $ single instruction, multiple data  (SIMD),  $ multiple instruction, single data  (MISD),  $ multiple instruction, multiple data  (MIMD) Single instruction, single data  (SISD) @    A computer that does not have the ability for parallel processing @ There is only one processor executing one set of instructions on a single set of data.   Single instruction, multiple data  (SIMD) @  The processor has several ALUs. Each ALU executes the same instruction but on different data. Multiple instruction, single data  (MISD) Multiple instruction, multiple data  (MIMD) @  There are several processors. Each processor executes differe

Differences   :  RISC Vs CISC • RISC has fewer instructions // CISC has more instructions • RISC has many registers // CISC has few registers • RISCs instructions are simpler  // CISC’s instructions are more complex • RISC has a few instruction formats // CISC has many instruction formats • RISC usually uses single-cycle instructions // CISC uses multi-cycle instructions • RISC uses fixed-length instructions  // CISC uses variable-length instructions • RISC has better pipelineability  // CISC has poorer pipelineability • RISC requires less complex circuits // CISC requires more complex circuits • RISC has fewer addressing modes  // CISC has more addressing modes • RISC makes more use of RAM // CISC makes more use of cache/less use of RAM • RISC has a hard-wired control unit  // CISC has a programmable control unit • RISC only uses load and store instructions to address memory  // CISC has many types of instructions to address memory • RISC emphasizes on software // CISC em

In computing, a communication protocol refers to the set of rules that computers use to communicate with each other. The protocol defines the signals that the computers will give each other, and other details such as how communication begins and/or ends. The most commonly used protocol on the Internet today is the TCP/IP protocol. Its implementation can be viewed as a stack, with 4 layers where each layer has its own functionality. EACH LAYER OF THE STACK CAN BE IMPLEMENTED AS A SOFTWARE AND BASICALLY, THE WHOLE PROTOCOL IS ALSO A SOFTWARE. Now before discussing the layer of  TCP/IP  protocol,  just have an idea of the OSI model. Actually OSI model, in simple terms, is a standard framework designed to assist the development of a protocol. It has seven layers. Now u can see that some layers of OSI model are combined with other layers and implemented as a single layer in TCP/IP  stack. Click here to understand TCP/IP Functions of layers of TCP/IP protocol Applicat