the workings of TCP / IP

TCP / IP is a data communication protocol model gives a very large change in the world of communications and computers. TCP / IP protocol is to provide an internationally recognized standard and is used as a reference in the development of the computer world, especially on computer networks. Where this protocol can provide flexibility in communication between one computer with other computers in a network even if the computer uses a different operating system platforms. TCP / IP has five layers. Unlike the OSI model has seven layers. The layers include Physical Layer, Network Access Layer, the Internet Layer, Transport Layer and Application Layer. The fifth layer has the functions and responsibilities of each as well as the existing layer in the OSI model.Chapter

1. Introduction Background In the process of data communication between computers over the Internet requires a protocol, which is a collection of rules that govern the process of communication between electronic devices, one of which TCP / IP (transmission known as Internet protocol). TCP / IP is a protocol suite that is used to send data between computers in a network without the limitations of hardware and software. This protocol can be used as a means of sending data or control information via computer networks. Internet protocol (IP), User datagram protocol (UDP) and Transmission Control Protocol (TCP) is the basis for network-based communication. TCP / IP originated from the 2 protocols, ie TCP and IP. Communication TCP / IP provides a simple interface, although actually very complex. The use of function TCP / IP contained in the palette Function, Communication, TCP. As with DAQ (data acquisition), instrumentation and communication using port I / O, the process begins by opening a connection, read and write information and ends with a close connection. In most communication uses I / O ports, the processor always start with a connection to the server disk drives, servers external instrument or DAQ server. With TCP / IP, Computers can function as a client or server.Chapter 2. Supporting Theory History of TCP / IPHistory of TCP / IP commencement of the birth of the ARPANET packet switching network is digital which is funded by DARPA (Defense Advanced Research Projects Agency) in 1969. While the ARPANET continued to increase in size so that the protocol used at that time can no longer accommodate the number of nodes that are more and more. Therefore, DARPA funded the manufacture protocol2communication more generally, namely TCP / IP. He was adopted into the standard ARPANET in 1983. To facilitate the conversion process, DARPA also funded a project that implements this protocol into the BSD UNIX, so began the marriage of UNIX and TCP / IP. At first the internet is used to indicate networks that use Internet protocol (IP) but the network develops further, the term is now a generic term used for all classes of networks. Internet used to refer to communities worldwide computer network which interconnected by TCP / IP. The development of TCP / IP is widely accepted and practically become defacto standard computer network related to the characteristics contained in the protocol itself which is keunggulun of TCP / IP, namely: The development of TCP / IP uses an open protocol standard that is widely available. Everyone can develop software to be able to communicate using this protocol. This makes use of TCP / IP spread very quickly, especially in terms of adoption by the various operating systems and network applications. Does not depend on the hardware or operating system specific network so that TCP / IP suitable for various kinds of networks together, eg Ethernet, token ring, a dial-up line, X-25 net and others. Addressing mode is unique on a global scale, enabling the computer to uniquely identify the other computers in the entire network, even though its network of worldwide Internet network. Every computer connected to the network TCP / IP (Internet) will have the address that belongs only to him. TCP / IP routing has the facilities and types of other services that allow applied to the internetwork.Architecture and Network Protocols TCP / IPIn a computer network architecture, there is a layer-layer (layer) that has a specific task and has its own protocol. ISO (International Standards Organization) has issued a standard for computer network architecture known as the Open Systems Interconnection (OSI). This standard consists of 7 layers of protocols that perform the function of communication between 2 computers. In the TCP / IP only have 5 layers as follows: Figure 1.1 TCP / IP Layer Although the numbers vary, but all the functions of the layers of the OSI architecture are covered by the architecture of TCP / IP. The details of the function of each layer architecture of TCP / IP is as follows: Physical Layer (physical layer) is the lowest layer that defines the physical quantity such as media communication, voltage, current, etc.. This layer can vary depending on the medium of communication on the network that bersangkutan.TCP / IP is flexible so it can integrate various tissues with physical media is different. Network Access Layer has a function similar to the OSI Data Link layer. This layer manage the distribution of data frames of data on physical media used reliably. This layer usually provide service for the detection and error correction of transmitted data. Some examples of protocols used in this layer is X.25 public networks, Ethernet for networking Etehernet, AX.25 Packet Radio network etc.3Internet Layer defines how the relationship can occur between two parties who are on different networks such as the Network Layer of OSI. On the Internet network consisting of tens of millions of hosts and hundreds of thousands of local network, this layer served to ensure that a packet is sent to find the goal wherever located. Therefore, this layer has a particularly important role in realizing internetworking covering large areas (worldwide internet). Some of the important task at this layer are: Addressing, which complement each datagram with the Internet address of the destination. Addresses on this protocol known as Internet Protocol Address (IP Address). Because addressing (addressing) on ​​a TCP / IP is at this level (software), then the TCP / IP network independent of media type and the computer used. Routing, which determines to which datagrams will be sent in order to achieve desired goals. This function is the most important functions of the Internet Protocol (IP). As the protocol is connectionless, the routing process is completely determined by the network. The sender has no control over the packet it sends in order to achieve the goal. Routers on the network TCP / IP is a very decisive in delivering a datagram from the receiver to the destination.Transport Layer defines the ways to perform data transmission between end to end in a reliable host. This layer ensures that information received at the receiver side is the same as the information transmitted to the sender. Therefore, this layer has several important functions including: Flow Control. Delivery of data that has been broken into these packages should be arranged in such a way so that the sender not to transmit data at speeds that exceed the ability of recipients in receiving data. Error Detection. The sender and receiver also completed with some information that could be used to examine the data that is sent free of errors. If you find errors in the received data packet, then the recipient will not receive the data. The sender will resend data packets that contain errors earlier. However, it can cause a significant delay.In the TCP / IP, the protocol used is the Transmission Control Protocol (TCP) or User Datagram Protocol (UDP). TCP is used for applications that require reliability of data, while UDP is used for applications that require short-length packets and does not require high reliability. TCP has a function of flow control and error detection and is connection oriented. In contrast to the UDP which is connectionless no checking mechanisms and data flow control, which is also called unreliable UDP protocol. For some matters relating to efficiency and simplification, some applications choose to use UDP as transport protocol. An example is a database application which is merely a query and response, or other applications that are sensitive to delay, such as video conferencing. Such applications can tolerate a bit error (picture or sound can still be understood), but would be uncomfortable to be seen if there is a significant delay. Application Layer is the last layer in the architecture of TCP / IP that serves to define the applications that run on the network. Therefore, there are many protocols in this layer, in accordance with the number of TCP / IP applications that can run. Examples are SMTP (Simple Mail Transfer Protocol) for sending e-mail, FTP (File Transfer Protocol) to transfer files, HTTP (Hyper Text Transfer Protocol) for web applications, NNTP (Network News Transfer Protocol) for distribution and other news group other. Each application typically uses TCP and IP protocols, so the whole family is named with the protocol TCP / IP.4Chapter 3. Research Methodology The methodology of writing of this article is to use a method based on literature-literature that supports. Chapter 4. Discussion on How to KerjaTCP / IP layers and protocols contained in the architecture of TCP / IP describes the functions in communication between two computers. Each layer receives data from the layers above or below it, then processes the data according to the functions of its protocol and forward it to the next layer. When two computers communicate, the flow of data between sender and receiver through the layers above. At the sender, the data flow is from top to bottom. Data from the user and an application submitted to the Transport Layer in the form of packets with a certain length. Protocol adds a number of bits in each packet as a header that contains information about the sequence of segmentation to maintain data integrity and pariti bits for error detection and correction. From the Transport Layer, which has given the header data is forwarded to the Layer Network / Internet. In this layer by an additional header by the protocol, which provides the destination address, sender address and other information needed to perform routing. Then came the direction of routing data, ie to the network and the interface where the data will be sent, if more than one interface on the host. In this layer can also occur segmentation data, because the length of the package to be delivered must be adapted to the conditions of communication media on the network to be traversed. The process of data communication in the above can be explained as shown below: Figure 1.2 Inter-Process Communication Data Layer Further data to the Network Access Layer (Data Link) where the data will be processed into frames, add reliability and address information at the level of the link. Protocols at this layer to prepare data in a form most suitable to be sent via a specific communication media. Finally the data will arrive at the Physical Layer which will transmit data in the form of magnitudes electrical or physical, such as voltage, current, radio waves or light, according to media used. At the receiver, the data processing is similar as above only in the opposite sequence (from bawqah to top). Signals received at the physical layer will be converted in to the data. Protocol will check its integrity and if not found error t header that is added will be removed. Furthermore, data transmitted to the network layer. In this layer, the address of the packet data received will be checked. If the destination address is the address of the host in question, then the network layer header will be removed and the data will be forwarded to the layer above it. But if not, the data will be forwarded to the network destination, in accordance with routing information held. At the Transport layer, the truth of the data will be checked again, using the header information sent by the sender. If no errors, packets of data received will be rearranged according to the order at the time will be sent and forwarded to the application layer at the receiver.The process is carried out each layer is known as data encapsulation. Encapsulation of this nature transparent. That is, a layer does not need to know how many layers there are in5above or below it. Each one is only doing his job. At the sender, this task is to receive data from the layer above it, processing such data in accordance with the protocol functions, add header protocol and continue to layer underneath. At the receiver, this task is to receive data from the layer underneath, to process data according to the protocol functions, removing the header protokoll and continue to layer on top.