KNOW INTERNET PROTOCOL ( TCP/IP )

In order for this intrenet network should have to apply the standard rules that govern them there because it needed an internet protocol.
History of TCP / IP
Internet Protocol was first developed by the Defense Advanced Research Projects Agency (DARPA) in 1970 as the beginning of an effort to develop a protocol that can interconnect a variety of separate computer networks, each network uses different technology. The main protocol that generated this project is the Internet Protocol (IP). The same research that is
developed also some high-level protocol that is designed to work with IP. The most important of these projects is the Transmission Control Protocol (TCP), and all the protocol groups is replaced with TCP / IP suite. The first TCP / IP implemented in the ARPANET, and began to develop after the University of California at Berkeley began to use TCP / IP with the UNIX operating system. Apart from the Defense Advanced Research Projects Agency (DARPA) is developing an Internet Protocol, which also developed the TCP / IP is the Department of Defense (DOD).
The terms in the Internet Protocol
There are several terms that are often found in discussion of the TCP / IP, some of them:
Host or end-system, a customer at the service communications network. Hosts are usually in the form of individual workstations or personal computers (PCs) where the duties of the host is usually a running application and server software program that functions as a user and executing a communications network service.
Internet, which is a set of network (network of networks) a thorough and using TCP / IP to connect, such as virtual networks.
Node, is the term applied to the router and host.protocol, which is a standard procedure or rules for defining and setting the data transmission between computers.
Routers, devices that are used as a liaison between two or more networks. Different from the host router because a router usually is not a goal or data traffic. Routing of IP datagram is usually done with software. So routing functions can be performed by a host who has two or more networks connection.
Overview of TCP / IP
As noted above, the TCP / IP is also developed by the Department of Defense (DOD). DOD has conducted a research project to connect several networks designed by different vendors to be the networks of networks (internet). At first it worked because it only provides basic services such as file transfer, electronic mail, remote logon. Several computers in a department can use TCP / IP (along with other protocols) in a single LAN. IP component provides routing from the department to the enterprise network, then to regional networks and finally to the global Internet. This can make the network communication can be broken, so to overcome it, so then DOD designing TCP / IP that can be improved with the automatic if any node or phone line failure. The result of this design makes it possible to build very large networks with less central management. Because of the automatic repair the problem in the network is not checked and not repaired for a long time.
Like other communication protocols, the TCP / IP also has several layers, layers are:
=> IP (internet protocol) that play a role in the transmission of data packets from node to node. IP precedes each data packet based on 4 bytes (for IPv4 version) destination address (IP number). Internet authorities created a range of numbers to different organizations. Organizations to create a group with the number of the department. IP works on gateaway machine that move data from department to organization to region and then later to the whole world.
=>TCP (transmission transfer protocol) contribute in improving the delivery of correct data from a client to the server. Data can be lost in the middle of the network. TCP can detect errors or lost data and then perform retransmission until the data is received correctly and complete.
=> Sockets is a name given to the package subroutines that provide access to TCP / IP on most systems.

But some important things in the TCP / IP
1. Lowest Requesting Network (Network of lowest bidders)
IP developed to create a network of networks (internet). Individual machine connected to the LAN (Ethernet or Token Ring). TCP / IP LAN to share with other users (Novell file server, windows etc). Devices provide a TCP / IP link between the LAN and the outside world.
To ensure that all types of systems from different vendors can communicate, then the use of TCP / IP standardized on the LAN. Mikroprossesor with increasing speed, fiber optics, and digital phone lines will have created some new technology options that include ISDN, frame relay, FDDI, Asynchronous Transfer Mode (ATM).
Original design of TCP / IP is a network of networks that match the current use of technology. TCP / IP data can be sent via a LAN, or can be brought to an internal corporate SNA network, or data can be connected to the TV cable. Furthermore, the machines are connected on one network can communicate with other networks through gateways provided by the network vendor.

2. Addressing Problems
In an SNA network, every machine has Logical Units with each network address. DECnet, Appletalk, and Novell IPX has a plan to make the numbers for each local network and for each workstation that is connected to the network.
In addressing the main part of the local network, TCP / IP makes a unique number for each workstation in the entire world. IP number is the value of 4 bytes (IPv4) with alter convention each byte into a decimal number (0 to 255 for the IP that is used now) and separates the bytes with a period. For example 130.132.59.234.
An organization started by sending electronic mail to Hostmaster@INTERNIC.NET asking for the manufacture of network numbers. It is possible for almost anyone to get the number for the network of "small class C" with the first three bytes and bytes of network meyatakan final states of individual computers. Larger organizations can obtain the network of "Class B" with the first two bytes and two networks declared declared declared last bytes of each individual workstation until it reaches 64 000 workstations. Examples of Class B Network Yale is 130 132, so all computers with IP addresses 130 132 .*.* is connected through Yale.
Then the organization associated with the intenet through one of several regional networks, or a special network. given network vendor networks and subscriber numbers are added to the routing configuration within each engine.
There is no mathematical formula that converts the number 130 132 192.35.91 or a "Yale University" or "New Haven". Machines that regulate large regional network or Internet routers can determine the location of the center of these networks by searching for each network number in the table. It is estimated that there are thousands of networks and millions of class B class C network Customers who connect to the Internet, even big companies like IBM do not need to maintain information on network-jatingan another. They send all the external data into a regional carrier for their customers, and regional carriers to observe and maintain routing tables and doing the right.

3. Subnets
Although individual customers do not need a table number or provide explicit routing network, but for most class B network can be set internally, so a smaller version and a simpler network organization. Usually divide the two bytes into one byte of internal assignment department number and one byte Workstation ID.
Enterprise network is built using TCP / IP router box commercial. each router has a table with 255 entries to change one byte number of departments become the choice destination ethernet that is connected to a router. For example, a message to the 130.132.59.234 through regional networks under the National and New England 130 132 part numbers. Arriving at Yale, 59 department ID select ethernet connector. 234 choose a particular workstation on the LAN. Yale network should be updated as new ethernet and departments are added, but was not influenced by changes in engine displacement from outside or within the department.

4. Indeterminate lines
Each time a message arrives at an IP router, the router will make a decision where to next message will be sent. There is the concept of a specific time with preselected path for all traffic. Suppose a company with facilities in New York, Los Angeles, Chicago and Atlanta. Network can be made from four telephone lines to form a loop (NY to Chicago to LA to Atlanta to New York). A message arrives at the router can go NY to LA via Chicago or through Atlanta. can answer back to another street.
How a router can make a decision between a router with a router? there is no right answer. Traffic can be mapped with the algorithm "clockwise" (go to NY to Atlanta, LA to Chicago). Router can determine, send a message to Atlanta then to Chicago next to. Better routing is to measure traffic patterns and sends data through the least busy link.
If one phone line into a single network is damaged, messages can still achieve its goals through other channels. After losing the path from NY to Chicago, the data can be sent from NY to Atlanta to LA to Chicago. That way, the path will continue despite the loss of performance decline.
Improvements such as these are additional sections on the design IP.

5. Not Checked problems (undiagnosed Problem)
If any errors occur, the network reported to authorities. These errors must be justified or corrected. IP, is designed to be durable and strong. Lost node or line is a normal thing, but must keep the road network. So configure IP automatically reset itself if there is something wrong. If a lot of redundancy built into the communication system remained in place and intact. TCP is designed to recover a failed node or channel where the propagation of routing table changes to all router nodes. Because the updating process requires a long time, TCP bit slow to initiate recovery.

6. Regarding the IP Number
Every large company or university that is connected to the Internet must have an intermediate level networks. some routers may be configured to connect to LAN bebarapa department. All traffic outside the organization associated with a single connection to a network of regional providers.
Thus, the end user can install TCP / IP on your PC without having to know the regional network. Three pieces of information required:
=> IP address is created on your PC
=> Part of the IP address (subnet mask) that distinguishes other machines in the same LAN (messages can be sent directly) with the machines in other departments atao anywhere in the world (that is sent to the router machine)
=> IP address of the router machine that connects the LAN to the outside world.

7. The composition of the TCP / IP protocol
Internet was originally designed with two main criteria. Two of these criteria are influenced and shaped hardware and software that is used now. These criteria: Networks must perform communication between researchers in different parts of the world, allowing the They can share and communicate about their research with one another. Unfortunately, research requires a variety of different computer platforms and different network architectures for scientific purposes. So it is necessary for the protocol suite to be associated with a variety of different hardware platforms and even different network systems. Furthermore, the network should be a strong communications network that has the ability to survive a nuclear attack. This design memebawa toward decentralized network consisting of a network of separate, smaller, isolated network that has the ability automatically when needed.
Abstrsaksi level layer provides software and increase the ability to reuse and platform independence. Layers are meant to truly separate from one another and also independent. Layer does not rely on detailed information from other layers. Architectural design makes it easier to do maintenance because the layer can be redesigned or developed without destroying the integrity of the protocol stack.
TCP / IP protocols suite consists of four layers: Application, Transport, Internetwork, and network interfaces. Layer can be seen as a hierarchy like below:
Application Layer is an application that sends data to the transport layer. For example FTP, email programs and web browsers.
Transport Layer is responsible for communication between applications. This set the channel layer may provide additional information and error checking. Data is divided into several packets sent to the internet layer with a header. The header contains the destination address, source address, and checksum. Checksum is checked by the recipient's machine to see if the package is missing on the route.
Internetwork layer responsible for communication between machines. This layer-engcapsul meg package from the transport layer in IP datagrams and routing algorithm to determine where datagaram should be sent. The inclusion of a datagram is processed and inspected kesahannya before passed on Transport layer.
Networks interface layer is the lowest level of the order of the TCP / IP. This layer is the device driver that allows datagaram IP sent to or from the physical network. Dapaat the form of a cable network, Ethernet, frame relay, Token Ring, ISDN, ATM networks, radio, satellite or other device that can transfer data from system to system. Network interface is an abstraction layer that facilitates communication between the multitude network architecture.