Almost all networks are dependent and rely on TCP/IP because of its reliability and how it acts as the glue to hold systems together. Due to its universal acceptance, programmers use it as the lingua franca of all communications in the network.
Modern computing applies the use of the Internet. Payment processing, online business transaction, chat, email, and etc. require the use of the Internet and are very common practices today. Do you know how your computer is able to access the Internet? For computers to communicate and understand each other, a standard implementation should be used which is the Transmission Control Protocol/Internet Protocol. This is the basic form of communication that allows computers over Internet to exchange information. The Internet is composed of millions of computers connected to each other through networking devices. Before we take a look at some basic principles and theories used in computer networking, let us first get ourselves familiarized with some terms that we will need as we continue reading.
Before reaching the destination, packets have to pass through several layers or protocols in order for the recipient to properly interpret the packets that are sent. TCP is responsible for breaking the message into several packets to be sent over the Internet while on the receiving computer, the TCP then reassembles these packets to from the original message. The IP on the other hand is responsible for providing the proper address of the destination known as the IP Address.
Every computer that runs a TCP/IP must have a network card, each with its own unique IP address. These IP addresses are uniquely assigned to each computer and are giving addresses such as 190.172.0.109. Two parts deal with identifying the IP address. The network ID identifies what hosts are on the same physical network and a host ID is simply the identification of a host on the network. These too parts within the IP address are given specific numbers. In this address, 190.172.0 is the network ID and 109 is the ID of the host.
To divide a larger network into multiple networks connected with routers, you must configure the Subnet Mask which is responsible for blocking out some of the IP addresses so the TCP/IP can be divided and distinguished on the network ID, separate from the host ID. When the subnet mask is configured to do this, it determines when the TCP/IP hosts try's to communicate and if its destination is on the local network or possibly a remote network. In order to communicate on the local network, the network address must be defined by the subnet mask for computers to communicate with it.
Host-to-Host Transport layer provides the end-to-end connectivity of two devices that are communicating. This layer handles the Time-To-Live (TTL) for every connection. TTL is the considerable amount of time given to a packet before it is discarded. If a packet stays to long before being accepted by the recipient and has reached the TTL, it will then be discarded while requesting the sender to resend the packet. Protocols such as TCP and UDP are used in this layer.
DoD reference model defines four layers to pass before a message can be sent. These layers include Application, Host-to-Host Transport, Internetwork, and Network Interface. Open Systems Interconnection (OSI) model is another protocol stack in computer networking that is composed of seven layers. These layes include: Application, Presentation, Session, Transport, Network, Data-Link, and Physical Layer. Each layer has something to do in order to proceed to the next step. Let's focus on the DoD reference model.
Every computer that runs a TCP/IP must have a network card, each with its own unique IP address. These IP addresses are uniquely assigned to each computer and are giving addresses such as 190.172.0.109. Two parts deal with identifying the IP address. The network ID identifies what hosts are on the same physical network and a host ID is simply the identification of a host on the network. These too parts within the IP address are given specific numbers. In this address, 190.172.0 is the network ID and 109 is the ID of the host. To divide a larger network into multiple networks connected with routers, you must configure the Subnet Mask which is responsible for blocking out some of the IP addresses so the TCP/IP can be divided and distinguished on the network ID, separate from the host ID. When the subnet mask is configured to do this, it determines when the TCP/IP hosts try's to communicate and if its destination is on the local network or possibly a remote network. In order to communicate on the local network, the network address must be defined by the subnet mask for computers to communicate with it.
