The TCP/IP protocol Suite includes many protocols, as shown in Figure below. Each layer has own working protocol. Application layer protocols included the Domain Name System(DNS), host configuration protocol such as Dynamic Host Configuration Protocol (DHCP) and Bootstrap Protocol (BOOTP), Email protocols (POP, SMTP, and IMAP), file transfer protocol as well as HyperText Transfer Protocol. The Transport Layer included the Transmission Control Protocol (TCP) as well as User Datagram Protocol (UDP). The internet layer working protocols are Internet Protocol (IP), Network Address Translation (NAT), Internet Control Messaging Protocol (ICMP) as well as routing protocol. The Network Access Layer included Address Resolution Protocol (ARP), Point to Point Protocol (PPP), Ethernet and Interface Drives.
The lower layer protocols in the network access layer are responsible for delivering the IP packet over the physical medium. These lower layer protocols have developed by standards organizations, such as IEEE. The Protocol suite is implemented; as a TCP/IP stack on both the sending and receiving hosts to provide end-to-end delivery of applications over a network. The Ethernet protocols are used; to transmit the packet over the physical medium used by the LAN.
TCP/IP Communication Process
1. Host-1 is sending data using Hypertext Markup Language (HTML) page to Host-2.
2. The application protocol HTTP header added to the front of the HTML data as shown in the figure below. The header has a variety of information just like IP header; Ethernet header, TCP header and also HTTP version the server is using; and a status code representing it has information for the web client.
The application layer protocol HTTP forwards the HTML-formatted; web page data to the transport layer (Layer 4 of the OSI Model). The Transport Layer then adds TCP header to the HTTP data and also convert the data into the segment. The transport layer also handles each conversation; in this example between the Host-1 and Host-2.
4. Next, the IP information added to the front of the TCP information and convert the segment to the packet. IP assigns the source and destination IP addresses.
5. The Ethernet protocol adds information to both ends of the IP packet; known as a data link frame. This frame is delivered; to the nearest router along the path towards the web client. This router removes the Ethernet information; analyzes the IP packet; determines the best path for the packet; inserts the packet into a new frame, and sends it to the next neighbouring towards the destination. Each router removes and adds new data link information before forwarding the packet.
At the receiving end, the client receiving the data link frames that contain the data. Each protocol header is processed and then removed in the opposite order it was added. After removing all headers the user received and sees the original data as shown in the figure below.