TCP/IP MODEL
- The TCP/IP reference model is the network model used in the current Internet architecture. It was created in the 1970s by DoD (Department of Defense) for use in developing the Internet’s protocols, and the structure of the Internet is still closely reflected by the TCP/IP model. It is considered as the grandfather of the Internet the ARPANET.
- It consists of four layers.
- It was named after
two of its main protocols , TCP(Transmission Control Protocol) and IP(Internet
Protocol).
- The TCP/IP Model is
basically a shorter version of OSI Model.
TCP/IP Model Layers :
1. Application Layer
2. Transport Layer
3. Internet Layer
4. Network Access Layer
The TCP/IP Protocol Suite :
Layer
4 – Process Layer or Application Layer:
This is the Top layer in which the protocols like FTP,TELNET,SMTP, DNS, DHCP are
operate.
- · Telnet is a program that supports the TELNET protocol over TCP, TELNET is a general two-way communication protocol that can be used to connect to another host and run applications on that host remotely. Port Number of TELNET is 23.
- · FTP(File transfer Protocol) is a protocol that was originally designed to promote the sharing of files among computer users. It shields the user from the variations of file storage on deferent architectures and allows for a reliable and efficient transfer of data. Port Number of FTP is 20 and 21.
- · SMTP (Simple Mail transport Protocol) is the protocol used to transport electronic mails. Port Number of SMTP is 25.
- · DNS (Domain Name System) resoles the numerical address of a network node into its textual name or vice-versa. It would translate https://www.google.co.in/ to 74.125.236.144 to allow the routing protocols to find the host that the packet is destined for. Port Number of DNS is 53.
- ·
DHCP(Dynamic Host Configure
Protocol) is a protocol that
provide the automatic ip addresses to the hosts connected to the server
(configured with dhcp server). Port Number of DHCP is 67,68.
Layer 3 – Host-To-Host (Transport) Layer:
In this layer flow-control and connection protocols
exist, such as TCP , UDP. This layer deals with opening and maintaining
connection, ensuring that packet are in fact received the transport layer is
the interface between the application layer and the complex hardware of the
network it is designed to allow peer entities on the source and destination
hosts to carry on conversations. Data may be user data or control data.
Two modes are available,
Two modes are available,
· Full-duplex
· Half duplex.
In full-duplex operation, both sides can transmit
and receive data simultaneously, whereas in half duplex, a side can only send
or receive at one time.
Layer 2 – Internet or Internetworking Layer:
This layer defines IP addresses, with many routing
schemes for navigating packets from one IP address to another. The job of the
network layer is to inject packets into any network and have them travel
independently to the destination. The layer defines IP (Internet Protocol) for
its official packet format and protocol. Packet routing is a major job of this
protocol.
Layer 1 – Networking Access Layer:
In this layer the physical equipment are exits, such as twisted pair
cables. Host-to-Network layer interfaces the TCP/IP protocol stack to the
physical network. The TCP/IP reference model does not specify in any great
detail the operation of this layer, except that the host has to connect to the
network using some protocol so it can send IP packets over it.
Made BY: P & V
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