TCP/IP PROTOCOL SUITE

TCP/IP PROTOCOL SUITE

TCP/IP protocol Suite has four layers: Physical Layer, Network Layer, Transport Layer and Application Layer. The Application Layer of TCP/IP protocol Suite is similar to the Application, Presentation, Session Layer of OSI reference model. The handling of Transport Laye in both model are same and services of Network Layer in both model are also identical. The Physical Layer of TCP/IP protocol Suite is combination of Physical and Data Link Layer of OSI reference model.

PHYSICAL LAYER

Physical Layer is also known as Interface Layer and responsible for handling hardware like, transmission line, connection points etc and also for media channel controlling, frame format etc.

NETWORK LAYER

Network Layer is also known as Internet Layer. It  is a strategic layer in the TCP/IP protocol suite. This layer supports IP protocol. IP protocol is responsible for format and routing of datagrams. IP protocol allows only raw transmission. This layer also supports some other protocols: ARP, RARP, ICMP, IGMP.

Address Resolution Protocol (ARP) 

If physical address of a machine is known then we can find the IP address of that machine by using ARP protocol.

Reverse Address Resolution Protocol (RARP) 

This protocol is just opposite to ARP. If we know the IP address of a machine then we find out the physical address of that machine by the help of RARP protocol.

Internet Control Message Protocol (ICMP)

In case of message delivery fail, ICMP is responsible to send a negative acknowledgement message about packet problems.

Internet Group Message Protocol (IGMP)

This protocol is used for multicasting.

TRANSPORT LAYER

This layer uses two protocols: TCP and UDP. This layer is responsible for process to process delivery.

Transmission Control Protocol (TCP)

This protocol is reliable and connection oriented protocol. It ensures error free communication and is responsible that data packets arrived in sequence.

User Datagram Protocol (UDP)

This protocol is faster because it does not provide reliability.

APPLICATION LAYER

This layer helps to user to run various application on Internet. These are FTP (File Transfer Protocol), Telnet (Remote login), SMTP (email), HTTP (www) etc.

Protocols Used at Different Layers at a Glance in TCP/IP:

Application- SMTP, FTP, DNS, WWW, HTTP, TELNET etc.

Transport- TCP, UDP

Network- IP, ARP, RARP, ICMP, IGMP

Physical- Specific to the underlying physical media at Hardware level.