Explain TCP/ IP Reference Model in detail

TCP/IP Protocol Suite:

Ø  Model around which internet is developed.

Ø  Has four architecture layers

Ø  Protocol-dependant standard

Ø  Theoretical we learn OSI but when it comes to practical implementation, we use TCP/IP protocol suite.

Ø   TCP/IP is a hierarchical protocol. The term hierarchical means that each upper-level protocol is supported by one or more lower-level protocols.

Physical and Data Link Layers

Ø  At the physical and data link layers, TCP/IP does not define any specific protocol. A network in a TCP/IP internetwork can be a local-area network or a wide-area network.

Network Layer

Ø  At the network layer ,TCP/IP supports IP which uses four supporting protocols: ARP, RARP, ICMP, and IGMP.

Internetworking Protocol (IP)

Ø  IP is an unreliable and connectionless protocol which does not  provide error checking or tracking. IP transports data in packets called datagrams

Address Resolution Protocol

Ø  ARP is used to find the physical address of the node when its Internet address is known.

Reverse Address Resolution Protocol

Ø  RARP allows a host to discover its Internet address when it knows only its physical address. It is used when a computer is connected to a network for the first time or when a diskless computer is booted.

Internet Control Message Protocol

Ø  ICMP is a mechanism used by hosts and gateways to send notification of datagram problems back to the sender. ICMP sends query and error reporting messages.

Internet Group Message Protocol

Ø  IGMP is used to facilitate the simultaneous transmission of a message to a group of recipients.

Transport Layer

Ø  Traditionally the transport layer was represented in TCP/IP by two protocols: TCP and

UDP.

TCP	UDP
·     Transmission Control Protocol ·     Connection-oriented ·     Reliable Communication(With ACK’s) ·     Slower data transportation ·     Protocol No. is 6 ·     Ex: HTTP, FTP, SMTP etc	·     User Datagram Protocol ·     Connection less ·     Unreliable Communication(No ACK’s) ·     Faster data transportation ·     Protocol No. is 17 ·     Ex: DNS,DHCP,TFTP etc

Stream Control Transmission Protocol

Ø  The Stream Control Transmission Protocol (SCTP) provides support for newer applications such as voice over the Internet. It is a transport layer protocol that combines the best features of UDP and TCP.

Application Layer

Ø  The application layer in TCPIIP is equivalent to the combined session, presentation, and application layers in the OSI model.

Ø  It initiates the process, defines the format and create & terminate the session.

Ø  Many protocols are defined at this layer.

Application Layer Protocols inside TCP/IP

Ø  Application layer provide an interface between software running on a computer and network itself.

Ø  Examples for this layer are: Telnet, FTP, SMTP, SNMP, DNS, DHCP etc

HTTP

Ø  Allow to access Webpage

Ø  https://onlinesmarttrainer.blogspot.com

FTP (File Transfer Protocol)

Ø  It allows you to transfer files from one machine to another

Ø  It also allows access to both directories and files

Ø  It uses TCP for data transfer and hence slow but reliable

 Telnet

Ø  Telnet is used for Terminal Emulation

Ø  It allows a user sitting on a remote machine to access the resource of another machine

SMTP

Ø  Allow you to send and receive emails messages

TFTP (Trivial File Transfer Protocol)

Ø  This is stripped down version of FTP

Ø  It has no directory browsing abilities

Ø  It can only send and receive files

Ø  It uses UDP for data transfer and hence faster but not reliable

Simple Network Management Protocol

Ø  SNMP enable a central management of network

Ø  Using SNMP an administrator can watch the entire network

Ø  SNMP works with TCP/IP

Ø  It uses UDP for transportation of the data

DNS (Domain Name Service)

Ø  DNS resolve FQDN with IP address

Ø  DNS allows you to use a domain name to specify and IP address

Ø  It maintains a database for IP address and Hostnames

DHCP (Dynamic Host Configuration Protocol)

Ø  Dynamically assigns IP address to hosts

Ø  Also provide DNs and Gateway information if needed