TCP/IP Model

TCP/IP Model 

This model has been developed in 1970s by department of Defense of America, so, it is also known as DoD Model.

It has been developed to make protocols platform independent.

It defines protocols as an open standard.

It has 4 layers

Application Layer

Some Protocols:-

· NetBIOS (Network Basic Input Output System)

o It is used for communication devices in a same work group network.

o It helps to resolve computer’s flat name to its respective IP and vice-versa.

o By default this service is active at a computer.

· DNS (Domain Name System)

o It is used in a domain network .i.e. based on hierarchical naming structure.

o It resolve hierarchical name to its respective IP and vice-versa.

o It can support a very large network.

· DHCP (Dynamic Host Configuration Protocol)

o This protocol provides a service by which IP address, subnet mask, default gateway, DHCP server address, DNS server address, lease duration and restriction can be provided to DHCP client computers.

o A computer at which DHCP is configured is known as DHCP server.

o At DHCP server a scope with above information is configured.

o DHCP server provides above information dynamically means as per client request.

o In case, DHCP client is unable to find DHCP server, it automatically generate an IP address that belongs to 169.254.X.Y series known as APIPA (Automatic Private IP Address)

o To release IP address

ipconfig\release

o To get new IP address

ipconfig\renew

· BootP (Boot Protocol)

o It is an older version of DHCP.

o It is used to provide IP address and subnet mask with Bootstrap loader at terminal.

· TelNet (Telecommunication Network)

o It is used to configure a node remotely through command line.

o It is supported by TCP.

o TelNet service must be enable with a user account (with password).

· WINS (Windows Internet Network Service)

o It is an older version of DNS.

o It is used to resolve computer name to IP address & vice-versa, but it can support flat name and small network.

· FTP (File Transfer protocol)

o It is used to download and upload data at a central location .i.e. known as FTP server.

o FTP works at port 20 for download and port 21 for uploading.

o It provides security with username and password.

· HTTP(s) (Hyper Text Transfer Protocol (secure))

o It is used to open a web page through a browser.

o It works at port 80.

o To provide security at a web page secure socket layer (SSL) service is attached with HTTP, then HTTP become HTTPs.

· NNTP (Network News Transfer Protocol)

o It is used to create a news group in an organization by which news can be flashed in the network.

o It works at port 119.

· SMTP (Simple Mail Transfer Protocol)

Transport Layer

· TCP (Transmission Control Protocol)
o It supports reliable data transmission because it works with acknowledgement.

· UDP (User Datagram protocol)

o It supports unreliable data transmission because it does not support acknowledgement.

Network Layer

· IP (Internet Protocol)

o It is used to provide logical identification to a network device.

o This logical identification is provided with a sequence of number.

o It is available into 2 versions

IPv4
IPv6

· ICMP (Internet Control Message Protocol)

o It is used to check connectivity between 2 nodes by sending and receiving message packets.

· ARP (Address Resolution Protocol)

o It is used to generate an ARP table which contains IP address with its respective MAC address.

· RARP (Reverse Address Resolution Protocol)

o It resolves MAC address to its respective IP address with the help of ARP table.