Layer 7 (Application) – Communicate directly and performs common services for the application.
HTTP – WWW was based off this protocol. Hypertext Transfer Protocol also allows the transferring data on the internet.
IMAP – Internet Message Access Protocol a commonly used protocol for retrieving emails off a server. V4 is the current version of this protocol.
POP3 – Similar to the IMAP protocol retrieves the e-mail of a server. When deleting a message the IMAP will completely gets rid of the message, on the other hand POP3 will simply disconnect from the server.
STMP – Simple Mail Transfer Protocols is currently the most used protocol. It can send and receive e-mail over the internet. It is commonly known as a SMTP.
ADSL
ADSL which stands for Asymmetric Digital Subscribers Line is a high speed transmission protocol. It works at the physical layer. ADSL uses cooper telephone line rather than the old conventional voiceband modem. It is a full-duplex system. Broadband is an example ADSL transmission. It uses the frequencies which are not used by the voice telephone line. A micro filter allows for this to happen. It allows the ADSL connections as well as the voice calls working simultaneously on the same line. It can be used for short distance communication of around 4 Km. The phone lines differ in the quality because they are originally made with DSL technology. This protocol is very important because it uses the DSL technology which implements an ATM layer over the low level bitsream layer. This lets a variety of technology to work over the same link. It works at the physical layer.
RS 232
Recommended Standard 232 (RS 232) applies to serial data transfer such as the 9 pin serial connecter which are commonly used on a computer motherboard. The data is sent in as time series of bits. Synchronous & Asynchronous is both supported by this standard. This standard and states the number of control circuits that can be or need to be used to connect the DCE & DTE terminal with one another. Data and control circuits which are signalled from a DTE connected to a DCE or vice versa will always flow and operate in one direction this is called half duplex. Only full duplex allows data to be sent and received in both directions at the same time.
IEEE 802
Institute of Electrical and Electronics Engineers 802 is the standard which looks after LAN and metropolitan area networks. It is restricted to networks which are carrying variable-size packets. It works with to lower layer of the OSI model. The data link layer and the physical layer. It further splits the data link layer into Logical Link Control and Media Access Control.
IEEE 802.11
This is the standard which handles Wi-Fi connections. This the current way of deploying portable broadband internet to devices. You would normally find Wi-Fi connections in hotels, cafes & airports. People have started to use it at home aswell. Nearly all personal computer operating systems, game consoles, laptops, smart phones, printer and other peripherals support Wi-Fi.
IEEE 802.16
It is known as the Broadband Wireless Access. This is the standard for the upcoming WiMax system. It stands for Worldwide Interoperability for Microwave Access. It is a telecommunication technology which uses wireless transmission to deploy broadband to anywhere. It uses 75 Mbps broadband speed without the need for cables.
PPP
PPP which is Point to Point Protocol which enable and establishes a direct connection between two device over a serial cable, including phone lines and fibre optic links. There are two sub categories of PPP. PPP over Ethernet and PPP over ATM, both used for similar things using DSL internet service. PPP works at the data link layer protocol; it is another important protocol because it acts as a connection for synchronous and asynchronous circuit which have stopped using non-older standard Serial Line Internet protocol.
Ethernet
Widely used for LAN technology. It uses coaxial cable and is also used in wireless LAN’s. The newer used Ethernet systems are called the 10 BASE T. They reach up to transmission speeds of 10Mbps. It works in the data link layer. It is quite important because everywhere you go you would mostly see the Ethernet system’s deployed.
Internet Protocol (IP)
Internet Protocol (IP) is the protocol which allows communication across packet switched internetwork using TCP/IP. IP is and really important protocol because it delivers the packets from the source host to the destination node based on its address. It also defines the addressing methods and structuring for datagram encapsulation. IPv4 is the main dominant protocol for the internet although the IPv6 is more widely known and deployed. This works at the network layer. It contains packetization which is data from the upper layer control encapsulated inside another packet or more packets or more datagram’s. A control setup circuit is not required in order for a host to send packets to a host which it has not previously communicated with.
IPv4
IPv4 is the data oriented protocol used on a packet switched internetwork such as Ethernet. It does not guarantee the delivery but avoids duplicate deliveries. IPv4 using packet checksums provides data integrity protection. It works at the data link layer. It is an important protocol because together working with IPv6 at the core of standards based internetworking ways of the Internet. IPv4 is also vastly deployed Internet layer protocol.
IGP
It stands for Interior Gateway Protocol. It used within an autonomous system (AS). IGP is divided into two groups Distance-Vector Routing Protocol and Link-State Routing Protocol. It is used in contrast with EGP with is the opposite Exterior Gateway Protocol is used to determine network reachability between AS and it uses IGP to resolve routes within the AS.
RIP
Routing Information Protocol (RIP) is the protocol used in LAN networks. It works at the Application Layer. It is classified as an IGP. It uses distance-vector routing algorithm. It is also an important protocol because it runs parallel with transport layer. It is used by routing applications to swap routing table information with nodes. RIP is also used at the Network Layer because it has the ability to support a network.
OSPF
Open Shortest Path First (OPSE) is a link state routing protocol which also is categorized as IGP which works at the data link layer. It uses link-state routing algorithm. OSPF is most widely used IGP in large networks. OSPF is an important protocol because it is completely based off destination IP addresses found in IP packets. It is designed to support variable-length subnet masking. If OSPF detects changes in a topology such as link failures then it immediately converges on a loop free routing structure.
TCP
Transmission Control Protocol is middle level communication protocol which allows communication between application programs and internet protocols. TCP is vastly deployed and used by many internet popular services application protocols including the WWW and the e-mail. TCP works at the TCP layer. As motioned before it is important because it allows communication at the middle level between application programs and internet protocols. This happens when an application program wants to transmit a large chunk of data across the Internet using IP instead of breaking the data into IP-sized pieces and issuing a series of IP requests. Software can give a single request to TCP and the TCP will handle the IP details.
DHCP
Dynamic Host Configuration Protocol is used to get the parameters obligatory for functions in an internet protocol network. New device can be added to the network without the need for a lot of configuration because the work load for the system administrator is reduced by this protocol. DHCP is a really important protocol because it automatically retrieval of default gateway’s, IP addresses, subnet masks and other required IP parameters. When a client configured by DHCP connects to the network it automatically sends a broadcast query asking for the required information to the DHCP server. The IP address and information about the client configuration such as the gateway, domain name & etc, is all managed by the DHCP server.
FTP
File Transfer Protocol is used to transfer data from one computer to another via a network similar to the internet. FTP is quite an insecure way of transferring data because there is not straightforward way of transferring data which is encrypted. It works at the application layer. When the FTP protocol is in active mode the FTP client will release a dynamic port which will send the FTP server the dynamic port number which is used to listen over the control stream and waits for the connection from the FTP server.
File Transfer
File transfer is a method of transmitting files over a computer network and the Internet. There are many methods and protocols which allow transmission of files over networks. Computers and servers which are setup are file transfer service are called file servers. There are two main types of file transfer services. The Push bashed file transfer and the Pull based file transfer. In the Push based transfer the receiver initiates a file transmission request and the push based transfer the send the sender initiates a file transmission request. File transfer works at the application layer protocol. It is an important protocol because it is a convention which defines how file transfer happens between two points.
HTTP
HTTP stands for Hyper Text Transfer Protocol. HTTP client initiates and send requests and start a transmission control protocol (TCP) connection to a unique port on a host. The HTTP listening server will wait till it receives the request message. When it receives the message then it will send back a status or a replay saying HTTP/2.1 300 OK and it will also send its own message with the status reply.
DNS
DNS which stands for Domain Name System is a naming system for computers, services, or any other resource in the Internet. It will translate the human text to binary indentifies associated; this allows network equipment to locate and addresses these devices world-wide. Often the concept of a phonebook is applied to make someone understand the theory of DNS, It acts as a phonebook for the Internet by translating the human text to IP addresses. For example www.google.co.uk is translated to 74.125.76.104.
SMTP
SMTP protocol which stands for Simple Mail Transfer Protocol. SMTP is an internet standard for electronic mail transfer across IP addresses. This is also a text based protocol. In text based one or more recipients can be added and other encoded subjects can also be attached and transfer. When the mail is transferred it will first go to a remote server using different commands of quires and responses between the server itself and the client.
MIME
Multi Purpose Internet Mail Extensions (MIME) is a Internet Standard which extends the format of an e-mail to support character sets other than the US-ASCII, non-text attachments, message bodies with multiple parts header information in non ASCII character sets. It works at the presentation layer and it is important for e-mail because it defines mechanisms which allow other kinds of information to be sent via the e-mail. This include text language other than English using character encoding other than ASCII and 8 bit binary content and files containing sound, video, images and computer programs.
