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Computer Networks. Network Protocols. Networking Protocols. A protocol defines the rules of procedures, which computers must obey when communicating with each other. The OSI Reference Model is an abstract description for layered communications and computer network protocol design.
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Computer Networks Network Protocols
Networking Protocols • A protocol defines the rules of procedures, which computers must obey when communicating with each other
The OSI Reference Model is an abstract description for layered communications and computer network protocol design.
OSI Model • OSI – Open Systems Interconnect • The OSI model is a standard used to allow different vendors to interoperate . • The OSI model is known as a layered protocol, specifying seven (7) layers of interface. Each layer performs a well defined function.
Layers of the OSI Model All People Seem To Need Data Processing
Layer 1: Physical • The physical layer defines how a transmission medium such as a cable connects to a computer. • This layer also specifies how to physically move data (raw bits) between modems.
Layer 2: Data Link • Divides the stream of bits received from the network layer into manageable data units called frames. • Responsible for error-free transfer of frames to other computer via the Physical Layer.
Layer 3: Network • The network layer identifies computers on a network and determines how to direct information transferring over a network. • Responsible for addressing and routing.
Layer 4: Transport • The transport layer corrects errors in transmission and ensures that information is delivered reliably. • It manages the flow control of data between parties across the network. • It ensures that the whole message arrives intact and in order.
Layer 5: Session • Responsible for dialogue control
Layer 6: Presentation • This layer is concerned with ensuring that a receiving computer understands the information sent to it. • It converts information from one form to another • Involves data encryption, compression and translation services.
Layer 7: Application • This layer facilitates user functions and provides guidelines for network services. • Functions include file, print, message, database, and application services.
Benefits of The OSI Model • Dividing the complex network operation into more manageable layers. • Networks can be updated more easily by replacing individual layers instead of the entire system software. STOP HERE FOR TODAY…
HTTP • HyperTextTransfer Protocol • The underlying protocol used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands.
HTTP • For example, when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page. http://www.webopedia.com • Click here to read another explanation: http://encyclopedia2.thefreedictionary.com/Http+protocol
FTP • File Transfer Protocol • The protocol for exchanging files over the Internet. • FTP is most commonly used to download a file from a server using the Internet or to upload a file to a server (e.g., uploading a Web page file to a server). http://www.webopedia.com
IEEE protocols • Click here to see what the IEEE is http://whatis.techtarget.com/definition/0,,sid9_gci214016,00.html
IEEE802.16g • IEEE 802.16 is a series of Wireless Broadband standards authored by the IEEE. • IEEE 802.16 is written by a working group established by IEEE Standards Board in 1999 to develop standards for the global deployment of broadband Wireless Metropolitan Area Networks. • The current version is IEEE 802.16-2009 amended by IEEE 802.16j-2009. 16g was authored in 2007 for Management Plane Procedures and Services
HTTPS • HyperTextTransfer Protocol Secure • Used to access a secure Web server. When https:// is used as the prefix of a Web address rather than the common http://, the session is managed by a security protocol, and the transmission is encrypted to and from the Web server. http://www.techweb.com/encyclopedia
TCP • TCP is Responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.
IP • IP is responsible for moving packets of data from node to node. IP forwards each packet based on a four byte destination address(the IP number).
TCP/IP • Transmission Control Protocol/Internet Protocol • The suite of communication protocols used to connect hosts on the internet. • TCP/IP uses several protocols, the two main ones being TCP and IP. http://www.webopedia.com
IEEE802.11a/b • Institute of Electrical and Electronics Engineers
VoIP • Voice over Internet Protocol • A category of hardware and software that enables people to use the Internet as the transmission medium for telephone calls by sending voice data in packets using IP. http://www.webopedia.com