ISOOSI Reference Model ISOOSI Reference Model AJCE Principal

ISO/OSI Reference Model

ISO/OSI Reference Model AJCE Principal Marian Principal

ISO/OSI Reference Model AJCE Principal H 1 PA Marian Principal

ISO/OSI Reference Model AJCE H H 1 2 Marian Principal PA PA Front Off

ISO/OSI Reference Model AJCE Principal PA PA Front Off Dispatch H H H 1 2 3 Marian

ISO/OSI Reference Model AJCE Marian Principal PA PA Front Off Dispatch H H H 1 2 3

ISO/OSI Reference Model AJCE Marian Principal PA PA Front Off Dispatch H H 1 2 H 3

ISO/OSI Reference Model AJCE Principal Marian Principal H 1 PA PA Front Off H 2 Dispatch H 3

ISO/OSI Reference Model AJCE Principal Marian Principal PA PA H 1 Front Off H 2 Dispatch H 3

ISO/OSI Reference Model • • Open System Interconnect model Created by ISO (International Organization for Standardization) 1970’s It is used to communicate n/w devices of diff vendors It Contains 7 layers

ISO/OSI Reference Model

ISO/OSI Reference Model

ISO/OSI Reference Model • • • From top Application, Presentation , Session � upper layer or Software layer Transport layer � Heart of OSI Network, Data Link, Physical � lower layer or H/W layer APSTNDP All People Seems To Need Data Processing

ISO/OSI Reference Model Working of Appication layers • • • communicated with other application layer (only other application layer understand) All application begins with this layer Provide n/w services to application process identify the communication partner (ex if want to sent email then check to connect with email server otherwise will not work) provide user authentication Determine all n/w resources

Working of Appication layers, Protocol Used • • • • SMTP (Simple mail transfer Protocol) for mail POP 3 (Post office protocol) to locate email server DNS (Domain Name service) in order to convert site name to IP address DHCP (Dynamic Host Configuration Protocol) in a company each host do not have separate IP address in one computer run DHCP server, this DHCP server set IP address to all other computers FTP (File transfer protocol) transferring of files HTTP (Hypertext transfer Protocol) for web SNMP (Simple N/W management protocol)

Working of Presentation layers • • Ensure that data is readable by receiving system Eg now using ASCII format Bt in 1980 IBM are using EBCDIC format (extended binary coded decimal interchange code) • • In N/w always using ASCII format this conversion done by this layer And present the data to N/W so called presentation layer Data conversions such as encoding – decoding Encrypting – decrypting (for security) Compressing –decompressing Format – GIF, JEPG, PNG, ASCII…

Working of Session layers • • • Responsible for establishing, manages, terminating session bt application ie create connection (first create connection to communicate, & destroy at end phone call) it keeps each application in diff sessions Establish Connection bwt client and server RPC (Remote procedure call) SCP (Session control protocol)

Working of Transport layers • • • Error detection and recovery divide the data into packets When sending each packet contains sequence no, so at receiving sys collect all Packet and joined together to get all data If any of the packet missing, ask to resent that packet Data transport reliability ensure is it reached Establish connection btw computer to ensure what speed, how to send and how much data, 2 computer came an agreement for this information flow control if sending data is very fast and receiving host is slow it control Is it is reliable or unreliable communication decided this layer TCP used for reliable, it is connection oriented (eg telephone) guarantee, acknowledge, slower eg exe file UDP not reliable, (eg letter) no guarantee no acknowledge, connection less fast video or audio streaming Here Data are considering as segments

Working of Network layers • • Responsible for routing packets from one node to another Converts the data into packets and ensures that the packets are delivered to their final destination The individual packets are routed to their final destination by connecting devices IP

Working of Network layers

Working of Data Link layers • • Ensure the message are deliver to the proper deceives on LAN the message called frames It governs how to format a frame for use on diff media (diff devices uses diff protocols) data link div into 2 layers LLC (Logical Link Control) WAN protocol MAC(Medium access control) physical address Device Switches

Working of Physical layers • • • responsible for electrical, mechanical or procedural checker (check signals) data convert to bits 1 and 0 Carry bits from one end to another end using any media Only the recipient receives the data Control the synchronization of sender and receiver devices hub, repeaters, cables, modems

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model

Working of ISO/OSI Reference Model