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Chabot College. ELEC 99.05 Ch 2 - OSI Model. What is Networking?. Networking - the interconnection of workstations, peripherals, terminals and other devices. Network Protocols. In today’s networks, it is possible for different types of computers to communicate.
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Chabot College ELEC 99.05 Ch 2 - OSI Model
What is Networking? Networking - the interconnection of workstations, peripherals, terminals and other devices.
Network Protocols In today’s networks, it is possible for different types of computers to communicate. Macs, PCs, and mainframes can all share devices, data, and information, as long as they all speak the same language, orprotocol.
Network Protocols Protocol - a set of rules, or an agreement, that determines the format and transmission of data.
The Internet Protocol All devices on the Internet “speak” the same protocol: theInternet Protocol, orIP. The Internet actually uses a group, or suite, of protocols calledTCP/IP which includes HTTP.
Networking Growing Pains Emerging network technologies were built using different kinds of hardware and software. Many of the new network technologies were incompatible.
Toward Standardization To address the problem, the International Organization for Standardization (ISO) researched leading networks schemes: • Digital’s DECnet • IBM’s SNA • DoD’s TCP/IP (non-proprietary)
The ISO’s Standard The ISO recognized there was a need to create a network model that would help vendors create networks that would work compatibly and interoperably with other networks. In 1984, the ISO released their networking model.
ISO’s OSI Reference Model A Layered Model: A mnemonic: All People Seem To Need Data Processing
ISO’s OSI Reference Model A Layered Model: Another mnemonic: APresent Session Transports Network Data Physically
ISO’s OSI Reference Model Open System Interconnection (OSI)
Data Link Sublayers LLC (Logical Link Control) MAC (Media Access Control) IEEE 802 Extension to the OSI Model
Moving Data End System End System
Data Encapsulation Example End System Intermediate Systems