Introducing Network Standards Open Systems Interconnection (OSI) Model IEEE 802.x Standard Device Drivers and OSI 1.

Introducing Network Standards Open Systems Interconnection (OSI) Model IEEE 802.x Standard Device Drivers and OSI

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Open Systems Interconnection (OSI) Model

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Network Communications OSI Model Windows NT and the OSI Model

Network Communications

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Sending Computer Must: Recognize data Divide it into manageable chunks Add information to determine its location

and identify the receiver

Add timing and error-checking information Put data on the network and send it

Seven-Layer OSI Model

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OSI Layer Relationships

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Application Layer (7) Topmost layer Represents services that directly support user

applications Window to network services Handles network access, flow control, and

error recovery

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Presentation Layer (6) Network translator On sending end, determines formatting used to

exchange data among computers and adds formatting so data can be understood by network

On receiving end, translates data from application format to a common intermediate format

Manages data compression, translation, encryption I/O redirectors work to redirect resources to a server

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Session Layer (5) Allows two applications on different computers

to open, use, and close connections Performs name recognition and provides

security Provides synchronization by placing

checkpoints in the data stream Implements dialog control between

communication processes

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Transport Layer (4) Sending end: repackages message, divides

long messages to ship properly over determined route and arrive error-free

Receiving end: unpacks message, reassembles it, and acknowledges receipt

Provides flow control, error handling, and solves transmission problems

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Network Layer (3) Addresses the package using network address

scheme Determines the best route on the network

based on network conditions, priority of service

Performs packet switching, routing, traffic management, and controls congestion of data

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Data-Link Layer (2) Sending end: sends data frames from network

layer to physical layer Receiving end: packages raw bits from

physical layer into data frames Parts of data frame: Destination ID, Sender ID,

Control Data Acknowledges data frames, error checking,

and verification

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Simple Data Frame

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Physical Layer (1) Bottommost Layer Hardware-oriented, establishes and maintains

physical link between communication computers

Defines how the cable is attached to the NIC Packet sent as an unstructured raw bit stream

over physical medium Referred to as the “hardware layer”

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OSI Model Layer Mnemonics

Application All Away

Presentation People Pizza

Session Seem Sausage

Transport To Throw

Network Need Not

Data-Link Data Do

Physical Processing Please

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OSI Layer Down Up

Packet Assembly and Disassembly Process

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Windows NT and OSI

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Software and Protocols

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Windows NT Architecture with Boundary Interfaces

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The IEEE 802.x Standard

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The 802 Project Model

802 Specifications

Set Standards for: Network Interface Cards (NICs) Wide area network (WAN) components Components used to create twisted-pair and

coaxial cable networks

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802 Specification Categories

802.1 Internetworking802.2 Logical Link Control (LLC)802.3 MAC layer, Carrier Sense Multiple Access with Collision

Detection (CSMA/CD) LAN (Ethernet)802.4 MAC layer, Token Bus LAN802.5 MAC layer, Token Ring LAN

802.6 Metropolitan area Network (MAN)802.7 Broadband Technical Advisory Group802.8 Fiber-Optic Technical Advisory Group802.9 Integrated Voice/Data Networks802.10 Network Security802.11 Wireless Network802.12 Demand Priority Access LAN, 100BaseVG-AnyLAN802.13 Unused802.14 Cable modem standards802.15 Wireless personal area networks (WPAN)802.16 Broadband wireless standards

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Project 802 LLC and MAC Sublayers

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Project 802 LLC and MAC Standards

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Device Drivers and OSI

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Role of Drivers Network Environment Network Driver Interface Specifications (NDIS) Open Data-Link Interface (ODI) Bridging NDIS and ODI

Role of Drivers

Drivers for nearly every type of device including: Input devices, such as mouse and keyboard devices SCSI and IDE disk controllers Hard and floppy-disk drives Multimedia devices such as microphones, cameras, and recorders Network Interface Cards (NICs) Printers, plotters, tape drives, and so forth

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Communication Between the NIC and Network Software

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Network Driver Interface Specification (NDIS)

Three types of network software: Protocol Stack: Provides network communications; generates and

disassembles frames that are sent to and received from network

Adapter Driver: Controls network interface hardware; works in MAC sublayer and moves frames between protocol stack and interface hardware

Protocol Manager: Controls activity between protocol stack and MAC

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