Lecture Networking essentials plus (3 e) Chapter 5 Introducing network standards

Lecture Networking essentials plus (3 e) Chapter 5 Introducing network standards. The main contents of the chapter consist of the following Open systems interconnection (OSI) model, IEEE 802.x standard, device drivers and OSI.

Open Systems Interconnection (OSI) Model

 Network Communications

 OSI Model

 Windows NT and the OSI Model

Network Communications 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

OSI Layer Relationships

Application Layer (7)

 Topmost layer

 Represents services that directly support user

applications

 Window to network services

 Handles network access, flow control, and error

recovery

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, encryptionI/O redirectors work to redirect resources to a server

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

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

 Performs packet switching, routing, traffic

management, and controls congestion of data

Simple Data Frame

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”

OSI Model Layer Mnemonics

Presentation People Pizza

Packet Assembly and

Disassembly Process

Windows NT and OSI

Software and Protocols

Windows NT Architecture

with Boundary Interfaces

The IEEE 802.x Standard

 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

802 Specification Categories

802.1 Internetworking

802.2 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 LAN

802.5 MAC layer, Token Ring LAN

802.6 Metropolitan area Network (MAN)

802.7 Broadband Technical Advisory Group

802.8 Fiber-Optic Technical Advisory Group

802.9 Integrated Voice/Data Networks

802.10 Network Security

802.11 Wireless Network

802.12 Demand Priority Access LAN, 100BaseVG-AnyLAN

802.13 Unused

Project 802 LLC and

MAC Sublayers

Project 802 LLC and

MAC Standards

Device Drivers and OSI

 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:

Communication Between the NIC and Network Software

Network Driver Interface

Specification (NDIS)

Three types of network software:

frames that are sent to and received from network

and moves frames between protocol stack and interface hardware