CHAPTER Introduction to LANs

MODULE Purpose and Use of a Network

Definition of a Network Composed of computing and information devices connected together –clients –servers –shared printers –other shared devices –internetworking devices link to the external world –Etc.

Purpose Access and share local resources and information –Hard and soft resources Access and share global resources and information –Internet resources Messaging, Collaboration etc.

A Note on Sharing and Collaboration Sharing –One shares the application –The other watches the changes being made Collaboration –Both share the applications and both can make the changes

Network Types Locally oriented (LAN) Globally oriented (WAN) A combination of the above two types

A Simple Network Client Server Peripheral Device (Modem) Printer Directly attached peripheral (Network Printer)

Appliances Network appliance –Network Attached Storage (NAS) –Network Printer Internet appliance

NAS NAS can be directly attached to network (switch, for example) NAS components –Processor –Embedded OS (Eg: Embedded Linux) –Embedded software (Eg: SAMBA Server)

Sample Components of a Simple Network Network Hardware Network Software Resources –Hard resources –Soft resources Personnel –Administrators –Users

Hardware Servers Clients Peripheral devices –Network printers –NAS Media (Cabling) –Twisted pair, coaxial cable, optical fiber etc. –Wireless networks without cables Networking Devices –Hubs, switches, routers

Media CAT 5 –100 Mbps LANs CAT 5e –1000 Mbps LANs CAT 6

Internetworking Devices Hub –Simply shares the electrical connection Switch –Switches the data packet based on MAC address Bridge Router –Routes the data packet based on the IP address

Software Network operating system –Windows 2003 Server, Windows Server 2000, Linux etc. Client operating system –Windows XP, Windows 2000, Linux etc. Various application server operating systems –SQL server, Web server, FTP server etc.

Resources Hard resources –Printers, scanners etc. Soft resources –Folder, application etc.

Hard Resource Sharing Example Printer (Attached directly or to the Server) Print Jobs Print Server Print Queue

Soft Resource Sharing (File Server) Example Server Client Tariff Resource (Folder to be shared). User Administrator

Application Server Example Server with SQL engine and database. Client Sharing of SQL engine based application. User Database Administrator

Messaging Example Remote Client Messaging Server Client User Administrator Internet Internet Gateway

Personnel –Administrators Administrator, account operator, server backup operators etc. –Users Local user, power user, global user etc.

Network Administrator's Responsibilities Install, manage and fine-tune the network resources Create and manage users Assign privileges to users to use the resources –Sharing resources –Accessing network applications Ensure LAN security

Users Global users Local users Group of users Power users Users with administrative privileges

Earlier Windows Servers Windows NT –Windows NT Workstation, Windows NT Server, Windows NT Enterprise Server Windows 2000 –Windows 2000 Professional –Windows 2000 Server –Windows 2000 Advanced Server –Windows 2000 Data Center Server

Windows 2003 Server Versions Web Edition Standard Edition Enterprise Edition Datacenter Edition

Network (Services) Servers DHCP (Services) Server DNS (Services) Server Proxy (Services) Sever WINs (Services) server RAS (Services) Server –Routing and Remote Access Server VPN (Services) Server Share Point services

Application Servers SQL Server Web (Service) Server Media (Service) Server

Major Network Architectures.Net J2EE

Web Research Areas Directly attached network peripherals –Network printer, Network stand-alone hard drives (Snap) –Network appliance and a web appliance Variations of the Windows Server 2003 operating system What is the.Net architecture ?

Key Words Hard and soft resources Client operating systems –Windows 9x, Windows NT, Windows 2000 Professional, Windows XP, Linux, OS/2, Mac OS X Server operating systems –Windows NT Server, Windows 2000 Server, Windows 2003, Novell NetWare, Unix, Linux, OS/2 Warp

Further Keywords Sharing of printers –local printer –shared printer –network printer Symmetric Multi Processing (SMP) Clustering –Load balancing

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