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CSC 363: Local Area Networks . DePaul University Winter Quarter 1999 LoriLee M. Sadler. Intro to Course. How to contact me Office Hours Course Components Schedule. Small Group Project. 4 Cases from which to choose Final product Group registration on the web. The LAN Lab.
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CSC 363: Local Area Networks DePaul University Winter Quarter 1999 LoriLee M. Sadler
Intro to Course • How to contact me • Office Hours • Course Components • Schedule
Small Group Project • 4 Cases from which to choose • Final product • Group registration on the web
The LAN Lab • Access hours • ID required • What’s up there
Basic Terms • Clients • Peers • Servers
Problem: • You’re installing a small network for a collections agency. There will be only five stations on the network. Cost is an issue, and the company would prefer not to dedicate an individual’s time to maintaining a network. However, the agency is also concerned about keeping its data safe, and the users are not sophisticated users.
Network Types • Server-based • Peer to Peer • Hybrid
Server-Based Networks • Also called client-server networks • Servers • responsible for security and administration • single login required for network resources • network services (e.g., printing, file storage) • Clients • typically less powerful than servers • need client software to access network services
Domains • Unique to server-based networks • =>collections of networks and services that share security trust information • Domain controllers handle security and permissions • PDC=> • BDC=>
Advantages central security & admin Optimized dedicated servers Single-password security Scales to large # of users Disadvantages Dedicated servers are more expensive than plain old computers Expensive NOS and clients Requires dedicated sysadmin Server-based Networks pros & cons
Peer Networks • Also called peer-to-peer networks • No servers--every machine is a client and a server • Users control access and security to each networked resource
Workgroups • Typically grouped by users rather than by services or resources • Password access to individual networked resources • Peer machines not optimized for resource sharing
Advantages Cheap Easy to set up No sysadmin Users control access & “Security” No reliance on other computers Disadvantages All advantages are also disadvantages Inefficient use of peer equipment Intrusive, easy to break security Bad idea for large networks Peer NetworksPros and Cons
Peer Security One user or all users--no user-level security Each shared resource must have its own password Lots of passwords means more points for hacking Server Security Centrally managed security Security controlled by groups of users and appropriate resources Peer Security vs. Server Security
Hybrid Networks • Combines aspects of peer-to-peer and server networks • All the advantages of server-based networks and most of peer-to-peer • Some of the disadvantages of server-based networks
Would a Server-based Network be good for the Collections Agency?
Server types • File Servers • Print Servers • Application Servers • Message Servers • Database Servers
Server Software • Called Network Operating System (NOS) • Windows NT • Novell Netware • Requires matching clients
Server Hardware • Typically more powerful than a client • NT requires a minimum of: • Pentium processor • 16MB of RAM • Reality Check • Pentium II • 64-256MB RAM • Large hard drive
Client Hardware • 486 or better • 4MB of RAM or better
Problem: You are considering networking topologies for a network for a telemarketing firm. • When would a ring network be appropriate? • When would a star network be appropriate? • When would a bus network be appropriate?
Network Topologies • Bus • Ring • Star • Mesh
Problem: You are designing a network for an office complex. Several buildings must be linked together with high-performance long-distance links, and servers within the building must be linked together with a high-speed backbone. Hundreds of clients computers in each building must be inked together inexpensively. What media will you use?
Network Media • Copper • Glass • Air • Radio
Network protocols: • Hardware protocols • Hardware-software protocols • Software protocols