1. IT Service Delivery And Support Week Three - OS
IT Auditing and Cyber Security
Spring 2014
Instructor: Liang Yao (MBA MS CIA CISA CISSP)

2. Servers Based Network File Server
The file server is the repository of user data files. Some companies store application programs on the file server instead of allowing employees to store these programs on their individual drives.
The file sever is controlled by a network operating system. The network operating systems controls access to each of the directories and files on the sever.

3. Print Server
A print server allows two or more users to share the use of one or more printers controlled by the print server. The servers can be attached directly to the print server, or they can be equipped with a network interface card and be controlled through the LAN connection.
Often the file sever program and print server program run on the same computer.

4. Communication Server
The communication server provides shared access to modems and facsimile modems. These modems are used for outbound and inbound communication. The three most common remote access communication server programs are Remote Access Server (RAS), Remote Authentication Dial User Service (RADIUS), and Terminal Access Controlled Access System (TACACS).
IT Audit Fundamentals
4/28/2019

5. emulators
There is also a class of communication servers called emulators. Some computer vendors design their computers to only work with a terminal that is designed for that specific computer.
e.g. IBM 3270 for Mainframe and IBM 5250 for IBM AS/400.

6. E-Mail and GroupWare Servers
The sever
The server runs the electronic mail system. – Lotus Notes, Microsoft Exchange Server and sendmail (UNIX).
Database Server
A database server runs a DBMS such as DB2, Oracle, Sybase, or SQL Server.
Security Server
The Security server provides common control for access to the network, and access to applications running on the network. The security server does not control access to files on various servers. That is the responsibility of the server maintaining those files.
Application Server
An application server is a server running programs other then those mentioned above.

7. Common Network OS IBM OS/2 IBM OS/390 LINUX Novell Netware MAC OS X
Microsoft windows 2000/NT
UNIX

8. Advantage of Distributed Environment
Advantages:
Leverage desktop computing
Enable some systems to be delivered sooner than traditional mainframe systems
Uses graphic user interface
Free up expensive mainframe computing cycle – might delay or lengthen mainframe upgrade cycle.

9. Disadvantages of Distributed Environment
May create bottlenecks in network
Applications take longer to deliver because they are more complex
Uses command line and text base interface
Additional cost of desk top and tier-two servers are not accounted for in the long-term budget
Decentralized control
Security in the client/server environment might not be a strong as mainframe security