Handout 4 - Clients and Servers

The Purpose and Roles of Clients and Servers

As we have discussed previously a client is a computer that allows a user or users to log on to the network and take advantage of the resources available on the network, whereas a server is a much more powerful computer that administers the network and its resources (Habraken, page 15). From this we can deduce that the role of the server is resource administration and management, whereas the role of the client is resource utilisation.

Hardware  Requirements of Clients and Servers

Since  the roles of clients and servers are radically different, the hardware  requirements of clients and servers are different. Because servers manage and  administer the network and its resources their hardware requirements are much  more advanced than those of clients.

Hardware  Specifications for Clients

Client  workstations vary from the low end to the high end, depending on their purpose.  Here is the specification that you might expect to find on a client:

• » One Intel Celeron, Intel Core 2 Do, or AMD Athlon processor.
• » 2 GB to 4 GB RAM.
• » One to three 320 to 500 GB hard drives.
• » CD/DVD R/W for backups.

Hardware  Specifications for Servers

Servers  vary, like client workstations, from the low end to the high end, depending on  their purpose. Here is the specification that you might expect to find on a  server:

• » One or two Intel Xenon processors.
• » Upwards of 4 GB RAM.
• » Several high speed hard drives with capacities of more than 100 GB each - SCSI hard drives with RAID configurations.
• » Tape drives for backups.

Software Requirements of Clients and Servers

Because  the roles of clients and servers are radically different, the software  requirements of clients and servers are different. Servers will require  software for network administration, and file and data management, among other  things, whereas clients will only require software that will allow them to  connect to the network and use its resources. Clients can also have software  that is used on stand alone PCs, because nowadays, clients in a Client-Server  environment, are usually intelligent  clients or thick clients.

Client Software

Here is some of the software that you might  expect to find on a client:

• » A network operating system for the client - Windows 7, Linux, Apple OS X.
• » Client based applications and groupware software - Lotus Notes, MS Office, Open Office.

Server Software

Here is some of the software that you might  expect to find on a server:

• » A network operating system for the server - Windows Server, Linux Server, UNIX.
• » Server specific software and groupware server software - Lotus Domino Server, MS Exchange Serever, MS SQL Server

Types and Roles of Network Servers

There  are many types of network servers, each having a specific role in the  administration and management of the network's resources. It is entirely  possible for one physical server to be playing the role of two logical servers - one physical server can be both the DNS and DHCP server, and one physical  server can be both the web server and proxy server.

Here is a list of some of the  different types of servers that may be found on a typical network:

• » DNS Server - This is the Domain Name Service server, and is responsible for managing the database of computer to IP address mappings for computers on the network. All networks must have one of these.
• » DHCP Server - This is the Dynamic Host Configuration Protocol server, and it is responsible for assigning IP addresses to computers on the network dynamically.
• » File Server - This server is responsible for managing the files and folders that are used by, and shared among, the users of the network. It controls who has access to what file/folder, and what type of access they have.
• » Print Server - This server's responsibility is to manage the printers on the network, and the different jobs that are sent to the printer. It decides who gets to print what and when.
• » Data Server - This server holds all the data and databases for the company or organisation. It contains all the MySQL, Oracle, and SQL Server databases.
• » Web Server - This server is responsible for managing and maintaining the company's or organisation's web site. It acts as a host for the company's or organisation's web site.

Further Reading

Chapter 1, pp. 2 – 18 of the course text