MODEM
A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms.
Fortunately, there is one standard interface for connecting external modems to computers called RS-232. Consequently, any external modem can be attached to any computer that has an RS-232 port, which almost all personal computers have. There are also modems that come as an expansion board that you can insert into a vacant expansion slot. These are sometimes called on board or internal modems.
While the modem interfaces are standardized, a number of different protocols for formatting data to be transmitted over telephone lines exist. Some, like CCITT V.34, are official standards, while others have been developed by private companies. Most modems have built-in support for the more common protocols -- at slow data transmission speeds at least, most modems can communicate with each other. At high transmission speeds, however, the protocols are less standardized.
Aside from the transmission protocols that they support, the following characteristics distinguish one modem from another:
SECURITY MONITOR
To ensure that all files are sent and received free from any form of threat security, antivirus and filter malicious codes should be updated from time to time.
Data and network to be controlled from:
Performance invalid ~ control can be done using verification (authentication) as the user identification code / password and encryption
The virus' code introduced illegally can destroy the system. Data & network should be protected from viruses by using hardware and software specifically designed for the purpose. (Firewall)
~ Disaster Data & network should be preserved from disasters such as theft, fire, earthquake, flood and other. Maintenance are also can be done by performing a backup.
Authentication
Verify the sender of a message.
It verifies the identity of the user who will reach the resources that are available in data communication .
Authentication can be done using the password. Says - password
Form of security that is often used .
It is required by the host computer or certain devices to verify identity before entering the system.
There are three methods of authentication using the password :
Something owned ( Something Possessed )
An inherent ( Something embodied )
An unknown ( Something known ) .
Password
- Check the identity of a computer system in 2 ways.
- password
Something that belonged to the identification scheme .
- Example : password ( pin number ) used in conjunction with an ATM card or a smart card.
Password
- Something embodied Involved the examination of the users to the unique characteristics found on a user .
- This procedure is ideal for tight security system where threats to the system can cause severe consequences because the cost is high.
- Example: voice recognition , finger print, the pattern of eyes / retinal pattern, and a digital signature.
Password ~ something known
- In this method , by asking for a password , the computer system will also ask questions related to the agent ( user) .
- Example: questions such as date of birth, mother's maiden name , identity card number and others.
Types of Password
- Password issued by the user ~ users to create their own password .
- Password issued by the computer ~ computer produces a random password .
- Tunable password ' compromise between password issued by the user and the computer. Computer users have a password and use it to create a new password etc.
