Tuesday, January 6, 2009

Datacom-HW1

General Types of Modem

1. Internal - Modem which would be plugged into a slot located within.- Fit inside of the computer

2. External-Modem which is located within a box and is hooked up externally to the computer.

Specific Types of Modem
1. Optical Modem
2. Short Haul Modem
3. Acoustic Modem
4. Short Modem
5. Digital modem
6. V.32

Difference Between Band Speed and bps

Bps is the accurate measure of the speed of communication. It represents the number of bits transmitted per second

Difference Between Serial Communication and Parallel Communication The difference is that serial transmissions only use 2 wires for transmitting and receiving data, and only 1 for sending or receiving, and can only send one bit at a time. Serial ports are a type of computer interface that complies with the RS-232 standard. They are 9-pin connectors that relay information, incoming or outgoing, one byte at a time. Each byte is broken up into a series of eight bits, hence the term serial port. Serial ports only supported 115 kilobits per second (kbps) which was later improved technology pushed serial port speeds to 460 kbps.Serial ports are one of the oldest types of interface standards. Computer mice and even keyboards also used serial ports. Some serial ports used 25-pin connectors, but the 9-pin variety was more common. Paralle Port is 25-pin. Parallel ports transmit one byte at a time by using eight parallel wires that each carry one bit. With data traveling in parallel, the transfer rate was greater. A parallel port could support rates up to 100 kilobytes per second.. Parallel cables use several wires for data transmission and is much faster than serial thus 8 or more wires are carrying data parallel to each other to it's destination