CompSci

Ya

Describe how the data is sent using parallel simplex data transmission.

Describe how the data is sent using parallel simplex data transmission.

Data is sent through several bits through several channels/wires in one direction only

Describe the benefit of using Parallel Half Duplex data transmission.

It is faster compared to Serial & Simplex and allows a two way communication while being cheaper than Full Duplex.

Mention 3 benefit using packet switching

Benefit 1 - There is no need to tie up a single communication line

Benefit 2 - It is possible to overcome failed, busy or faulty lines by re-routing packets

Benefit 3 - A high data transmission rate is possible

Describe how the parity bits are used to detect errors.

They will check the amounts of 1 bits are in a string of binary. If even, the parity bit will be 0 and if its odd, the parity bit will become 1 to compensate. When checking the data, they will see if the string of binary doesnt match the parity bit, it will call it as an error.

State 3 typical of packet structure 

1. Header

2. Payload

3. Trailer

Mention 3 differences serial and parallel data transmission ?     

1. Serial transmission sends one bit at a time while parallel transmission sends several

2. Serial transmission travels through a single channel/wire while parallel transmission travels through several channels/wires

3. Parallel transmission is faster because it sends more bits than Serial

Mention 3 components of Packet Header 

1. IP Address of sender

2. IP address of reciever

3. Size of the packet

Explain how packet switching works when sending 300 Mb data packet from computer A to computer B ?

The data packet will be broken down in the smaller packets which will then follow its own path in going from Computer A to Computer B via routers in nodes. The packets will always go for the shortest path available. Once the packets are reached, the packets will be arranged in ordered according to the information on the header of the packet

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent one bit at a time through one channel in one direction only.

Serial Simplex

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent 16 bit at a time through 16 channels in both directions but not at the same time

Parallel Half Duplex

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent 16 bit at a time through 16 channels in both directions but at the same time

Parallel Full Duplex

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent 8 bit at a time through 8 channel in one direction only.

Parallel Simplex

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent one bit at a time through one channel in both directions at the same time.

Serial Full Duplex

Is this Simplex, Half Duplex or Full Duplex. Also answer if this is Serial and Parallel Transmission:

Data is sent one bit at a time through one channel in both directions but not at the same time.

Serial Half Duplex

A system uses odd parity, indicate if the following binary code will pass or fail:

01010111

Pass

A system uses even parity, indicate if the following binary code will pass or fail:

01010111

Fail

A system uses even parity, indicate if the following binary code will pass or fail:

10100110

Pass

A system uses odd parity, indicate if the following binary code will pass or fail:

10100110

Fail

A system uses odd parity, indicate if the following binary code will pass or fail:

10100111

Pass

A system uses odd parity, indicate if the following binary code will pass or fail:

11111000

Pass

A system uses even parity, indicate if the following binary code will pass or fail:

01111000

Pass

A system uses even parity, indicate if the following binary code will pass or fail:

01111001

Fail

A system uses even parity, indicate if the following binary code will pass or fail:

01101000

Fail

Explain The process how Checksum used for Check the error ?

A block of data is being calculated using an algorithm agreed by the sender and receiver and the checksum will be transmitted along with the block of data. When the receiver receives the block of data, the data will be calculated with the same algorithm. If the calculation is the same, it passes, otherwise the block has errors and will ask for a re-send.

Explain The Process how Echo check used for check the Error ?

When a block of data is sent to the receiver, the receiver will send the block of data back to the sender and the sender will compare the 2 blocks of data if there are any difference and errors.

Mention 3 Error possible when transmit the data

1. Interference

2. Problems during packet switching

3. Skewing of Data

Explain disadvantages using parity bit for check the error ? 

If 2 (or another even number) bits are changed during the transmission, its almost impossible to locate the error.

Mention 3 types of error can be detected by Check Digit

• Incorrect Input Digit

• Transposition Errors

• Ommited or Extra Digits

• Phonetic Errors (ex: Thirteen, Thirty)