Data Communication Protocols Flashcards
Data communication protocols are used in telecom to?
transfer digital data from one location to another
Synchronous Transmissions are handled by what layer of OSI Model
Physical Layer
When choosing a standard certain aspects need to be considered:
-throughput
-environment
-length of run
Transmission Types:
-Synchronous
-Asynchronous
Advantages of Asynchronous
-Synchronization happens for each character
-Cheap
-Simple
Disadvantages of Asynchronous
-Large overhead
-Clock drift and framing errors
Methods of Asynchronous Synch
-Bit Synch
-Character Synch
-Frame Synch
In order for info to flow properly both sending and receiving devices have to determine what aspects/properties
- Bits per second
- Data bits
- Parity
- Stop bits
- Flow Control
What does overhead include
Start bits, stop bits, and parity bits
Problems with Asynchronous Bit Synch
- Clock drift
- Framing error
What is clock drift
Clock on the receiver ≠ clock on transmitter
What is framing error a result of
Clock drift or noise
Characteristics of Synchronous Transmission
-Shared clock
-Multiple Bytes
-Clock is encoded in data or
-Clock provided on a separate line
A separate line for clock is used in short distances TRUE or FALSE
True
4 Types of encoding
- AMI (Alternate Mark Inversion)
-HDB3 (High density Bipolar of order 3)
-Manchester Encoding
-Differential Manchester Encoding
