CHARACTER ORIENTED PROTOCOL Flashcards
(17 cards)
Is a Data Link layer function whereby the packets from
the Network Layer are encapsulated into frames. The
data frames can be of fixed length or variable length.
In variable - length framing, the size of each frame to
be transmitted may be different. So, a pattern of bits
is used as a delimiter to mark the end of one frame
and the beginning of the next frame
Framing
data is transmitted as a sequence of bytes,
from an 8-bit coding system like ASCII.
Character - Oriented Framing
The parts of a frame in a character - oriented framing are
Frame Header, Payload field, Trailer, Flags
It contains the source and the destination
addresses of the frame in form of bytes
Frame Header
It contains the message to be delivered. It is a
variable sequence of data bytes.
Payload field
It contains the bytes for error detection and error
correction.
Trailer
are the frame delimiters signalling the start and end
of the frame. It is of 1- byte denoting a protocol - dependent
special character
Flags
depends on the binary code of a character set. The code generally used is ASCII (American Standard Code for Information Interchange).
Character-Oriented Protocol
ASCII
American Standard Code for Information Interchange
It is a 7-bit code with an eighth bit used for parity. The code has 128
characters, of which 95 are graphic characters and 33 are control
characters
ASCII
Number of character that ASCII has
128
Number of Graphic character that ASCII has
95
Number of Control Characters that ACII has
33
involves the upper and lowercase letters, the
ten numerals, and multiple unique symbols
graphic characters
are used to route information, organizing the test in the desired
structure, and for the design of the printed page.
Control Characters
The characters that control the transmission
are known as
communication control characters
Each character has a 7-bit code and is defined by a three-letter symbol.
communication control characters
