Difference between BISYNC and HDLC features

BISYNC: BISYNC stands for Binary Synchronous Communication. It is a half-duplex link protocol that replaces the SRT which stands for Synchronous transmit-receive. 

HDLC: HDLC stands for High-Level Data Link Control. It works on the data link layer of the OSI reference model. It supports both connection-oriented and connection less services. 

Similarities between BISYNC and HDLC:

• Both BISYNC and HDLC are synchronous communication protocols that transmit data in a continuous stream of bits.
• Both protocols include error detection mechanisms, such as CRCs, to ensure the integrity of the transmitted data.
• Both protocols support flow control mechanisms to regulate the rate of data transmission and prevent data loss.
• Both protocols use framing mechanisms to divide the data into packets for transmission.
• Both protocols are widely used in data communication networks.

Features of HDLC and BISYNC :

BISYNC Features	HDLC Features
It supports serial transmission.	It also supports serial transmission.
Communication mode of BISYNC is synchronous.	Communication mode of HDLC is both synchronous and asynchronous.
It uses TWA directional mode.	It uses TWA and TWS directional mode.
It supports both point to point and point to multipoint configuration.	It also supports both point to point and point to multipoint configuration.
It follows stop and wait flow control protocol.	It follows sliding window flow control protocol.
To content errors it uses LRC/CRC method.	To content errors it uses CRC method.
It uses SYN SYN frame identifier in framing.	It uses Flag frame identifier in framing.
EBT/ETX frame delimiter in framing.	Flag frame delimiter in framing.
Multiple bytes information field in framing.	Multiple bits information field in framing.
For Framing transparency it follows DLE stuffing.	For Framing transparency it follows ZERO stuffing.

Conclusion :

BISYNC and HDLC are two different communication protocols that differ in several key features, including framing, data link control, transmission modes, error detection and correction, network topologies, and bit stuffing. While both protocols were commonly used in the past for data transmission between computer systems, HDLC is still widely used today in various applications such as telecommunications and networking.