Title Unit 6 - Data Link Layer - Data Communication and Computer Network.pdf ✅

www.ckundan.com.np 4 3. Starting And Ending Flags, With Bit Stuffing: The third method allows data frames to contain an arbitrary number of bits and allows character codes with an arbitrary number of bits per character. At the start and end of each frame is a flag byte consisting of the special bit pattern 01111110. Whenever the sender's data link layer encounters five consecutive 1s in the data, it automatically stuffs a zero bit into the outgoing bitstream. This technique is called bit stuffing. When the receiver sees five consecutive 1s in the incoming data stream, followed by a zero bit, it automatically de-stuffs the 0 bit. The boundary between two frames can be determined by locating the flag pattern. 4. Physical Layer Coding Violations: The final framing method is physical layer coding violations and is applicable to networks in which the encoding on the physical medium contains some redundancy. In such cases normally, a 1 bit is a high-low pair and a 0 bit is a low-high pair. The combinations of low- low and high-high which are not used for data may be used for marking frame boundaries. Fig: Physical Layer Coding Violations Basics of Error Detection and Correction: Error is a condition when the output information does not match with the input information. There can be various reasons that the transmission error occurs. Possible