Dcf255 Test 1 Review Study Guide Rated A+

Data framing {Ans: The data link layer is responsible for the final encapsulation of higher-level messages into frames so it can be sent across a single switched network by the physical layer. And the synchronization of machines at each end of the link}Common transmission errors {Ans: noise, crosstalk, emi, jitter}Types of error correction {Ans: Backwards error correct, forwards ec}Path chose to send datagram {Ans: route}Simplex {Ans: the data can only travel in one direction receive or send, but not both}CRC divisor {Ans: The receiver performs a division operation using the same CRC divisor. If the remainder contains all zeros the data bits are accepted, otherwise it is considered as there some data corruption occurred in transit. The CRC seems complicated and slow, but it is very fast because it is built into the hardware. It all has the lowest overhead, less than 1% ( 16 check bits for a transmission of 1500 bytes). Lastly, studies have shown that the CRC can detect 99.99% of all errors.}