Three basic problems of data link layer of computer network

1. Packaged into frames

refers to adding a header and tail before and after a piece of data, which makes up a frame.

2. Transparent transmission.

The start and end of a frame is marked with a specially specified control character. As the beginning with Soh, end with EOT.

3. Error detection.

Bits may have errors in the transmission: 1 May become 0, and 0 may become 1, which is a bit error. At present, the CRC error detection technique is widely used in the data link layer for cyclic redundancy testing.