Computer network (ii) Data link layer

I. Overview

1. Node: host, router; link: the communication channel that connects the neighboring nodes along the communication path. Data Link: In addition to the physical link, there must also be a communication protocol to control the transmission of these data. Adding the hardware and software that implements these protocols to the link constitutes a data link. Frame:

2. The data link layer is implemented on the Ethernet card .

3. link Layer main functions : Link Management, package frame, flow control, error control, transparent transmission.

Package into frames: frame-end bound.

Transparent transport: Use the byte Fill method to solve the transparent transmission problem.

Error detection: Bit error rate, redundant checksum code CRC.

4.2 Types of Links: Point-to-point, broadcast (shared line or medium).

Two.

Computer network (ii) Data link layer