28 Jan 15 - CCNA 4.3

4.3.1  Purpose of the Data Link Layer

 The Data Link Layer is responsible for the exchange of frames between nodes over a physical network media.

It performs two specific services:

• Accepts Layer 3 packets and packages them into frames
• Controls media access control and performs error detection

4.3.1.2  Data Link Layer is divided into 2 Sublayers:

Logical Link Control (LLC)
Media Access Control (MAC)

Watch this.  It concisely explains 4.3.1.2 -4.3.1.4