Which of the following is a protocol used at the Data Link Layer?

PPP (Point-to-Point Protocol) is a protocol used at the Data Link Layer of the OSI model. It is mainly used to establish a direct connection between two networking devices, like between a computer and an internet service provider over a phone line or serial cable.

PPP helps in sending data over point-to-point links and includes features like:

• Authentication (verifying the user)


• Compression (to make data transmission faster)


• Error detection (to ensure reliable delivery)

PPP is commonly used in older dial-up connections and some WAN technologies. It breaks data into frames and adds headers and trailers so the receiving device can correctly process the data.

Important:

• IP works at the Network Layer


• TCP works at the Transport Layer


• ARP works between Data Link and Network Layers


• PPP works at the Data Link Layer

Conclusion: PPP is a Data Link Layer protocol used for direct communication between two network nodes. It provides basic features like authentication, error checking, and supports multiple protocols.