Which protocol is an example of the Data Link Layer (Layer 2)?

The Point-to-Point Tunneling Protocol (PPTP) is indeed associated with the Data Link Layer (Layer 2) in network architecture. This protocol is used primarily for establishing secure connections over the internet by encapsulating Point-to-Point Protocol (PPP) frames in a secure manner, facilitating the transmission of data at Layer 2 without concern for the intricacies of IP routing.

In contrast, the other protocols present provide functionalities above Layer 2. The Internet Protocol (IP) operates at Layer 3, which is responsible for routing packets across networks. The Transmission Control Protocol (TCP) functions at Layer 4, providing reliable, ordered delivery of a stream of data between applications. The File Transfer Protocol (FTP) operates at the application layer, focusing on the transfer of files between client and server without addressing the lower-level protocols.

Understanding the specific layers of the OSI model is crucial for recognizing how various protocols function within a network, where PPTP exemplifies the Data Link Layer by handling encapsulation and transmission of data frames.