MODULE 6: Additional Layers and Protocols Point-to-Point Protocol Now that we've covered the main OSI Model layers, we're going to examine some additional protocols, and we begin with Point to Point Protocol. You'll learn the definition of Point-to-Point Protocol and the lower level protocols, what HTCL is and how they allow communication between proprietary systems. You'll learn how PPP authenticates user, how it performs compression, and what components its compresses and how that impacts bandwidth. We'll also discuss now PPP can view multiple links as one entity and when that occurs. And we'll also explain the difference between Network Control Protocol (NCP) and Internet Protocol Control Protocol (IPCP) and which is in use today.