Like described, PPP is a suite of protocols that takes care of the following, using the related individual protocol:
- Checks the integrity of the medium -i.e. phone line- (LCP)
- Authenticates (PAP/CHAP)
- Assigns an IP address to your end (IPCP)
- Negotiates a few other properties, like maximum packet size and compression -distinguishable through it's header fields- and encapsulates all data for the connection session.
- Negotiates disconnection