- Point-to-Point Protocol (PPP); The user or machine
sends a request to a Network Access Server (NAS) to gain access
to a particular network resource using access credentials. The credentials
are passed to the NAS device via the data link layer (L2) protocol—for
example, Point-to-Point Protocol (PPP) in the case of many dial
up or DSL providers or posted in an HTTPS secure web form.
- Protocol Packet Processing (PPP)