Point-to-Point Protocol over ATM
（重定向自PPPOA）
In computer networking, the Point-to-Point Protocol over ATM (PPPoA) is a layer 2 data-link protocol typically used to connect domestic broadband modems to ISPs via phone lines.
It is used mainly with DOCSIS and DSL carriers, by encapsulating PPP frames in AAL5. It offers standard PPP features such as authentication, encryption, and compression. If it is used as the connection encapsulation method on an ATM based network it can reduce overhead slightly (around 0.58%) in comparison to PPPoE. It also avoids the issues that PPPoE suffers from, related to having a MTU lower than that of standard Ethernet transmission protocols. It also supports (as does PPPoE) the encapsulation types: VC-MUX and LLC based.