PPPOA or PPPoA, Point-to-Point Protocol (PPP) over ATM, is a network protocol for encapsulating PPP frames in ATM AAL5. It is used mainly with cable modem, DSL and ADSL services.

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.

PPPoA is specified in RFC 2364.

To configure PPPoA on a Cisco router providing DSL services, a "Virtual-Template" is configured, which is then bound to the ATM interface. A configuration snippet is below:

 Interface Virtual-Template1
 IP unnumbered FastEthernet0/0
 Peer default ip address pool dslPPP
 PPP authentication pap
interface ATM1/0.32 point-to-point
 pvc 1/32 
  ubr 640
  encapsulation aal5mux ppp Virtual-Template1

See also

• L2TP

External links

• A typical PPPoA architecture diagram
• RFC2364

Tunneling protocols

PPPoA | PPPoA | PPPoA | PPPoA