Point-to-Point Protocol over ATM
From Free net encyclopedia
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