PADI, PADO, PADR, PADS, and PADT?
PPPoE requires certain signals and information to establish, accept, control and terminate the session. The basic signalling is shown below. A PADI (PPPoE Active Discovery Initiation) broadcast signal is sent by the host to the remote devices. A PADO (PPPoE Active Discovery Offer) signal is sent by the remote device back to the host. A PADR (PPPoE Active Discovery Request) unicast signal is sent by the host to the remote device. A PADS (PPPoE Active Discovery Session-Confirmation) is sent by the remote device back to the host. A PADT (PPPoE Active Discovery Terminate) signal is sent to terminate a PPPoE session. It is the proper way to terminate a session but is not the actual cause for the termination. The cause may be a simple timeout, a manual request by either end, or an out of spec line condition. »docs.hp.com/en/5971-4750/ch01s03.
