1 : A device [Caller] that can communicate with the ADSL modem communicates with the modem and requests a PPOE connection.
2 : The modem initiates the connection with the ADSL authentification server and the ADSL authentification server [telkom] returns a "YouAreValid" handle.
3 : The modem gives the caller device the "YouAreValid" handle, and the caller device sends all future communications through the modem by including the "YouAreValid" handle in the data transmission.
4 : The next comnmunication that the modem recieves that includes the "YouAreValid" handle is sent as data and not a "Please authenticate me" request. The central ADSL server is always verifying the existance of the "YouAreValid" handle, and gathering usage and stats on the account accordingly.
The above is a simplified PPOE communication.
When a modem is in bridge mode, the above is all that it [the modem] can do.
All modems can do this [bridge mode], and some can do so much more.
A router normally hides the bridge mode stuff by running the "Bridging" transparently.
The advantage of a modem running in bridge mode only is that all the communicating devices can innitiate their own PPOE connections concurrently and use their own "YouAreValid" handles, thereboy allowing each communicating device to use their own accounts.
i.e. Each computer connected to the modem MUST initiate it's own PPOE connection, and manage it accordingly.
Summary : Bridge mode = Basic ADSL PPOE capable functionality.
NOTE : We use PPOE, but there are other protocols that can be used to wrap ADSL packets...
