Compared to MPPP, raw bundling has the advantage that isdn4linux itself can open and close the needed slave channels. Unfortunately raw bundling still has problems with transfer rates. See the further questions below. Accordingly, it inherits all its advantages and disadvantages. In contrast to raw bundling only one net interface is needed as interface to the ipppd, since the ipppd handles all its channels by itself.
Incoming data is distributed round-robin by the ipppd on all available channels.
These channels do not necessarily have to be ISDN channels. In theory, modem connections could be mixed with ISDN channels. However, here we only cover ISDN channels. This is not true for the other encapsulations. First ensure that support for MPPP has been switched on for compilation of your ISDN modules.