ppp_async.c. The old ppp.c is still present in the kernel sources but
is not used. If you compile PPP as a module, you will get two
separate modules, called ppp_generic and ppp_async.
+Another module ppp_synctty is used for synchronous tty devices
+such as high-speed WAN adapters for leased T1/E1 lines.
To talk to the new driver, pppd needs to be able to open /dev/ppp,
character device (108,0). If the special file node /dev/ppp is not
to add the following to your /etc/modules.conf or /etc/conf.modules:
alias tty-ldisc-3 ppp_async
+alias tty-ldisc-14 ppp_synctty
alias char-major-108 ppp_generic