The Care and Feeding of ISDN4BSD
12.7 300 Baud Soft-Modem	The Care and Feeding	13.1 Outgoing ppp connections

13 Setting up i4b and userland ppp(8)

Since isdn4bsd beta-release 0.83, i4b supports incoming and outgoing PPP connections using the userland ppp(8) package from Brian Somers.

To learn more about userland PPP, have a look at http://www.Awfulhak.org/ppp.html and read the manual page for ppp(8).