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.\" Copyright (c) 1997, 1999 Hellmuth Michaelis. All rights reserved.
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.\"	$Id: i4bisppp.4,v 1.12 1999/12/13 22:11:55 hm Exp $
.\"
.\" $FreeBSD$
.\"
.\"	last edit-date: [Mon Dec 13 23:11:15 1999]
.\"
.Dd December 22, 1998
.Dt I4BISPPP 4
.Os
.Sh NAME
.Nm i4bisppp
.Nd isdn4bsd synchronous PPP over ISDN B-channel network driver
.Sh FreeBSD SYNOPSIS
.Cd pseudo-device \&"i4bisppp\&" Op count
.Sh NetBSD SYNOPSIS
none
.Sh DESCRIPTION
The
.Nm
driver interfaces the IP subsystem of the operating system with the 
isdn4bsd package so that a transport of IP packets over an ISDN link
is possible.
.Pp
The driver is just a glue layer between Serge Vakulenko's sppp 
backend and the ISDN4BSD package.
.Pp
In case an IP packet for a remote side arrives in the driver and no
connection is established yet, the driver communicates with the
.Xr isdnd 8
daemon to establish a connection.
.Pp
The driver has support for interfacing to the
.Xr bpf 4
subsystem for using
.Xr tcpdump 1
with the
.Nm isp
interfaces.
.Pp
The 
.Xr spppcontrol 8
utility is used to configure all aspects of PPP required to connect to a
remote site.
.Sh LINK0 and LINK1
The
.Em link0
and 
.Em link1
flags given as parameters to
.Xr ifconfig 8
have the following meaning for the
.Nm isp
devices:
.Bl -tag -width link0 -compact
.Pp
.It Li link0 
wait passively for connection
.Pp
.It Li link1
auto-dial on output
.El
.Pp
The 
.Em link0 
and 
.Em link1 
flags are set to
.Em off
by default.
.Pp
See
.Xr sppp 4
for a more detailed discussion of the flags,
.Pp
.Sh SEE ALSO
.Xr isdnd 8
.Xr isdnd.rc 5
.Xr spppcontrol 8
.Xr sppp 4
.Xr bpf 4
.Xr tcpdump 1
.Sh AUTHOR
The
.Nm
device driver was written by 
.An Joerg Wunsch 
and then added to ISDN4BSD by 
.An Gary Jennejohn .
This manpage was written by 
.An Hellmuth Michaelis Aq hm@kts.org .