2 .\" Copyright (c) 1997, 1999 Hellmuth Michaelis. All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, are permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
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13 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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25 .\" $Id: i4bipr.4,v 1.11 1999/12/13 22:11:55 hm Exp $
27 .\" $FreeBSD: src/usr.sbin/i4b/man/i4bipr.4,v 1.7.2.5 2003/03/13 03:10:59 trhodes Exp $
29 .\" last edit-date: [Mon Dec 13 23:10:25 1999]
36 .Nd isdn4bsd IP over ISDN B-channel network driver
38 .Cd pseudo-device \&"i4bipr\&" Op count
44 driver interfaces the IP subsystem of the operating system with the
45 isdn4bsd package so that transport of IP packets over an ISDN link
48 The driver just packs IP packets without anything appended or prepended
49 into raw HDLC packets on the B channel and transfers them to a remote site.
50 IP packets received from the remote site are queued into the local IP
53 The format of the resulting packet on the B channel is:
55 .Dl (HDLC opening flag) (IP-packet) (CRC) (HDLC closing flag)
57 In the case where an IP packet for a remote site arrives in the driver and no
58 connection has been established yet, the driver communicates with the
60 daemon to establish a connection.
62 The driver has support for interfacing to the
70 The driver optionally (when compiled with the IPR_VJ option) provides Van
71 Jacobsen header compression, under control of the link0 and link1 options to
74 .Bl -tag -width 15n -offset indent -compact
76 Apply VJ compression to outgoing packets on this interface, and assume that
77 incoming packets require decompression.
79 Check incoming packets for Van Jacobsen compression; if they appear to be
80 compressed, automatically set link0.
83 The default values are
99 device driver and this manpage were written by
100 .An Hellmuth Michaelis Aq hm@FreeBSD.org .