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.\" $OpenBSD: dmc.4,v 1.7 2001/11/13 13:54:26 mpech Exp $
.\" $NetBSD: dmc.4,v 1.3 1996/03/03 17:13:22 thorpej Exp $
.\"
.\" Copyright (c) 1983, 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" from: @(#)dmc.4 6.5 (Berkeley) 3/27/91
.\"
.Dd March 27, 1991
.Dt DMC 4 vax
.Os
.Sh NAME
.Nm dmc
.Nd
.Tn DEC
.Tn DMC-11 Ns / Tn DMR-11
point-to-point communications device
.Sh SYNOPSIS
.Cd "device dmc0 at uba0 csr 167600 vector dmcrint dmcxint"
.Sh DESCRIPTION
The
.Nm dmc
interface provides access to a point-to-point communications
device which runs at either 1 Mb/s or 56 Kb/s.
.Tn DMC-11 Ns s
communicate
using the
.Tn DEC DDCMP
link layer protocol.
.Pp
The
.Nm dmc
interface driver also supports a
.Tn DEC
.Tn DMR-11
providing point-to-point
communication running at data rates from 2.4 Kb/s to 1 Mb/s.
.Tn DMR-11 Ns s
are a more recent design and thus are preferred over
.Tn DMC-11 Ns s .
The
.Dv NXMT
and
.Dv NRCV
constants in the driver may be increased in this case,
as the
.Tn DMR
can accept up to 64 transmit and receive buffers, as opposed
to 7 for the
.Tn DMC .
.Pp
The configuration flags specify how to set up the device,
.Bl -column xxx -offset indent
0 full duplex DDCMP (normal mode)
1 DDCMP Maintenance mode (generally useless)
2 DDCMP Half Duplex, primary station
3 DDCMP Half Duplex, secondary station
.El
.Pp
Several device error counters are available via
.Xr adb 1 ,
for
more information see the
.Em adb
script
.Pa /usr/lib/adb/dmcstats ,
or the
.Tn DMC-11
technical manual.
.Pp
The host's address must be specified with an
.Dv SIOCSIFADDR
.Xr ioctl 2 ,
and the destination address specified with a
.Dv SIOCSIFDSTADDR
.Xr ioctl 2 ,
before the interface will transmit or receive any packets.
.Sh ROUTING
The driver places a
.Tn HOST
entry in the kernel routing tables for the
address given in the
.Dv SIOCSIFDSTADDR
.Xr ioctl 2 .
To use the
.Tn DMC
as a
link between local nets, the route to the remote net must be added manually
with the
.Xr route 8
command, or by the use of the routing process
.Xr routed 8
on each end of the link.
.Sh DIAGNOSTICS
.Bl -diag
.It dmc%d: bad control %o.
A bad parameter was passed to the
.Em dmcload
routine.
.Pp
.It dmc%d: unknown address type %d.
An input packet was received which contained a type of
address unknown to the driver.
.Pp
.It DMC fatal error 0%o.
A fatal error in
.Tn DDMCP
occurred, causing the device to be restarted.
.Pp
.It DMC soft error 0%o.
A non-fatal error in
.Tn DDMCP
has occurred.
.Pp
.It dmc%d: af%d not supported.
The interface was handed a message which has
addresses formatted in an unsuitable address family.
.El
.Sh SEE ALSO
.Xr inet 4 ,
.Xr intro 4
.Sh HISTORY
The
.Nm
driver appeared in
.Bx 4.2 .
.Sh BUGS
The current version of the driver uses a link-level encapsulation
so that multiple protocol types may be used.
It is thus incompatible with earlier drivers,
including the
.Bx 4.2
version.
|
