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BSD 2.11 - man page for dmc (bsd section 4)

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DMC(4)											   DMC(4)

NAME
       dmc - DEC DMC-11/DMR-11 point-to-point communications device

SYNOPSIS
       /sys/conf/SYSTEM:
	    NDMC dmc_controllers     # DMC11

DESCRIPTION
       The  dmc interface provides access to a point-to-point communications device which runs at
       either 1 Mb/s or 56 Kb/s.  DMC-11's communicate using the DEC DDCMP link layer protocol.

       The dmc interface driver also supports a DEC DMR-11 providing point-to-point communication
       running at data rates from 2.4 Kb/s to 1 Mb/s.  DMR-11's are a more recent design and thus
       are preferred over DMC-11's.  The  NXMT	and  NRCV  constants  in  the  driver  should  be
       increased  in  this  case, as the DMR can accept up to 64 transmit and receive buffers, as
       opposed to 7 for the DMC.

       The configuration flags specify how to set up the device,
       0 -- full duplex DDCMP (normal mode)
       1 -- DDCMP Maintence mode (generally useless)
       2 -- DDCMP Half Duplex, primary station
       3 -- DDCMP Half Duplex, secondary station

       Several device error counters are available via "adb", for more information  see  the  adb
       script /usr/share/adb/dmcstats, or the DMC11 technical manual.

       The  host's  address  must  be  specified  with	an SIOCSIFADDR ioctl, and the destination
       address specified with a SIOCSIFDSTADDR ioctl,  before  the  interface  will  transmit  or
       receive any packets.

ROUTING
       The  driver  places a HOST entry in the kernel routing tables for the address given in the
       SIOCSIFDSTADDR ioctl.  To use the DMC as a link between	local  nets,  the  route  to  the
       remote  net must be added manually with the route(8) command, or by the use of the routing
       process routed(8) on each end of the link.

DIAGNOSTICS
       dmc%d: bad control %o.  A bad parameter was passed to the dmcload routine.

       dmc%d: unknown address type %d.	An input packet was received which contained  a  type  of
       address unknown to the driver.

       DMC fatal error 0%o.  A fatal error in DDMCP occurred, causing the device to be restarted.

       DMC soft error 0%o.  A non-fatal error in DDMCP has occurred.

       dmc%d: af%d not supported.  The interface was handed a message which has addresses format-
       ted in an unsuitable address family.

SEE ALSO
       intro(4N), inet(4F)

BUGS
       The current version of the driver uses a link-level encapsulation so that multiple  proto-
       col types may be used.  It is thus incompatible with earlier drivers, including the 4.2BSD
       version.

3rd Berkeley Distribution		 October 22, 1996				   DMC(4)
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