4.3BSD - /usr/man/cat4/dmc.0

DMC(4)                                                                  DMC(4)


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

SYNOPSIS
       device dmc0 at uba0 csr 167600 vector dmcrint dmcxint

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  infor‐
       mation see the adb script /usr/lib/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  rou‐
       tine.

       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 formatted 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 protocol types may be used.  It is thus incompatible with
       earlier drivers, including the 4.2BSD version.


4.2 Berkeley Distribution        May 21, 1986                           DMC(4)