Enter your search terms Submit search form
	Web pdp-10.trailing-edge.com

                     DECnet-20 Beware File

                           March 1982

                           VERSION 2.1




                          AA-J693B-TM

























COPYRIGHT (C) 1979,1982 BY
DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.


THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY BE USED  AND
COPIED  ONLY  IN  ACCORDANCE WITH THE TERMS OF SUCH LICENSE AND
WITH  THE  INCLUSION  OF  THE  ABOVE  COPYRIGHT  NOTICE.   THIS
SOFTWARE  OR  ANY  OTHER  COPIES THEREOF MAY NOT BE PROVIDED OR
OTHERWISE MADE AVAILABLE TO ANY OTHER PERSON.  NO TITLE TO  AND
OWNERSHIP OF THE SOFTWARE IS HEREBY TRANSFERRED.

THE INFORMATION IN THIS SOFTWARE IS SUBJECT TO  CHANGE  WITHOUT
NOTICE  AND  SHOULD NOT BE CONSTRUED AS A COMMITMENT BY DIGITAL
EQUIPMENT CORPORATION.

DIGITAL ASSUMES NO RESPONSIBILITY FOR THE USE OR RELIABILITY OF
ITS SOFTWARE ON EQUIPMENT WHICH IS NOT SUPPLIED BY DIGITAL.

DECnet-20 V2.1 Beware File                               Page 2


1.0  GENERAL INFORMATION

     Decnet-20  V2.1   is  a  Maintenance  Release  for   DECsystems
2040/2050/2060 only.  RJE V1.0 is compatible with DECnet20-V2.1.



1.1  Installation of 32K Word DN20s

     DECnet-20 V2.1 for DN20s with only 32K words of memory requires
special generation procedures, which are documented in the appendix.

     DN20 systems with 32K words have no  additional maintainability
features  other  than what was available in DECnet-20 V1.  Thus, NCP
(Network  Control  Program) commands  such as  "SHOW {COUNTS|STATUS}
KNOWN LINES"  and  "SET  STATE LINE line-id", which were unavailable
for DECnet-20 V1, will not work for  32K configurations in DECnet-20
V2.1.



2.0  BEWARE ITEMS


2.1  Acceptance Procedures

     When running  the DECnet-20  acceptance  tests,  AUTO-DUMP  and
AUTO-LOAD for the DN20 front end must be disabled.  Failure to do so
will prevent  operation of  the loopback tests.  Any  "node OFFLINE"
operator  messages  that appear  during the loopback  test should be
ignored.


2.2  DN20 System Cannot be Loaded if Generated Incorrectly

     The hardware  configuration  options  specified  for  the  DN20 
system image during network generation must be installed on the DN20
hardware  for  the  system  image  to  be  successfully  loaded.  If 
hardware is specified  that does not exist, the DN20 node will crash
a few seconds after it is loaded.  It  is  important to know exactly
what line interfaces are installed on the DN20 and generate the DN20
software  for no  more than  this.  If you  plan to  get  more  line
interfaces in  the near  future, you  cannot generate  them ahead of
time.

     Failure to adhere to this restriction will  prevent  successful
installation of DECnet-20.


2.3  DN20 Crashes When Node Initialization is to Itself

     If the DN20 attempts  to node initialize over a line that is in
loopback,  it will crash.  The crash could be caused by installing a
loopback connector or by placing a  modem in loopback on a line that  
is in the ON state.  See the suggestions section of the DOC file for
the proper method of performing line loopback.

DECnet-20 V2.1 Beware File                               Page 3


2.4  KMC/DUP Problem

     There  is  a known  problem  with the  KMC/DUP  hardware.   The
symptoms are  that the KMC/DUP line becomes 'hung' and investigation
of the EIA interface reveals that  the  DN20  has Request-to-Send up
continuously.  The problem is likely to happen whenever the modem on
the KMC/DUP line is powered on/off or is  disconnected with the line
in the ON state.

     To prevent this problem from happening, turn the line  off with
the  SET STATE LINE line-id OFF  command  prior  to disconnecting or
powering off a modem on any  line.   The  line can then be turned on
again when the modem is reconnected.

     The simplest way to recover from this problem, should it occur,
is to reload the DN20.


2.5  DN20 crashes when Transmit Password is changed in NETGEN.

     When doing a NETGEN for the DN20, the Transmit Password must be
DECNET20  (default).  If this  password  is changed, the  DN20  will
crash a few seconds  after it finishes loading.  Adjacent nodes that
require Node Verification must change their Receive Password for the
DECnet-20 node to DECNET20.


2.6  CLOSE problem.

     The exec 'CLOSE' command does not close an aborted DECnet link,
however, the exec 'PUSH' command does close the link.


2.7  GNJFN% problem.

     The GNJFN% JSYS does not step through directories correctly.


2.8  Loopback for local DMC.

     The loopback test for  the local DMC11 (DN21-BB) does not work.
The DN21-BB  is a 56kbps integral  line unit, includes  one DMC11-AL
IPL microprocessor, once DMC11-MD line unit with integral modem, and 
one BC03N-A0 coaxial cable.

DECnet-20 V2.1 Beware File                               Page 4










                          APPENDIX A

        NETWORK GENERATION OF DECnet-20 V2.1 FOR 32K DN20



A.1  OVERVIEW

     A 32K DN20  has marginal  memory capacity for running DECnet-20
V2.1.  To  maintain  most  DECnet-20  V1 functionality,  the 72-hour
testing (TEST72) capability on a production system has been dropped.
Consequently, users having a 32K DN20 will need to generate two DN20
systems, one for  use during the  acceptance procedures, and another
for use during production.

     The acceptance procedure  involving UETP  (executing in the KL)
and TEST72 (executing in the DN20) can be run only by loading a DN20
that  has  TEST72   configured  and  does   not  have  the  Topology
Notification capability.   Likewise,  a production DN20 system  must
have the  Topology  Notification capability and must not have TEST72 
configured.


A.2  CONFIGURATION CONSTRAINTS

     There are constraints on configuration options for a  32K DN20.
The  configuration  options are selected by commands to the  NETGEN
program.  The only supported 32K DN20 parameter values are:

      o  HARDWARE - Either 1 DUP11  (not a KMC-DUP  combination) or
         1  DMC11.  [Note:  this does  NOT mean that you cannot run
	 a DN20 that has KMC-DUP hardware installed, just  that the
	 KMC must not be configured.]

      o  SOFTWARE - 20 CCBs, 12 RDBs, and 8 SDBs;  all other values
         must  be  defaulted.  The  only  exceptions  to  this  are
	 identification  parameters such  as password,   node-name,
	 and node-number.

NETWORK GENERATION OF DECnet-20 V2.1 FOR 32K DN20      Page A-2


A.3  EXAMPLES OF NETGEN TYPE-INS

     During the generation procedure, it is advised that you create
a  separate  directory  for  each  configuration  to eliminate  any 
confusion.  Examples of various configuration sessions  are offered
below.



A.3.1  Acceptance Procedure Configuration


@RUN NETGEN
TOPS-20 Network Configurator for DN2x or DN200, Version: V2.1.2-39
NETGEN>EXCLUDE (from Configuration) KDP (number) 0
NETGEN>INCLUDE (in Configuration) DUP11 (number) 0
NETGEN>CCBS 20
NETGEN>RDBS 12
NETGEN>SDBS 8
NETGEN>EXCLUDE (from Configuration) TASK (type) Topology-Notification 
NETGEN>SAVE ACC32K
NETGEN>FINISH
NETGEN>EXIT
@




A.3.2  Production Configuration


@RUN NETGEN
TOPS-20 Network Configurator for DN2x or DN200, Version: V2.1.2-39
NETGEN>EXCLUDE (from Configuration) KDP (number) 0
NETGEN>INCLUDE (in Configuration) DUP11 (number) 0
NETGEN>CCBS 20
NETGEN>RDBS 12
NETGEN>SDBS 8
NETGEN>EXCLUDE (from Configuration) TASK (type) 72-Hour-Test 
NETGEN>SAVE PRO32K
NETGEN>FINISH
NETGEN>EXIT
@