Ref: 02550004
Title: Differentiating Between IB/3s with MCPU-10 and MCPU-20 Processors
Date: 01/24/90

Copyright 3Com Corporation, 1991.  All rights reserved.

Currently, IB/3s are shipped with MCPU-20 processors.  In the past,
to provide an inexpensive upgrade from a GS/3 or a GS/3-M (the
first remote IB built upon a GS/3 platform), 3Com provided a firmware-
and software-only upgrade.  After the upgrade was installed, the unit
was an MCPU-10 or MCPU-12 based IB/3.

This article explains the difference between the two types of IBs and
warns of incompatibilities between some versions of software.


MCPU-10 or MCPU-12 Based IB/3:

Runs SW/IB3 Version 10000 (ONLY!) - SW/IB3 Version 10000 is 83-0142-00,
the Topsoft is 21-0075-00; both are obsolete, but replacement copies of
the software are available from 3Com's RMA department.

Must have, except where noted, the specified firmware with the boards
listed below.  When two firmware part numbers are shown separated by a
"/", both pieces of firmware are required.

Board and Part Number                Firmware and Part Number
---------------------                ------------------------
MCPU-10 (06-0008-02)                 M1MMON Rev.02B (36-0004-18/19)*
or MCPU-12 (06-0008-05)

IEC/M aka EC/2 (06-0021-00)          M1EC2B Rev.01A (36-0005-37/38)*

SIOs**                               M1SYNC Rev.01G (36-0005-33/34)***

ITC/M (06-0051-00)**                 (No PROMs needed)

Both the MCPU-10 or MCPU-20 and an IEC/M must be installed in
an IB/3 running SW/IB3 Version 10000, which is the last version
of software scheduled for MCPU-10 or MCPU-12 based IB/3s.

*     Both the M1MMON Rev.02B (36-0004-18/19) and the M1EC2B
      Rev.01A (36-0005-37/38) are obsolete, but are available
      from 3Com's RMA department.

**    SIO Modules that may be installed include the SIO-SMS,
      SIO-422S, and SIO-V.35S.  The ITC/M is a T-1 Controller and,
      if present, is installed in one of the slots E through H in
      the Series/1 Chassis.  See the Internetwork Bridge Installation
      and Operation Guide for more information.  There are limits on
      the number of SIOs and ITC/Ms that may be installed in MCPU-10
      or MCPU-12 based IB/3s.

***   Rev.01G is the current revision of M1SYNC EPROMs; an IB/3
      running SW/IB3 may have M1SYNC Rev.01D or later installed in
      its SIOs.


MCPU20-Based IB/3s

Must have, except where noted, the specified firmware with the boards
listed below.

Board and Part Number                Firmware and Part Number
---------------------                ------------------------
MCPU-20 (06-0044-00)                 M3MMON Rev.00J (36-0008-00)*

IEC/M aka EC/2 (06-0021-07)**        M1IECM Rev.02A (36-0005-35/36)**

SIOs***                              M1SYNC Rev.01G (36-0005-33/34)****

ITC/M (06-0051-00)***                (No PROMs needed)

The MCPU-20 has a 68020 CPU clocked at 16 MHz.  Software that may be
run includes SW/20-IB Versions 10000, 11000, and 2.0 (or later).

*    MCPU-20 based IB/3s running SW/20-IB Version 10000 may have
     M3MMON Rev.00D EPROMs installed; all later versions require
     M3MMON Rev.00J or later.

**   The installed IEC/M may have part number 06-0021-03, 06-0021-06,
     or 06-0021-07, but must have M1IECM Rev.02A EPROMs installed
     unless the IB/3 is running SW/20-IB Version 10000.  If running
     SW/20-IB Version 10000, the IEC/M may have M1EC2B Rev.01A
     P/N (36-0005-37/38) installed; SW/20-IB Version 11000 and 2.0
     or later require that M1IECM Rev.02A or later be installed in the
     IEC/M.  A Broadband Controller (IBC/M) may be installed in place
     of the IEC/M for broadband applications; see the Internetwork
     Bridge Installation and Operation Guide for more information.

***  SIO Modules that may be installed include the SIO-SMS, SIO-422S,
     and SIO-V.35S.  The ITC/M is a T-1 Controller and, if present, is
     installed in one of the slots E through H in the Series/1 Chassis.
     See the Internetwork Bridge Installation and Operation Guide for
     more information.

**** Rev.01G is the current revision of M1SYNC EPROMs.  MCPU-20 based
     IB/3s may have M1SYNC Rev.01D EPROMs installed if running SW/20-IB
     Version 10000; all later versions require M1SYNC Rev.01G or later.


SOFTWARE INCOMPATIBILITIES

1.  SW/20-IB Version 2.0 or later requires that an IB/3 attached
by serial link to an IB/3 with Version 2.0 or later, also run
Version 2.0 or later.  Otherwise, the IB/3s may indicate that the
line is up and the other end is reachable but may fail to pass user
data.

2.  To keep up a serial line between an IB/3 running SW/20-IB
Version 11000 and an IB/3 running SW/20-IB Version 10000 or SW/IB3
Verison 10000, set the ErrorRate parameter (available in 11000) for
the path connecting the two IB/3s to 100.