Ref: 02550006
Title: IB/3 Performance Running SW/20-IB Version 2.0
Date: 01/29/90

Copyright 3Com Corporation, 1991.  All rights reserved.

A pair of IB/3s running SW/20-IB Version 2.0 will filter up to
19,000 packets per second, 9,500 in each direction, and is
capable of forwarding up to 3,000 packets per second.  These
figures are based upon minimum sized packets.  The major limiting
factors are serial link line speed and packet size.  A better
figure to use is the raw data maximum throughput of 3.7 Mbps.

Using 64 bytes as the minimum packet size, a throughput rate of
3000 packets per second is approximately 1.5 Mbps, due to the processor
overhead associated with forwarding a packet.  3Com has not tested
other packet sizes for this version of software, but it is calculated
that the optimal packet size is approximately 200 bytes, as shown in
the table below.

Under optimal conditions and configuration, the following forwarding
values are calculated to be attainable:

    Packet Size               Throughput
    (in bytes)          (pkts/sec)    (Kbps)
    -----------         ----------    ------
         64                   3000      1536
        100                   2900      2300
        200                   2250      3600
        400                   1156      3700
        800                    578      3700
       1024                    450      3700
       1518                    305      3700


To obtain these values, the hardware and software configurations must
be optimized; otherwise, yield will be lower.  For example, to forward
3.7 Mbps, at least three T-1 interfaces clocked at 1.536 Mbps are
required.

