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3C16440
SuperStack II Baseline Hub
103,389
1,779,785
12 port
(203 years)
3C16441
SuperStack II Baseline Hub
97,425
1,368,075
24 port
(156 years)
3C16592A
SuperStack II Baseline Dual Speed Hub
55,816
459,360
12 port
(52 years)
3C16593A
SuperStack II Baseline Dual Speed Hub
44,949
307,563
24 port
(35 years)
3C16460
SuperStack II Baseline Switch
76,820
507,012
12 port 10 Mbps switched ports plus
(57 years)
2 x 10/100 Mbps auto-sensing ports
3C16462
SuperStack II Baseline Switch
73,491
625,408
24 port 10 Mbps switched ports plus
(71 years)
2 x 10/100 Mbps auto-sensing ports
3C16464A
SuperStack II Baseline 10/100 Switch
82,963
760,096
12 port
(87 years)
3C16465A
SuperStack II Baseline 10/100 Switch
67,662
645,753
24 port
(74 years)
Theoretical
MTBF (hours)
Actualized
Most links between network devices
run in half-duplex mode. This is the
traditional mode of Ethernet opera-
tion allowing communication across
the cabling in one direction at any
particular time. Full-duplex mode
allows simultaneous bidirectional
traffic. It effectively doubles the
throughput across UTP cable to
20 Mbps for Ethernet and 200 Mbps
for Fast Ethernet.
Full-duplex communication can only
be sustained between two switches,
or between a switch and a network
end-station (such as a PC or server).
Hubs (Ethernet or Fast Ethernet)
are not able to support full-duplex
network links according to ISO/IEEE
standards.
Full-duplex autonegotiation is
the process where the network
devices at either end of the cable
(for example a switch and a server)
automatically decide whether they
will communicate in either full- or
half-duplex mode. It will happen
almost instantaneously when the
UTP cable is connected and the link
is first made.
Full-duplex operation is especially
effective for relieving bottlenecks
that might exist in a network,
for example, on a link between two
switches or on a link from a switch
to a network server.
All SuperStack II Baseline Switches
support full-duplex autonegotiation
on every port, so you can be sure
you get the ultimate capacity from
your installed equipment.
Full-duplex autonegotiation
MDI/MDIX Switch
The MDI/MDIX switch on the
front panel of 3Com’s SuperStack II
Baseline products lets you build
your entire network using standard
UTP cabling. By using the MDI/MDIX
switch, your hubs and switches are
cascaded together without the need
to use special crossover cable.
Reliability
3Com Baseline products have been
designed with reliability in mind.
You can be assured they will give
you troublefree operation. 3Com uses
advanced HALT (Highly Accelerated
Life Test) techniques at the design-
phase to stress-test our products
far beyond any normal operating
conditions. We can identify and
design-out even the most minimal
contributors to unit failure.
This is reflected in the reliability
figures for each of the SuperStack II
Baseline products, as shown in the
table. Reliability is expressed as a
Mean Time Before Failure (MTBF)
in hours, and calculated according
to an established industry standard
(MIL-HBK 217 F Notice 1). Because
the theoretical calculation has proved to
be extremely conservative, we also quote
an actualized figure. This is derived
from the in-service reliability track
record of the tremendous installed-base
of 3Com SuperStack II products.
The table shows that for simpler
technology such as hubs, the MTBF
is far greater than on more complex
products such as dual-speed hubs.
Even so, with a worst-case MTBF
of 35 years, the SuperStack II Baseline
products have built-in reliability found
in no other brand.
Warranty
For complete peace-of-mind, all 3Com
SuperStack II Baseline products come
with a lifetime limited warranty.
As part of this we provide you with
an advanced hardware exchange
service for the first year from your
date of purchase, in accordance with
3Com’s standard terms and conditions.
To qualify, you must complete and
return your product registration card
to 3Com. Consult your user guide for
full details.
SuperStack II Power Systems
1. Advanced Redundant Power System
For the ultimate protection
against network downtime, all
SuperStack II Baseline products
are equipped with a connector to
support the SuperStack II advanced
Redundant Power System (ARPS).
This system gives you the means
to provide SuperStack II units
with a redundant power supply
source for uninterrupted operation
in the unlikely event of a power
supply failure.
2. Uninterruptible Power System
The SuperStack II Uninterruptible
Power System (UPS) keeps your
system up and running during power
failures or disruption to the main
supply. Up to four SuperStack II
units can be powered from a single
UPS. The system also protects you
against brownouts or spikes that
occur in outside power lines.
