Black Box LB9902A, LB9901A, LB9903A, LB9904A, LB9905A Specifications

Thermal design for use
in harsh environments
of uncontrolled heat
or cold.

Rugged steel cases act
as heat sinks.

100-Mbps switching
for high-performance
LANs.

Two fiber ports for
extended distances.

Autonegotiating on
six copper ports per

802.3u standard.

AC or DC power
options.

Daisychain units for
even greater distance.

Top-mounted LEDs for
easy monitoring.

Plug-and-play
installation.

E

thernet is increasingly being

used in ”out-of-the-way” and
industrial applications, whether
it’s for heavy manufacturing or
roadside traffic control.

But you want to be sure that
extreme temperatures and the
processes themselves won’t
adversely affect your network.
The BLACK BOX

®

Hardened
Ethernet Switches give you
the durability you require.

They’re designed specifically
for unheated and uncooled
applications, such as for use in
roadside control boxes, industrial
plants, mining and military sites,
or anywhere adverse weather or
industrial processes can wreak
havoc on your expensive circuitry.

Cased in 18-gauge steel,
the switches seal out bugs, dirt,
smoke, and other elements. The
plenum-rated switches come
packaged in a metal case and
hardware that serves as a heat sink
to draw heat away from the internal
electronics and dissipate it. To help
with this, each switch uses only
10 watts of power.

The switches can be used as
standalone units or mounted on a
metal shelf, pedestal, or wall.

Where the temperature can’t be

controlled, these industrial-strength

switches do the job.

Key Features

HARDENED ETHERNETSWITCHES

When used in the field, the
switches are typically fastened
to a metal pedestal or post planted
in the ground. This provides an
even larger heat sink to normalize
the operating temperature of the
internal electronics. Although
the switches’ packages aren’t
waterproof, they can be placed
in waterproof metal enclosures
to provide an all-weather
outdoor solution.

The ruggedness of the steel
case and temperature-control
packaging combined with the
high reliability of the design—more
than 10 years of MTBF!—make
for industrial-strength Ethernet
products.

The switches provide Fast
Ethernet switching on all ports.
All models have six 10-/100-Mbps
RJ-45 ports that autonegotiate
for speed and duplex mode. These
ports support twisted-pair copper
segment connections with 10- or
100-Mbps speed per the IEEE

802.2u standard.

For extended distance and
higher bandwidth through fiber
optic cabling, the switches
are available with a choice of
100-Mbps fiber port connectors

with multimode or single-mode
fiber connectors or a combination
of both. The fiber ports are set to
full-duplex mode. No media
converters are required.

The switches perform high­speed filter/forward operations on
the traffic to remove faulty packets
and minimize traffic congestion
while giving each port’s segment
a full 100 Mbps of bandwidth.

To achieve high performance,
each switch is non-blocking on all
ports and has 1-MB packet buffers
and a 16K-node address table for
advanced performance

And you’re given a choice
of power supplies: standard input
for autosensing AC power or DC
power. The latter is ideal for high
reliability and convenience in out­of-the-way locations. We even
offer an AC power supply as a
separate item, which you can use
as a backup to your primary AC
power input or apply it to the DC
model. Because the AC power
source is surge protected, it can
withstand lightning strikes. What’s
more, it features a military-style
screw-lock plug for secure
connections to the switch.

Black Box Corporation • 1000 Park Drive • Lawrence, PA 15055-1018 • Tech Support: 724-746-5500 • www.blackbox.com • e-mail: [e-mail]

© 2002. All rights reserved.

Black Box Corporation.

01/31/2002 #26073

• Hardened Ethernet Switch

• Power supply

• Power cord

• Users’ manual

Compliance: FCC Part 15 Class A;

UL

®

1950; CE; Bellcore GR-63­CORE Sections 4.4.1 and 4.4.3
(for shock and vibration)

Standards: 10BASE-T: IEEE 802.3;

100BASE-TX, -FX: IEEE 802.3u

Connectors: LB9901A, LB9904A:

(6) RJ-45 shielded 10/100;
(2) full-duplex multimode fiber
(1300-nm wavelength);

LB9902A, LB9905A:

(6) RJ-45 shielded 10/100;
(1) full-duplex multimode fiber
SC, (1) full-duplex single-mode
fiber (1300-nm wavelength);

LB9903A, LB9906A:

(6) RJ-45 shielded 10/100;
(2) full-duplex single-mode SC
(1300-nm wavelength)

Construction: 18-gauge steel case

Cooling Method: Convection, with

case operating as a heat sink

Filtering/Forwarding Rate:

From 100-Mbps ports:

Up to 148,800 pps;

From 10-Mbps ports:

Up to 14,880 pps

Latency: 10 to 100 Mbps or 100 to

10 Mbps: 5 µseconds

Mean Time Between Failure:

> 10 years

Indicators: (1) LED for power (PWR);

RJ-45 ports: (1) LED for speed,

link activity, transmitting and
receiving (LINK/ACT); (1) for
full- or half-duplex (F/H);

Fiber ports: (1) LED for link

activity

Speed: RJ-45 ports: 10 or 100 Mbps,

autonegotiating, half- or
full duplex;

Fiber ports: 100 Mbps, full duplex

Temperature Tolerance: -40 to

+160°F (-40 to +70°C); cold starts
as low as -4°F (-20°C)

Humidity Tolerance: 10 to 95%

noncondensing

DC Power Supply: 18–70 VDC,

autoranging

Size: 9"H x 5.8"W x 1.7"D (22.9 x

14.7 x 4.3 cm)

Weight: 3.5 lb. (1.6 kg)

AC Power Supply Specifications

Electrical Efficiency: 70% minimum

Input: 85–260 VAC, 47–63 Hz,

autoranging

Output: 5 VDC, up to 3 amps

Power Dissipation: 3 watts (typical)

Surge Protection: More than

150 joules

Surge Clamping: 800 volts, 50 amps

(minimum)

Overload and Short Circuit

Protection: Input fuse

Size: 1.5"H x 6.5"W x 6.5"D (3.8 x

16.5 x 16.5 cm)

Weight: 2 lb. (0.9 kg)

Package Includes:

Specifications

Technically Speaking

The Hardened Ethernet Switch
chassis houses one main PC board.
The front side of the chassis has six
RJ-45 twisted-pair ports and two
100-Mbps, full-duplex fiber ports,
which operate in full-duplex mode
only to provide higher bandwidth
and longer distances on fiber.

With the its six 10/100 RJ-45
switched ports, the switch has an
architecture that supports a dual­speed switching environment.
These copper ports, equipped
with autonegotiation capability,
operate in full or half-duplex and
sense for speed, per the IEEE 802.3u
standard.

Autonegotiation occurs when
an RJ-45 cable connection is made
on the copper ports and each time a
link is enabled. When the connected
device is 10 Mbps, the Hardened
Ethernet Switch obeys all the rules
of 10-Mbps Ethernet configurations.
10-Mbps users can share a
10-Mbps traffic domain and can
communicate with 100-Mbps users
as well as users in the 100-Mbps
domain. Similarly, 100-Mbps traffic
adheres to 100-Mbps Ethernet rules
and can communicate with the
10-Mbps domain, too.

The fiber optic ports are
switched ports and perform as a
domain, providing a high-bandwidth
backbone connection while
supporting longer distances, up
to 20 km (12.4 mi.) on models with
single-mode connections. You
can also daisychain the switches
in a string application to create an
Ethernet network that’s hundreds
of kilometers long.

You can connect the Hardened
Ethernet Switches to the following
three types of media: 100BASE-TX,
10BASE-T, and 100BASE-FX.

Packet filtering/forwarding.

Each time a packet arrives
on one of the switched ports, the
switch either filters or forwards it.

Packets with source and
destination addresses on the
same port segment are filtered
and constrained to one port so the
rest of the network doesn’t have to
process them. A packet that has a
destination address on another

port segment is forwarded to the
appropriate port. But packets that
you need for maintaining the
network’s operation—such as
occasional multicast packets—are
forwarded to all ports.

Frame buffering.

Because it’s a store-and­forward switch, each frame (or
packet) is loaded into the switch’s
memory and inspected before
forwarding can occur. This way,
all forwarded frames are of a valid
length and have the correct CRC.

By eliminating the propagation
of bad packets, all of the available
bandwidth can be used for valid
information during peak traffic
times.

The Hardened Ethernet
Switches dynamically allocate
buffer space from a 1-MB memory
pool to minimize the possibility of
dropping frames on congested
ports. This ensures that heavily used
ports receive very large buffer
space for packet storage. Allocation
of this sort enables the switch to
apply its resources to all traffic
loads, even when the traffic activity
is unbalanced across its ports.

Because network traffic
constantly varies in packet density

per port and in aggregate density,
the switch continually adapts
internally to provide maximum
network performance with the
least dropped packets.

Flow control.

Flow control kicks in when
the switch detects that its buffer
queue is losing space. It does this
by sending industry-standard (full­duplex only) ”pause” packets to the
devices sending packets, thereby
temporarily stopping incoming
traffic until existing traffic can catch
up without dropping packets. This
flow control process is transparent
to the user.

You also get a collision-based
flow-control mechanism. When
operating in at half-duplex, the
switch can prevent more frames
from entering a full buffer queue
by forcing a collision signal on all
receiving RJ-45 half-duplex ports.

The Hardened Ethernet Switch,
with an address table capacity of
16K node addresses, is suitable for
use in large networks. When nodes
are added or removed or moved
from one segment to another, the
self-learning switch automatically
keeps up with node locations. In
addition, its address-aging algorithm

causes least-used addresses to
drop out in favor of ones that you
use frequently.

Monitor activity via LEDs.

Plug-and-play, the Hardened
Ethernet Switch requires no
software configuration during
installation or for maintenance.

To monitor activity on the
switch, you simply view the LED
indicators on the unit’s top cover.
The LEDs conveniently indicate
operating status of all ports. There’s
a power ”on” (PWR) indicator, and
a self-test at power up. For each RJ­45, there are link/activity (LK/ACT)
LEDs indicating traffic and speed,
and full-/half-duplex indicators (F/H).
The fiber ports have link/activity
(LK/ACT) indicators.