Black Box Mixed-Media Fiber Hubs
Installation and User Guide (4/99)
time. In a stacked configuration, the complete stack operates as one logical dual-speed repeater.
Depending upon the stack configuration (one LH8050 and up to two LH8016A-C units), up to
48 front Ethernet segments with a mix of fiber and copper ports is supported.
The LH8050A is compact in design at only 1.75 in. (4.4 cm) high, and has a
lightweight metal enclosure. It is easily rack mounted in a standard 19" rack and typically
operates in a rack as the departmental hub for a multiple-backbone Ethernet network.
2.3.1
The Black Box Fiber Hub Chassis
The LH8050A chassis houses one main PC board and an internal bridge module
(daughter board). There are 16 front slots for mixed-media modules. Each front slot in the dual-
speed chassis can accept any LH8050A Port Module (PM) which will provide either 10 or
100Mbps operation over either fiber or twisted pair cabling. The LH8050A is configured by
selecting individual PMs, one per Ethernet port to be used. Configured LH8050A units provide
two traffic domains, one each with IEEE 802.3 and 802.3u repeater functionality.
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Figure 2.3.a: LH8050A, Front View
LEDs to indicate operating status are on the left front side. There are power (PWR)
and bridge-inside (BR) indicators for the unit. There
are collision (COL) indicators for each of the 10
Mbps and 100Mbps domains for visual indication of
the operating status of each domain, and two activity
(ACT) indicators for traffic activity on each domain.
These LEDs provide a visual assessment of the
operational condition and aggregate network activity
of all segments installed in the unit.
Figure 2.3.b: Front Panel LEDs
AC Power Connector:
On the right side rear of the unit is the connection to the
auto-ranging internal power supply that automatically adapts to the AC voltage of the AC
power system into which it is being installed. An ON/OFF power switch is used for powering
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PWR BRD
ACT
COL
Black Box LH8050A
Mixed Media Fiber Hub
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R L S
R L S
R L S
R L S
R L
R L
R L
R L
R L
R L
R L
R L
R L
R L
R L
R L
ACT
COL
PWR BRD
Black Box LH8050A
Mixed-Media Fiber Hub
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