Black Box LGB2002A-R2 User manual

Connect 8, 16, or 24 twisted-pair devices
or segments together and to a fiber network.
Connect 8, 16, or 24 twisted-pair devices
or segments together and to a fiber network.
Back Office Switches
© 2008. All rights reserved. Black Box Corporation.
FREE 24-hour Tech Support: 724-746-5500
blackbox.com

2 of 6
1/4/2008
#26518
724-746-5500 blackbox.com
FEATURES
• Ideal for small or mid-sized office
networks.
• Port mirroring isolates network errors
while maintaining steady data flow.
• VLAN partitioning ensures optimum
network security and performance.
• Choose from three fiber uplink modules
to add distance to your network.
• Manage the switch via SNMP or the
Web.
When the Back Office Switches are configured in a port-based VLAN, the same VLAN members can’t be
located on different switches, every VLAN member can’t access all other VLAN members, and the switch
manager has to assign different names for each VLAN group at one switch.
When configured as an attribute-based VLAN, the same VLAN members can be at different Back Office
Switches with the same VLAN ID.
24-Port Back Office Switch
(LGB2003A)
VLAN1 VLAN2 VLAN3 VLAN4
VLAN1 VLAN2 VLAN3 VLAN4
16-Port Back Office Switch (LGB2002A)
with a Small Form Factor Pluggable
Optical Transceiver Installed
16-Port Back Office Switch (LGB2002A)
with a Small Form Factor Pluggable
Optical Transceiver Installed

3 of 6
1/4/2008
#26518
724-746-5500 blackbox.com
Link up to 8, 16, or 24 Ethernet, Fast Ethernet, or Gigabit
Ethernet devices to a twisted-pair network with BLACK BOX®
Back Office Switches.
The switches are perfect for small and mid-sized networks.
To cascade multiple switches, both models support up to eight
trunking groups. The LGB2008A links to up to four ports per
trunk, the LGB2002A supports up to eight ports per trunk,
and the LGB2003A handles up to 12 ports per trunk.
With port mirroring, data traveling to each switch port is
copied (or ”mirrored”) to a separate virtual port. The switch
uses these virtual ports to isolate network errors without
interrupting data flow.
Enhanced Quality of Service (QoS) ensures real-time
applications. QoS enables the switch to support the ToS field
of an IP header (equal DSCP low 3 bits) on Layer 3 of network
framework and six kinds of special transmission events on
Layer 4.
The switch also supports port-based VLAN and IEEE 802.1Q
Tag VLAN. VLAN configuration is used to partition a LAN into
smaller, more manageable LANs. With smaller LANs, security
and performance are maximized. Up to 16 VLANs can be
active, and VLAN IDs span from 1 to 4094.
Each twisted-pair device or segment can be located up
to 328 feet (100 m) from the switch. And if you want to take
advantage of fiber optic cable’s longer distance capability,
choose one of the Small Form Factor Pluggable (SFP) Optical
Transceivers. Three models are available: The LGB200C-MLC
works over multimode fiber optic cable and increases the
distance to 1804.4 feet (550 m). The LGB200C-SLC10 uses
single-mode fiber and supports distances up to 6.3 miles
(10.1 km). And the LGB200C-SLC30 works over single-mode
fiber optic cable and supports distances up to 18.9 miles
(30.4 km).
Connect 8, 16, or 24 10/100/1000 twisted-pair devices, 7, 15,
or 23 twisted-pair devices and one fiber module, or 6, 14, or
22 twisted-pair devices and two fiber links.
The switch meets common network standards, including
IEEE 802.3, 802.3u, 802.3ab, 802.3z, 802.3x and 802.3q.
Configure and manage the switch via its SNMP port or via
a Web connection.
Using the switch’s aggregation feature, you can bundle
more than one port with the same speed, full-duplex
operation, and the same MAC address into one logical port.
The single port’s resulting bandwidth is greater than that of
the ports linked separately.
OVERVIEW TECH SPECS
Distance (Maximum) — LGB2008A, LGB2002A–LGB2003A: 328 ft.
(100 m) over Category 5 or 5e unshielded twisted-pair cable;
LGB200C-MLC: Up to 1804.4 ft. (550 m) over 850-nm multimode fiber;
LGB200C-SLC10: Up to 6.3 mi. (10.1 km) over 1310-nm single-mode
fiber;
LGB200C-SLC30: Up to 18.9 mi. (30.4 km) over 1550-nm single-mode
fiber
Flow Control — IEEE 802.3x compliant for full-duplex, backpressure flow
control for half-duplex
Forwarding/Filtering Rate — 14,800 pps at 10 Mbps, 148,000 pps at
100 Mbps, 1,488,000 pps at 1000 Mbps
MAC Addresses — 8K, 4K VLAN table entries
Speed — LGB2008A, LGB2002A–LGB2003A: 10/100/1000 Mbps;
LGB200C-MLC, LGB200C-SLC10, LGB200C-SLC30: 1000 Mbps
Standards — IEEE 802.3, IEEE 802.3u, IEEE 802.3ab, IEEE 802.3z,
IEEE 802.3x, IEEE 802.3q
User Controls — Reset button
Connectors — LGB2008A: (8) 10-/100-/1000-Mbps twisted-pair RJ-45,
(2) Gigabit twisted-pair/SFP fiber slots for fiber modules,
(1) power connector;
LGB2002A: (16) 10-/100-/1000-Mbps twisted-pair RJ-45,
(2) Gigabit twisted-pair/SFP fiber slots for fiber modules,
(1) power connector;
LGB2003A: (24) 10-/100-/1000-Mbps twisted-pair RJ-45,
(2) Gigabit twisted-pair/SFP fiber slots for fiber modules,
(1) power connector;
LGB200C-MLC, LGB200C-SLC10, LGB200C-SLC30: (2) LC
Indicators — LGB2008A: (19) LEDs: (1) Power, (8) 10-/100-/1000-Mbps
twisted-pair ports 1–16, (8) Link/Act, (2) 1000-Mbps SFP fiber ports
15–16;
LGB2002A: (35) LEDs: (1) Power, (16) 10-/100-/1000-Mbps twisted-pair
ports 1–16, (16) Link/Act, (2) 1000-Mbps SFP fiber ports 15–16;
LGB2003A: (51) LEDs: (1) Power, (24) 10-/100-/1000-Mbps twisted-pair
ports 1–24, (24) Link/Act, (2) 1000-Mbps SFP fiber ports 23–24
Temperature Tolerance — 32 to 122° F (0 to 50° C)
Relative Humidity — Up to 90%, noncondensing
Power — 100–240 VAC, 50–60 Hz, autosensing
Size — LGB2008A: 1.75"H (1U) x 5.2"W x 8.5"D (4.4 x 13.2 x 21.7 cm);
LGB2002A–LGB2003A: 1.75"H (1U) x 17.4"W x 8.2"D
(4.3 x 44.2 x 20.8 cm)

4 of 6
1/4/2008
#26518
724-746-5500 blackbox.com
LGB2002A
Ethernet hubs vs. Ethernet switches.
Although hubs and switches look very similar and are
connected to the network in much the same way, there is a
significant difference in the way they function.
What is a hub?
An Ethernet hub is the basic building block of a twisted-
pair (10BASE-T or 100BASE-TX) Ethernet network. Hubs do
little more than act as a physical connection. They link PCs and
peripherals and enable them to communicate over a network.
All data coming into the hub travels to all stations connected
to the hub. Because a hub doesn’t use management or
addressing, it simply divides the 10- or 100-Mbps bandwidth
among users. If two stations are transferring high volumes of
data between them, the network performance of all stations
on that hub will suffer. Hubs are good choices for small- or
home-office networks, particularly if bandwidth concerns are
minimal.
What is a switch?
An Ethernet switch, on the other hand, provides a central
connection in an Ethernet network in which each connected
device has its own dedicated link with full bandwidth.
Switches divide LAN data into smaller, easier-to-manage
segments and send data only to the PCs it needs to reach.
They allot a full 10 or 100 Mbps to each user with addressing
and management features. As a result, every port on the
switch represents a dedicated 10- or 100-Mbps pathway.
Because users connected to a switch do not have to share
bandwidth, a switch offers relief from the network congestion
a shared hub can cause.
What to consider when selecting an Ethernet hub:
•Stackability. Select a stackable hub connected with a special
cable so you can start with one hub and add others as you
need more ports. The entire stack functions as one device.
•Manageability. Choose an SNMP-manageable hub if you
have a large, managed network.
What to consider when selecting an Ethernet switch:
•Manageability. Ethernet switches intended for large
managed networks feature built-in management, usually
SNMP.
•OSI Layer operation. Most Ethernet switches operate at
“Layer 2,” which is for the physical network addresses (MAC
addresses). Layer 3 switches use network addresses, and
incorporate routing functions to actively calculate the best
way to send a packet to its destination. Very advanced
Ethernet switches, often known as routing switches,
operate on OSI Layer 4 and route network traffic according
to the application.
Technically Speaking
The two most common Ethernet switch applications.
1. Segmenting LANs with multiple file servers:
Multiple users contending for multiple file servers can
wreak havoc on network efficiency. That’s because Ethernet
routes all data transmitted onto the network to every
attached device until it reaches its proper destination.
By segmenting your LAN with an Ethernet switch, you can
effectively reduce such bottlenecks by creating multiple wire-
speed pathways to key components, so your data moves as
fast as possible over the most direct route.
2. Adding high-speed workgroups:
You have a 10-Mbps LAN and you need to add a high-
speed workgroup, but you’re not yet ready to make the full
switch to 100 Mbps.
With an Ethernet switch, you can configure a dedicated
100-Mbps link and segment the remainder of your network—
boosting the performance capabilities of all attached devices!
Technically Speaking
•Modular construction. A modular switch enables you to
populate a chassis with modules of different speeds and
media types. Because you can easily change modules, the
modular switch is an adaptable solution for large, growing
networks.
•Stackability. Some Ethernet switches can be connected to
form a stack of two or more switches that functions as a
single network device. This enables you to start with fewer
ports and add them as your network grows.

5 of 6
1/4/2008
#26518
724-746-5500 blackbox.com
LGB2003A: front view
Gigabit Ethernet.
As workstations and servers migrated from ordinary
10-Mbps Ethernet to 100-Mbps speeds, it became clear that
even greater speeds were needed. Gigabit Ethernet was
developed for an even faster Ethernet standard to handle the
network traffic generated on the server and backbone level
by Fast Ethernet. Gigabit Ethernet delivers an incredible 1000
Mbps (or 1 Gbps), 100 times faster than 10BASE-T. At that
speed, Gigabit Ethernet can handle even the traffic generated
by campus network backbones. Plus it provides a smooth
upgrade path from 10-Mbps Ethernet and 100-Mbps Fast
Ethernet at a reasonable cost.
Compatibility
Gigabit Ethernet is a true Ethernet standard. Because it
uses the same frame formats and flow control as earlier
Ethernet versions, networks readily recognize it, and it’s
compatible with older Ethernet standards. Other high-speed
technologies (ATM, for instance) present compatibility
problems such as different frame formats or different
hardware requirements.
The primary difference between Gigabit Ethernet and
earlier implementations of Ethernet is that Gigabit Ethernet
almost always runs in full-duplex mode, rather than the half-
duplex mode commonly found in 10- and 100-Mbps Ethernet.
One significant feature of Gigabit Ethernet is the
improvement to the Carrier Sense Multiple Access with
Collision Detection (CSMA/CD) function. In half-duplex mode,
all Ethernet speeds use the CSMA/CD access method to resolve
contention for shared media. For Gigabit Ethernet, CSMA/CD
has been enhanced to maintain the 200-meter (656.1-ft.)
collision diameter.
Affordability and adaptability
You can incorporate Gigabit Ethernet into any standard
Ethernet network at a reasonable cost without having to
invest in additional training, cabling, management tools, or
end stations. Because Gigabit Ethernet blends so well with
your other Ethernet applications, you have the flexibility to
give each Ethernet segment exactly as much speed as it
needs—and if your needs change, Ethernet is easily adaptable
to new network requirements.
Gigabit Ethernet is the ideal high-speed technology to use
between 10-/100-Mbps Ethernet switches or for connection to
high-speed servers with the assurance of total compatibility
with your Ethernet network.
When Gigabit Ethernet first appeared, fiber was crucial to
Technically Speaking
running Gigabit Ethernet effectively. Since then, the
IEEE802.3ab standard for Gigabit over Category 5 cable has
been approved, enabling short stretches of Gigabit speed
over existing copper cable. Today, you have many choices
when implementing Gigabit Ethernet:
1000BASE-X
1000BASE-X refers collectively to the IEEE802.3z standards:
1000BASE-SX, 1000BASE-LX, and 1000BASE-CX.
1000BASE-SX: The “S“ in 1000BASE-SX stands for “short.“
It uses short wavelength lasers, operating in the 770- to 860-
nanometer range, to transmit data over multimode fiber. It’s
less expensive than 1000BASE-LX, but has a much shorter
range of 220 meters over typical 62.5-µm multimode cable.
1000BASE-LX: The “L“ stands for “long.“ It uses long
wavelength lasers operating in the wavelength range of 1270
to 1355 nanometers to transmit data over single-mode fiber
optic cable. 1000BASE-LX supports up to 550 meters over
multimode fiber or up to 10 kilometers over single-mode
fiber.
1000BASE-CX: The “C“ stands for “copper.“ It operates
over special twinax cable at distances of up to 25 meters. This
standard never really caught on.
Gigabit over CAT5—1000BASE-TX
The 802.3ab specification, or 1000BASE-TX, enables you to
run IEEE-compliant Gigabit Ethernet over copper twisted-pair
cable at distances of up to 100 meters of CAT5 or higher
cable.
Gigabit Ethernet uses all four twisted pairs within the
cable, unlike 10BASE-T and 100BASE-TX, which only use two
of the four pairs. It works by transmitting 250 Mbps over each
of the four pairs in 4-pair cable.

6 of 6
1/4/2008
#26518
724-746-5500 blackbox.com
Item Code
Back Office Switches
8-Port LGB2008A
16-Port LGB2002A-R2
24-Port LGB2003A-R2
Small Form Factor Pluggable (SFP) Optical Transceivers
Multimode, 850-nm, 550 m LGB200C-MLC
Single-Mode, 1310-nm, 10 km LGB200C-SLC10
Single-Mode, 1550-nm, 30 km LGB200C-SLC30
You might also need cable…
GigaBase®350 CAT5e 350-MHz Patch Cable,
4-Pair, Straight-Pinned, PVC, Beige,
s10-ft. (3-m) EVNSL85-0010
LGB2003A: rear view
Virtual LANs (VLANs).
True to their name, VLANs are literally “virtual“ LANs—
mini subLANs that, once configured, can exist and function
logically as single, secure network segments, even though
they may be part of a much larger physical LAN.
VLAN technology is ideal for enterprises with far-reaching
networks. Instead of having to make expensive, time-
consuming service calls, system administrators can configure or
reconfigure workstations easily or set up secure network
segments using simple point-and-click, drag-and-drop
management utilities. VLANs provide a way to define dynamic
new LAN pathways and create innovative virtual network
segments that can range far beyond the traditional limits of
geographically isolated workstation groups radiating from
centralized hubs.
For instance, using VLAN switches, you can establish a
secure VLAN made up of select devices located throughout
your enterprise (managers’ workstations, for example) or any
other device that you decide requires full access to the VLAN
you’ve created.
According to Cisco, a VLAN is a switched network logically
segmented by functions, project teams, or applications
regardless of the physical location of users. You can assign
each switch port to a different VLAN. Ports configured in the
same VLAN share broadcasts; ports that don’t belong to the
VLAN don’t share the data.
VLAN switches group users and ports logically across the
enterprise—they don’t impose physical constraints like in a
shared-hub architecture. In replacing shared hubs, VLAN
switches remove the physical barriers imposed by each wiring
closet.
To learn more about smart networking with VLANs, call
the experts in our Local Area Network Support group at
724-746-5500, press 1, 2, 4.
Technically Speaking
Recognize any of these situations?
• You wait more than 30 minutes to get through
to a vendor’s tech support.
• The so-called “tech” can’t help you or gives you
the wrong answer.
• You don’t have a purchase order number and the
tech refuses to help you.
• It’s 9 p. m. and you need help, but your vendor’s
tech support line is closed.
According to a survey by Data Communications
magazine, 90% of network managers surveyed say
that getting the technical support they need is extremely
important when choosing a vendor. But even though
network managers pay anywhere from 10 to 20% of their
overall purchase price for a basic service and support
contract, the technical support and service they receive
falls far short of their expectations—and certainly isn’t
worth what they paid.
At Black Box, we guarantee the best value and the
best support. You can even consult our Technical Support
Experts before you buy if you need help selecting just
the right component for your application.
Don’t waste time and money—call Black Box today.
Why Buy From Black Box?
Exceptional Value. Exceptional
Tech Support. Period.