Chapter 6
| Port Connections
Power-over-Ethernet Guidelines
– 33 –
1000BASE-T Cable Requirements
All Category 5 UTP cables that are used for 100BASE-TX connections should also
work for 1000BASE-T, providing that all four wire pairs are connected. However, it is
recommended that for all critical connections, or any new cable installations,
Category 5e (enhanced Category 5) or Category 6 cable should be used. The
Category 5e and 6 specifications include test parameters that are only
recommendations for Category 5. Therefore, the first step in preparing existing
Category 5 cabling for running 1000BASE-T is a simple test of the cable installation
to be sure that it complies with the IEEE 802.3-2008 standards.
Power-over-Ethernet Guidelines
The switch supports both IEEE 802.3af and IEEE 802.3at-2009 PoE standards that
enable DC power to be supplied from the switch’s RJ-45 copper ports to connected
devices by utilizing certain wire pairs in the connecting Ethernet cable.
The total PoE power delivered by all ports cannot exceed the 390 W switch power
budget. This means that up to 12 ports can supply a maximum 30 W of power
simultaneously to connected devices, or all 24 ports can supply a maximum of
15.4 W simultaneously. For each attached PoE-compliant device, the switch
automatically senses the load and dynamically supplies the required power.
Any PoE-compliant device attached to a port can directly draw power from the
switch over the Ethernet cable without requiring its own separate power source.
This capability gives network administrators centralized power control for devices
Table 10: 1000BASE-T MDI and MDI-X Port Pinouts
Pin
MDI Signal Name
MDI-X Signal Name
1
Bi-directional Pair A Plus (BI_DA+)
-52V power (Negative V
port
)
Bi-directional Pair B Plus (BI_DB+)
GND (Positive V
port
)
2
Bi-directional Pair A Minus (BI_DA-)
-52V power (Negative V
port
)
Bi-directional Pair B Minus (BI_DB-)
GND (Positive V
port
)
3
Bi-directional Pair B Plus (BI_DB+)
GND (Positive V
port
)
Bi-directional Pair A Plus (BI_DA+)
-52V power (Negative V
port
)
4
Bi-directional Pair C Plus (BI_DC+)
-52V power (Negative V
port
)
Bi-directional Pair D Plus (BI_DD+)
GND (Positive V
port
)
5
Bi-directional Pair C Minus (BI_DC-)
-52V power (Negative V
port
)
Bi-directional Pair D Minus (BI_DD-)
GND (Positive V
port
)
6
Bi-directional Pair B Minus (BI_DB-)
GND (Positive V
port
)
Bi-directional Pair A Minus (BI_DA-)
-52V power (Negative V
port
)
7
Bi-directional Pair D Plus (BI_DD+)
GND (Positive V
port
)
Bi-directional Pair C Plus (BI_DC+)
-52V power (Negative V
port
)
8
Bi-directional Pair D Minus (BI_DD-)
GND (Positive V
port
)
Bi-directional Pair C Minus (BI_DC-)
-52V power (Negative V
port
)