3Com 3CNJPSE24 - Manual (Page 11)

Introduction to the Ethernet Power Supply
Ethernet Power Supply User s Guide 1-3
Ethernet Power Supply Front View Detail
Figure 1 Ethernet Power Supply Front View
10/100BASE-TX Data & Power Output Ports, Upper 24 Ports
The Ethernet Power Supply has 24 Data & Power ports
configured as Media Dependent Interface (MDI) non-crossover.
These ports are designed to carry Ethernet data over the
standard 2-wire pairs (RJ-45 pins 1/2 and 3/6) and DC power
source over the spare wire pair (RJ-45 pins 4/5 and 7/8).
10/100BASE-TX Data Input Ports, Lower 24 Ports
The Ethernet Power Supply has 24 10BASE-T/100BASE-TX-
data input ports, configured as MDI non-crossover. These ports
are designed to carry Ethernet Data only (TX/RX) over the
standard 2-wire pairs (RJ-45 pins 1/2 and 3/6).
According to the IEEE 802.3 standard, the maximum allowable
distance between two Ethernet links is 100m (328ft). The
Ethernet Power Supply meets this IEEE 802.3 requirement.