beautypg.com

Chapter 4: making network connections, Connecting network devices, Twisted-pair devices – Enterasys Networks V2H124-24P User Manual

Page 45: Power-over-ethernet connections, Chapter 4: making network connections 4-1, Power-over-ethernet connections 4-1

background image

4-1

Chapter 4: Making Network Connections

Connecting Network Devices

The Matix V-Series V2H124-24P switch is designed to be connected to 10 or
100 Mbps network cards in PCs and servers, as well as to other switches and hubs.
It may also be connected to remote devices using the optional 1000BASE-SFP
transceivers.

If 802.3af-compliant PoE devices are connected to the switch’s 10/100 Mbps ports,
the switch automatically supplies the required power.

Twisted-Pair Devices

Each device requires an unshielded twisted-pair (UTP) cable with RJ-45 connectors
at both ends. Use Category 5, 5e or 6 cable for 1000BASE-T connections, Category
5 or better for 100BASE-TX connections, and Category 3 or better for 10BASE-T
connections.

Power-over-Ethernet Connections

The Matrix V-Series V2H124-24P switch automatically detects an 802.3af-compliant
device by its authenticated PoE signature and senses its required load before
turning on DC power to the port. This detection mechanism prevents damage to
other network equipment that is not 802.3af complaint.

Note: Power-over-Ethernet connections work with all existing Category 3, 4, 5, 5e or 6

network cabling, including patch cables and patch-panels, outlets, and other
connecting hardware, without requiring modification.

The switch delivers power to a device using the two unused wire pairs in UTP or
STP cable (RJ-45 pins 4, 5, 7, and 8). The switch can provide up to 15.4 W of power
continuously on each 10/100 Mbps port. However, taking into account some power
loss over the cable run, the amount of power that can be delivered to a terminal
device is 12.95 W. If a device draws more than 15.4 W, from a port, an overload
condition occurs and the port turns off the power.

The switch controls the power and data on a port independently. Power can be
requested from a device that already has a data link to the switch. Also, the switch
can supply power to a device even if the port’s data connection has been disabled.
The power on a port is continuously monitored by the switch and it will be turned off
as soon as a device connection is removed.