HP procurve J8164A - Manual (Page 8)

Introduction
Overview
Power Over Ethernet connections to embedded computers will allow much
cheaper installation (no AC cabling, lower labor costs), facilitate updating the
installation and repositioning of sensors without electricians, while main­
taining full control over every node through the Internet, with VoIP and
webcam telephony. Functionality can be changed by downloading new soft-
ware through the network.
Figure 1 shows a typical system implemented to power telephones. The PoE
Ethernet switches are installed to supply power over the twisted pair LAN
cables to run phones or other appliances as required. In
tr
odu
ctio
n
HP PoE switch HP PoE switch
Mitel 3300 IP PBX
5300xl
Figure 1-1. Example of a Typical Implementation
Here are some reasons why you might want to do this:
■ Only one set of wires to bring to your appliance - simplifies installation
and saves space.
■ There is no need to pay for additional electrical power runs or to delay
your installation schedule to make them- saves time and money.
■ The appliance can be easily moved, to wherever you can lay a LAN cable
- minimal disruption to the workplace.
■ Safer - no AC voltages need to be added for additional network devices.
■ As well as the data transfer to and from the appliance, you can use SNMP
network management infrastructure to monitor and control the
appliances.
■ Appliances can be shut down or reset remotely - no need for a reset button
or power switch.
■ When implementing wireless LAN systems it simplifies the RF survey task,
as the access point can easily be moved and wired in.
1-2