Power over Ethernet Overview
Installing and Managing Power over Ethernet (PoE)
page 3-4
OmniSwitch 7700/7800 Hardware Users Guide
April 2005
Power over Ethernet Overview
Power over Ethernet Application Example
The diagram above shows the power path from a conventional power source—e.g., an Uninterruptible
Power Source (UPS)—to attached powered devices (PDs) located in a separate area of the building or
campus. PDs include IP telephones and wireless LAN devices.
Important.
Alcatel recommends that PoE-enabled switches with attached IP telephones should have oper-
ational power supply redundancy at all times for 911 emergency requirements. In addition, both the chas-
sis and the power shelf should be plugged into an Uninterruptible Power Source (UPS).
The items listed below (1–5) describe the major components and connections in the application example.
Refer to the corresponding numbers (1–5) in the diagram above for specific locations of these major
components and connections.
1
The power supplies in the OS7800 chassis are plugged into an AC power source located in the
Building One data center. These power supplies provide power for basic switch operations.
2
Also in the Building One data center, an OS7-IP-SHELF is attached to the OS7800 via DB-25
chassis-to-power-shelf cables. (Connections for the chassis-to-power-shelf cables are located on the rear
panel of the switch chassis, as well as the rear panel of the separate OS7-IP-SHELF.)
1x
3x
5x
7x
9x
11
x
13x
15x
17x
19x
21x
23x
OK1
OK2
24x
2x
IP Telephones
Chassis-to-Power-Shelf Cables
Connections to AC Power Source
IP Telephones
Ethernet Cables
UPS or Other Valid
Power Source
OmniSwitch 7800
Power Shelf
1
2
4
3
(No additional AC power source
required for attached PDs.)
Wireless LAN Devices
UPS or Other Valid
Power Source
5
5
