Powering Ip Telephones - Avaya Application Solutions Deployment Manual

Powering IP Telephones

The Avaya 4600 Series IP Telephones were designed to use flexible powering methods. Some
of these powering solutions require the use of special cables that are designed specifically for
the Avaya 4600 Series telephones.
The following subsections are discussed:
Background
Types of IP Telephone power
Configuring the IP Telephones for power
Background
To meet the critical needs of the business, two generations, Gen-1 and Gen-2, of the 4606,
4612, and 4624 IP Telephones were developed. The second-generation IP Telephones, Gen-2,
added Power over Ethernet (PoE) to the capabilities of the original IP Telephone. Either local or
centralized power can be provided to the IP Telephones (4606, 4612, and 4624 models only) by
one of the following four methods:
Power over Spare Pairs pins 4/5 (GRD) and 7/8 (-48 volts) of an RJ45 connector
Power over Data/Signal Pairs pins 1/2 (-48 volts) and 3/6 (GRD) of an RJ45 connector
Power over, Traditionally, pins 7 (-48 volts) and 8 (GRD) of an RJ45 connector
Power through the barrel connector on the bottom of the telephone
Types of IP Telephone power
Centralized power
IEEE, the standards body that governs PoE, has not ratified a final position on PoE. However, a
working draft (Rev.3.0) of IEEE 802.3af has been in place to establish guidelines for this area
since November 2001, and was updated to Rev.3.2 in September, 2002. With PoE,
(IEEE Draft 802.3af standard), both power and data are carried over one CAT 5 Ethernet cable.
Deploying the IP Telephones using PoE eliminates the need for a local power supply, AC
adapter, and cables. Thus, power can be provided from the wiring closet or the switch room,
where it can be easily connected to a UPS system.
The key technical characteristics of the IEEE Draft 802.3af standard for PoE are:
Power Sourcing Equipment (PSE) output voltage is 44 VDC to 57 VDC.
Power Sourcing Equipment (PSE) output current is 350 mA, maximum.
Power Sourcing Equipment (PSE) power is 15.4 watts, maximum.
Powered Device (PD) power draw allowed is 12.95 watts, maximum.
IP terminals deployment
Issue 3.4.1 June 2005 299