Technical Documentation

SRX210 Services Gateway PoE Overview

This topic includes the following sections:

Introduction

Power over Ethernet (PoE) is the implementation of the IEEE 802.3 AF and IEEE802.3 AT standards that allow both data and electric power to pass over a copper Ethernet LAN cable.

The SRX210 Services Gateway supports PoE on four ports, which supply electric power over the same ports that are used to connect network devices. PoE ports allow you to plug in devices that require both network connectivity and electric power, such as VoIP and IP phones and wireless access points.

You can configure the gateway to act as power sourcing equipment for devices connected on the designated ports.

Table 1 lists the SRX210 Services Gateway PoE specifications.

Table 1: SRX210 Services Gateway PoE Specifications

Power Management Schemes

Values

Supported standards

  • IEEE 802.3 AF (PoE)
  • IEEE802.3 AT (PoE+)
  • Legacy (pre-standards)

Supported ports

The following ports support PoE:

  • ge-0/0/0
  • ge-0/0/1
  • fe-0/0/2
  • fe-0/0/3

Total PoE power sourcing capacity

50 watts

Per-port power limit

30 watts

Power management modes

  • Static: power allocated for each interface can be configured
  • Class: power allocated for interfaces is decided based on the class of powered device connected

The IEEE 802.3 AF (PoE) functionality is supported on SRX210 Services Gateway PoE models that have power supply of 48V. The IEEE802.3 AT (PoE+) functionality is supported on SRX210 Services Gateway PoE models that have power supply of 54V. For more information, see Adjusting the Power Supply Adapter Tray for the SRX210 Services Gateway for Rack-Mount Installation.

  • The PoE+ functionality is available from JUNOS Software Release 10.2 or later.
  • The PoE+ functionality is available only if your gateway is using 54V power supply. You can order the 54V power supply from Juniper Networks. Contact your Juniper Networks customer service representative for more information.

PoE Classes and Power Ratings

A powered device is classified based on the maximum power that it draws across all input voltages and operational modes. When the class-based power management mode is configured on the services gateway, power is allocated by taking into account the maximum power ratings defined for the different classes of devices.

Table 2 lists the classes and their power ratings as specified by the IEEE 802.3 AF standard.

Table 2: PoE Classes and Power Ratings on the SRX210 Services Gateway

Class

Maximum Power Level Output from the PoE Port

0

15.4 watts

1

4.0 watts

2

7.0 watts

3

15.4 watts

4

30.0 watts

Related Topics

Published: 2010-05-26