Technical Documentation

SRX 210 Services Gateway PoE Overview

This section includes the following topics:

Introduction

Power over Ethernet (PoE) is the implementation of the IEEE 802.3 AF standard, allowing both data and electric power to pass over a copper Ethernet LAN cable.

The SRX 210 services gateway provides four PoE 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 phones, wireless access points, and IP phones.

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

Table 1 lists the SRX 210 services gateway PoE specifications.

Table 1: SRX 210 Services Gateway PoE Specifications

Power Management Schemes

Values

Supported standards

  • IEEE 802.3 AF
  • Legacy (pre-standards)

Supported ports

PoE is supported on the following four ports:

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

Total PoE power sourcing capacity

50 watts

Per port power limit

15.4 watts

Power management modes

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

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 Class-based power management mode is configured on the gateway, power is allocated 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 SRX 210 Services Gateway

Class

Usage

Maximum Power Levels Output from PoE Port

0

Default

15.4 Watts

1

Optional

4.0 Watts

2

Optional

7.0 Watts

3

Optional

15.4 Watts

4

Reserved

All class-4 powered devices are treated as class 0.