Cisco 3725 Hardware Installation Guide - Page 29

Chapter 1 Overview of Cisco 3700 Series Routers Power Supply Options Power Supply Options Table 1-3 lists the power supply options supported by Cisco 3700 series routers. Depending on the configuration specified when you placed your order, your router may not support all of these options. Table 1-3 Power Supply Options for Cisco 3700 Series Routers Power Supply Option Cisco 3725 Cisco 3745 AC input power Yes Yes DC input power Yes Yes -48-V telephony power module to provide inline power to IP phones Yes Yes Dual hot-swappable power supplies No Yes1 Compatible with Cisco Redundant Power System Yes Yes 1. Because of increased power consumption in high-temperature environments, a fully loaded Cisco 3745 router requires both power supplies when ambient temperature exceeds 104°F (40°C). Cisco 3745 routers operating under these conditions do not support the online replacement of power supplies. Internal -48 V Telephony Power Modules Cisco 3700 series routers provide inline power to IP phones connected to the router through Ethernet switch network modules. This power is supplied by special -48 V modules that connect directly to the chassis power supplies in Cisco 3725 and Cisco 3745 routers. A single -48 V power module meets the power needs of up to 36 IP phones. A Cisco 3745 router with two -48 V power modules installed provides redundant power for up to 36 IP phones. Figure 1-5 and Figure 1-6 show the -48 -V power modules as they appear when installed in Cisco 3700 series routers. OL-2180-08 Cisco 3700 Series Routers Hardware Installation Guide 1-9