Understanding the Cisco IP Phone Concepts and Registration - CCNA Voice 640-461 - page 50

Foundation Topics

Connecting and Powering Cisco IP Phones

Before we can get to the point of plugging in phones and having happy users placing and
receiving calls, we must first lay the foundational infrastructure of the network. This in-
cludes technologies such as Power over Ethernet (PoE), voice VLANs, and Dynamic Host
Configuration Protocol (DHCP). The network diagram shown in Figure 3-1 represents the
placement of these technologies. As you read this chapter, each section will act as a
building block to reach this goal. The first item that must be in place is power for the
Cisco IP Phones.

Fa0/0.10 (Voice VLAN) - 172.16.1.1
Fa0/0.50 (Data VLAN ) - 172.16.2.1

DHCP_VOICE
Range: 172.16.1.10 - 254
Mask: 255.255.255.0
Gateway: 172.16.1.1
Option 150: 172.16.1.1

DHCP_DATA
Range: 172.16.2.10 - 254
Mask: 255.255.255.0
Gateway: 172.16.2.1

PSTN

DHCP
Server

Fa0/0

Fa0/0
172.16.2.5/24
VL

V

WAN to Branch Offices

Skinny or
SIP Signaling

CME/CUE/
TFTP Server

VLAN 50

Internet

Fa0/20

Fa0/10

Fa0/24

V

SwitchA 802.1Q Trunk

Fa0/24

VTP Domain: VOICE

SwitchB Fa0/4

V

Fa0/3

802.3af Inline Power
802.1Q Tagging

Fa0/2

Fa0/1

RTP Audio

Voice VLAN 10

x2001 x2002 x2003 x2004

Data VLAN 50

Figure 3-1 VoIP Network

Cisco IP Phones connect to switches just like any other network device (such as PCs, IP-based
printers, and so on). Depending on the model of IP phone you are using, it may also have a
built-in switch. Figure 3-2 illustrates the connections on the back of a Cisco 7960 IP Phone.

The ports shown in Figure 3-2 are as follows:

RS232: Connects to a expansion module (such as a 7914, 7915, or 7916)

■

10/100 SW: Used to connect the IP phone to the network

■

10/100 PC: Used to connect a co-located PC (or other network device) to the IP Phone

■