Cisco CISCO1751 Quick Start Manual page 22

Configuring Voice-over-IP
Figure 18
Destination
To create a POTS dial peer for an FXS interface as explained earlier, you enter the complete telephone
number of the attached telephone as the destination pattern for incoming calls. However, to create a
POTS dial peer for an FXO interface, the destination pattern refers to outgoing calls, and you can include
wildcards in it because the PSTN performs the switching.
The VoIP feature can also remove digits that you do not want to send to the PSTN. For instance, to dial
9 to reach an outside line (that is, the analog PSTN), enter the following commands:
West> enable
Password:
West# configure terminal
West(config)# dial-peer voice 201 pots
West(config-dial-peer)# destination-pattern 9
West(config-dial-peer)# port 0/0
When you dial 9, the router makes a connection to the PSTN through voice port 0/0. The PSTN then
provides a dial tone, and any digits you enter on the telephone thereafter are interpreted on the PSTN.
To enable East router users to make calls over the West router local PSTN, enter the following
commands:
East(config)# dial-peer voice 701 voip
East(config-dial-peer)# destination-pattern 7
East(config-dial-peer)# session target ipv4:192.168.19.27
West(config)# dial-peer voice 601 pots
West(config-dial-peer)# destination-pattern 7
West(config-dial-peer)# port 0/0
When you dial 7 on the East router, the call is connected to the PSTN on the West router. The PSTN then
provides a dial tone, and any digits you enter on the telephone thereafter are interpreted on the PSTN.
Note In this example, West router voice port 0/0 has two separate POTS dial peers associated with it. Dial peer
201 matches calls beginning with the digit 9 and handles PSTN calls originating from the West router.
Dial peer 601 matches calls beginning with the digit 7 and handles calls to the PSTN originating from
the East router.
Cisco 1751 Voice-over-IP Quick Start Guide
22
FXO Gateway to PSTN
Source
dial-peer voice 201 pots
PSTN
cloud
FXS VIC
0/0
IP cloud
West
FXO VIC
1/0
destination-pattern 9
port 0/0
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