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Checking the Remote Dial Peer Configuration

If you configured VoIP dial peers on your router by following these examples, you can place calls from that router to telephones
on the remote routers (using just the extension if you configured number expansion). If you have trouble placing calls, ping the
remote router to make sure you have IP connectivity, or use the show dial-peer voice command to verify that the data you
configured is correct.
Note See the “Configuring Quality of Service” section on page 31 if you need to improve the quality of voice connections.
Configuring FXO Interfaces
FXO interfaces provide a gateway from the VoIP network to the analog PSTN or to a PBX that does not support E&M signaling
so that users can reach telephones and fax machines outside the VoIP network. Figure 19 shows a typical FXO gateway attached
to the West router.
Figure19 FXO Gateway to PSTN
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 1/0
When you dial 9, the router makes a connection to the PSTN through voice port 1/0. The PSTN then provides a dial tone. 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 1/0
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.
West IP cloud
PSTN
cloud
51077
FXO VIC
1/0
FXS VIC
0/0
Source
Destination
dial-peer voice 201 pots
destination-pattern 9
port 0/0