25
Cisco 1751 Voice-over-IP Quick Start Guide
78-11259-05
Configuring Voice-over-IP
Note
For these commands to take effect, you have to cycle the port by using the
shutdown
and
no shutdown
commands.
Note
Configure the PBX to pass all dual-tone multifrequency (DTMF) signals to the router.
Configure the
East
router similar to the
West
router. The
East
router connects to the PBX through an
E&M VIC port 0/1. Enter the following commands to configure a POTS dial peer for all
East
telephones:
East(config)#
dial-peer voice 211 pots
East(config-dial-peer)#
destination-pattern 1919555....
East(config-dial-peer)#
port 0/1
Enter the following commands to configure a VoIP dial peer for telephones on the
West
router:
East(config)#
dial-peer voice 221 voip
East(config-dial-peer)#
destination-pattern 1408555....
East(config-dial-peer)#
session target ipv4:192.168.19.27
East(config-dial-peer)#
exit
East(config)#
Enter the following commands to configure number expansion and to make it easy for
East
users to dial
numbers on the
West
router:
West(config)#
num-exp 5.... 1408555....
Finally, configure the E&M port:
East(config)#
voice-port 0/1
East(config-voice-port)#
signal immediate
East(config-voice-port)#
operation 4-wire
East(config-voice-port)#
type 2
Checking E&M Interface Configuration
If you configured the E&M interfaces correctly, you can place calls from a telephone served by one PBX
to a telephone served by the other PBX (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.
Note
Refer to the section
“Tuning Parameters for Real-Time Voice Traffic”
if you need to improve the quality
of voice connections.
Tuning Parameters for Real-Time Voice Traffic
Voice traffic is much more sensitive to timing variations than data traffic. For good voice performance,
you need to configure your data network so that voice packets are not lost or delayed. To achieve the
level of network performance needed for VoIP connections, use the following features to improve quality
of service (QoS):
•
IP precedence
•
Resource Reservation Protocol (RSVP)
