Specifications

CHAPTER
7-1
Cisco IGX 8400 Series Provisioning Guide, Release 9.3.3 and Later Releases
OL-1166-04
7
Cisco IGX 8400 Series Voice Service
Voice Service—Functional Overview
The IGX supports voice connections through installation and configuration of the following
voice-service modules:
• Universal voice module (UVM—see the “Universal Voice Module” section on page 2-36)
• Channelized voice module (CVM—see the “Channelized Voice Module” section on page 2-44)
• Universal router module (URM—see the “Universal Router Module” section on page 2-84)
Signaling
Signaling allows a phone or other device to communicate with the network and destination device in
order to set up and tear down a call and provide other necessary functions.
Signaling techniques are categorized as either supervision, addressing, or alerting. A call cannot take
place without all of these signaling techniques.
• Supervision signaling involves detecting changes to the status of a loop or trunk and, in response,
generating a predetermined response such as closing a circuit (loop) to connect a call.
• Addressing signaling involves passing dialed digits to a private branch exchange (PBX), central
office (CO), or other switching device, which then sets up a path between calling and called party.
• Alerting signaling provides audible tones such as dial tone, ringing, number dialing, busy signal,
and off-hook notification to the user.
Signaling can be in-band (carried on the same circuit as the data path) or, more commonly now,
out-of-band (carried on a separate circuit).
Switching
Switching involves connecting a calling party or device to a called party or device. A switch examines
incoming data, determines their destination, and sets up a transmission path through its switching matrix
to connect the incoming port to the appropriate outgoing port.