Avaya Communication Manager Administrator's Manual page 1739

When the CAMA feature is administered and a 911 call is placed from an Avaya Communication
Manager station, Communication Manager searches for the proper CAMA Touch-Tone Receiver (TTR)
resource in the port network (PN) where the CAMA trunk group is located. If the proper CAMA TTR
resource is not available in that port network, the software checks any other available port networks for
the CAMA TTR. If none is found in the entire system, a busy tone is returned to the calling party.
However, if another trunk group is in the same routing pattern as the CAMA trunk group, the call routes
to the next available trunk group in the pattern. For example, if a CO trunk group is used, then any
available TTR resource can be used and the call routes as a normal call over the CO trunk and the public
switched telephone network (PSTN).
E911 systems use CESID information to identify the location of the calling phone. The following features
can cause incorrect CESID information to be sent with a 911 call.
Bridged stations
911 calls from a bridged extension will report the CESID of the principle station.
EAS agents
911 calls from an agent in an EAS skill will report the CESID of the physical station, not the logical
agent.
Personal Station Access/Terminal Translation Initialization
When you use PSA or TTI to associate a phone with another extension, Communication Manager will
report the CESID of the extension — not the physical phone associated with it.
CO — Central Office
CO trunks transmit dialed digits for outgoing calls but not for incoming calls. Use CO trunks when you
want all incoming calls go to the same destination, such as an attendant or a voice menu system.
Individual users can place outgoing calls without attendant assistance. CO trunks typically connect your
media server or switch to the local central office, but they can also connect adjuncts such as external
paging systems and data modules.
CPE — Customer-Provided Equipment
Use CPE trunks to connect adjuncts, such as paging systems and announcement or music sources, to the
server running Communication Manager.
NOTE:
You can connect some types of equipment to Communication Manager by trunks without
administering a CPE trunk group. For example, trunk port interfaces can be assigned on
system screens for Music-on-Hold Access
voice and chime paging
DID — Direct Inward Dialing
DID trunks carry incoming calls directly from the local central office to your server running
Communication Manager. These trunks transmit the digits Communication Manager needs to route
incoming calls to specific extensions. Use DID trunks when you want people calling your organization to
dial individual users directly without going through an attendant or some other central point.
Administrator's Guide for Avaya Communication Manager
November 2003
(Feature-Related System Parameters
(Loudspeaker Paging and code calling access screen).
Feature Reference
Trunks and trunk groups
screen) or
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