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Feature Reference
Call coverage
Administrator’s Guide for Avaya Communication Manager 1425
November 2003
Off-Net Call Coverage
Call Coverage allows a call to be redirected to a destination on the public network. The remote (off-net)
number is administered on the Remote Call Coverage Table screen and may have up to 16 digits
including either the outgoing trunk access code (TAC) or the FAC specifying ARS or AAR. Any
coverage point can be an off-net destination.
Whenever an incoming trunk call is redirected off-net (coverage or forwarded), a timer is set that
precludes any other incoming trunk call from redirecting off-net until the timer either expires or is
cancelled. The rationale for this mechanism is to prevent calls that were redirected off-net from being
re-routed back to the original principal from the off-net destination, effectively creating a round-robin
loop that continuously seizes trunks until they are exhausted.
Communication Manager provides the means of performing call classification on an off-net coverage call
to determine its disposition. If the off-net call is carried completely over ISDN facilities to its final
destination, then ISDN trunk signaling is used to monitor the call. Otherwise, the system uses a call
classifier port.
When Communication Manager tries to classify an off-net coverage call (CCRON) using a call classifier
port, the system introduces an unavoidable cut-through delay while the call classifier port attempts to
identify an answered call. Neither the originating nor the answering party can hear each other during this
delay of up to 1 second. A call classifier is attached to all off-net coverage calls made over analog
facilities and also over ISDN facilities if the call is interworked to non-ISDN facilities on the public
network.
When the Coverage of Calls Redirected Off-Net Enabled field on the System-Parameters
Coverage-Forwarding screen is y:
•
The system monitors off-net calls (call classification) and brings them back to the switch if they
are not answered within the defined time interval. (Set this interval in the
Off-Net Cvg
Subsequent Redirection/CFWD No Ans Interval
field on the System-Parameters
Coverage-Forwarding screen.) Calls also return to the switch if the system detects a call progress
tone, such as busy or reorder.
•
A simulated bridge appearance (SBA) is put on the principal and the green lamp is put in flashing
mode; the principal can pick up the call at any time. You have the option of dispensing with call
classification (and consequently the SBA) on a final CCRON coverage point.
•
When a call classifier port is used to classify the call, the switch plays local ringback tone to the
caller while the off-net call is being classified, concealing from the caller what is happening on
the public network. When the call is answered off-net, it is likely that the first few syllables
spoken by the answering party will not be heard by the calling party.
•
If any party on the call is on HOLD when the call routes off net, the call classifier is removed
from the call. The call behaves in the same manner as off-net calls when the Coverage of Calls
Redirected Off-Net field is
n
.
•
While an off-net call is undergoing call classification, any party who is not already on the call will
be unable to bridge onto the call. Also, the originating party cannot release the call, conference
anyone else onto the call, or transfer the call to a new party. Once the call is answered off-net or
the call is returned to the switch for further call processing, then these restrictions are removed.
•
If the last point in a coverage path is an off-net destination and no trunks are available to route the
call, the switch attempts to re-terminate the call to the principal.