Distinctive ring is used to identify internal and external incoming
calls. An internal call is defined as a call originating from any
Cisco Unified IP phone that is registered in Cisco Unified CME or is routed
through the local FXS port.
In Cisco CME 3.4 and earlier versions, the standard ring pattern is
generated for all calls to local SCCP endpoints. In Cisco Unified CME 4.0, the
following distinctive ring features are supported for SCCP endpoints:
Specify one of three ring patterns to be used for all types of
incoming calls to a particular directory number, on all phones on which the
directory number appears. If a phone is already in use, an incoming call is
presented as a call-waiting call and uses a distinctive call-waiting beep.
Specify whether the distinctive ring is used only if the incoming
called number matches the primary or secondary number defined for the
ephone-dn. If no secondary number is defined for the ephone-dn, the secondary
ring option has no effect.
Associate a feature ring pattern with a specific button on a phone
so that different phones that share the same directory number can use a
different ring style.
For local SIP endpoints, the type of ring sound requested is signaled to
the phone using an alert-info signal. If distinctive ringing is enabled,
Cisco Unified CME generates the alert-info for incoming calls from any phone
that is not registered in Cisco Unified CME, to the local endpoint. Alert-info
from an incoming leg can be relayed to an outgoing leg with the internally
generated alert-info taking precedence.
Cisco Unified IP phones use the standard Telcordia Technologies
distinctive ring types.