Mitel 6800 Series, Administrator'S Manual, Page: 390 / 1113

Mitel 6800 Series SIP Phone Release 4.2.0 SP2 Administrator Guide
5-127
contact, copy a contact from an external source directory or list, and assign individual contact
ring tones, refer to your
Mitel Model-Specific SIP Phone User Guide
.
NO SERVICE CONGESTION TONE
Administrators can configure the IP phones to play a congestion/fast busy tone instead of a
dial tone when the phone is in a “No Service” state. This feature allows visually impaired persons
the ability to discern whether or not the phone is in service and can be used to send/receive calls.
The configuration parameter “
no service congestion tone
” allows administrators the ability
to enable this accessibility feature. When enabled, the congestion tone will replace the
conventional dial tone when the handset is off hook, a headset is employed, or the
speakerphone is engaged. The congestion tone’s frequency/pattern is based on the respective
phone’s configured tone set. Additionally, the congestion tone is played on a per-line basis
whereby only the specific lines that are without service are affected.
With consideration to scenarios where a dial tone should be played even if the phone is in a
“No Service” state (e.g. scenarios where the proxy may still accept INVITEs from the phone
even if unregistered), the “
no service congestion tone
” parameter has been programmed as
disabled by default.
CONFIGURING THE NO SERVICE CONGESTION TONE
Use the following procedures to configure the no service congestion tone feature.
For specific parameters you can set in the configuration files, see Appendix A, the section,
“No
Service Congestion Tone Settings”
on
page A-179
.
PRIORITY ALERTING
Priority alerting on the IP phones is a feature that allows incoming calls to trigger pre-defined
ringing or call waiting alert tones.
You can enable or disable priority alerting on the IP phone for the Asterisk, BroadWorks, and
Sylantro servers using the configuration files and the Mitel Web UI. Configuration of priority
alerting is on a global-basis only.
HOW PRIORITY ALERTING WORKS
When the IP phone detects an incoming call, the phone firmware inspects the INVITE request
in the IP packet for an "Alert-Info" header.
If it contains an "Alert-Info" header, the firmware strips out the URL and keyword parameter
and maps it to the appropriate Bellcore tone.
Note:
If the phone or individual lines are configured to have no registration by intent
(e.g. if the Registrar is set to 0.0.0.0) enabling the “
no service congestion tone
”
parameter will have no effect and the default dial tone will be played.
CONFIGURATION FILES