Nortel BCM 3.7, Manual

Page: 425 / 1004

Determining analog settings 425
Programming Operations Guide
MWI tone/lamp matrix
The following table outlines the availability of MWI signals for analog telephones on Business
Communications Manager Systems.
ATA Dvc Modem
Telephon
Default: Modem
Devices connected to the system through an ATA can have connectivity issues over
BRI/PRI lines. To alleviate this, you can specify the type of device attached to the
analog line.
Modem supports 3.1 Khz audio, which requires a higher quality of service on the
ISDN trunks which modems and FAX machines require for reliable information
transfer. If the trunks cannot provide the higher level of service, the call will fail.
Telephon supports speech paths, which require less quality on the trunk; if used for
FAX and/or modem, information transfer would be unreliable.
Disconnect
Supervision
(GASM only) N
Y
Default: N
If you have a modem or fax machine that does not automatically disconnect when
the caller disconnects, you can set this field to Y and the system will disconnect the
line from the device once it receives the disconnect signal from the far end. This
feature is supported only by GASM modules.
Currently GASM supports Open Switch Interval (OSI) disconnect supervision.
When the system detects that the far end released a call, the current loop on the
GASM side is interrupted for a period of time (normally 850 ms). When the
connected analog device detects this signal, it restores itself to onhook (idle) state
to free the line.
Note: Some analog devices expect other types of disconnect signals, such as
reorder or busy tone.
For this feature to work, the trunk must be set to Supervised/Loop Guarded. Refer
to
“Loop start analog/digital fields” on page 249 .
Tips:
If you have a modem or fax machine, keep the ATA answer timer delay short. If a
call to a fax machine or modem cannot connect, shorten the delay. If an individual dials
the number for a fax machine or modem, make the delay a little longer.
Table 84 Availability of MWI signals
ATA2 Norstar ASM via FEM Norstar ASM-MW via FEM ASM GASM
Systems running software versions previous to BCM 3.6
MWI tone No No NA only No NA only
MWI lamp No No NA only No NA only
Systems running BCM 3.6 or newer software
MWI tone Yes Yes Yes Yes Yes
MWI lamp No No NA only No Yes
NA = North America
Table 83 ATA settings (Continued)
Attribute Values Description