Instruction manual

Page 1478 of 3156 FCC Compliance for DID Answer Supervision
553-3001-306 Standard 10.00 January 2002
This feature is designed specifically for telephone calls coming in through
Direct Inward Dialing (DID) trunks. Answer supervision for all other types
of telephone calls is not affected. This feature works in conjunction with the
following types of calls:
• Direct Inward Dialing (DID) calls terminating at the Meridian 1 and
forwarded to a Recorded Announcement (RAN).
• Direct Inward Dialing (DID) calls forwarded by the system through the
public switched network (PSN) to another number in the Public
Exchange/Central Office (CO), or to another Meridian 1.
On North American COT, FEX, and WATS trunks, Central Offices do
not always return answer supervision. When no answer supervision is
returned, the Meridian 1 software uses the end-of-dial timer for non-
Digitone trunks (EOD timer), or the end-of-dial timer for Digitone trunks
(ODT timer) to verify call connection. For Federal Communications
Commission (FCC) compliance, the EOD and ODT timers will still be
used for incoming DID calls, except that EOD is capped at 20 seconds
even if configured for more.
This feature handles incoming DID calls over Data Terminal Interface (DTI),
Integrated Services Digital Network (ISDN), and analog trunks. Outgoing
calls over Central Office (CO) and TIE trunks are also handled. System
components involved include trunks, the Meridian 1, and the CO.
The following explains how the system components handle answer
supervision.
• Analog, DTI, and ISDN incoming trunks: These are covered as long as
they are DID incoming trunks. For incoming analog and DTI trunks,
answer supervision or pseudo-answer supervision is returned by the
Meridian 1 to the CO, if necessary. For incoming ISDN trunks, the
connect message is returned instead.
• Analog, DTI, and ISDN outgoing trunks: For incoming DID calls, the
answer and disconnect supervisor (SUPN) of the outgoing trunk is forced
to NO. The EOD or ODT timer simulates the return of answer
supervision.