User`s guide

Pipeline 75 Voice Features
How outgoing voice calls are handled
A-4 Preliminary January 30, 1998 Pipeline User’s Guide
The sections that follow note differences in voice features for certain types of
ISDN service and for certain switches. Because standardized ISDN services,
such as National ISDN-1 (NI-1), are becoming more common, these differences
are becoming less frequent. A separate document published on the Ascend web
site, “Ordering ISDN Service for the Ascend Pipeline 25, 75, and 85,” explains
how to order ISDN Basic Rate Interface (BRI) service—the affordable ISDN
service for which the Pipeline is designed—and lists advantages and
disadvantages of different types of BRI service. If your telephone company offers
more than one type of BRI service, you can use the lists of advantages and
disadvantages to determine which type is best for you.
How outgoing voice calls are handled
When an ISDN telephone line is configured properly for the Pipeline, each B
channel can carry either voice or data. When a B channel is used for voice, it can
carry a single voice call.
The voice-handling features of the Pipeline make it easy to make outgoing voice
calls:
• If neither B channel is currently in use, you can make a voice call by picking
up the receiver of a telephone connected to either analog port.
• If a single B channel is currently in use for a data call, you can make a voice
call by picking up the receiver of a telephone connected to either analog port.
The other B channel is then used for the call.
– Exception: If the switch is a Northern Telecom DMS-100 and the value
of the Phone Num Binding parameter is Yes, you cannot make the call if
the currently used B channel and the analog port to which the phone is
connected both use the same telephone number.
• If a single B channel is currently in use for a voice call, you can make a voice
call on the other telephone number by picking up the receiver of a telephone
connected to the other analog port. The other B channel is then used for the
call.
– Exception: If the type of ISDN service is AT&T Custom Point-to-Point,
there can be only one voice call at a time. Because AT&T Custom Point-
to-Point service includes only one telephone number, all outgoing voice
calls use that number.