Lucent Technologies MERLIN LEGEND Release 7.0 Feature Reference page 607

MERLIN LEGEND Communications System Release 7.0
Feature Reference 555-670-110
Features
Primary Rate Interface (PRI) and T1
If none of these is capable of providing the system clock, the communications
system searches 800 NI-BRI and 100D modules for a clock source, starting from
the first module in the system and ending with the last module. The clock is
chosen with the following order of preference:
1. Loop clock source on an 800 NI-BRI or 100D module.
2. Local clock source on an 800 NI-BRI or 100D module.
3. Local clock source on the processor module.
Mode Differences
Key Mode
Routing by dial plan for PRI or T1 data lines is not supported in Key mode.
Behind Switch Mode
T1 data lines are not supported in Behind Switch mode.
Considerations and Constraints
General
If a B-channel is not available when a call is placed, a fast busy tone is returned.
While the tone is in progress, the line is considered busy. If the originator goes on
hook while the tone continues, the call is ended and the line is idled. Otherwise,
the call appearance is removed and the line is idled 15 seconds after the tone is
applied.
A telephone is considered busy when: no SA button (aside from Originate Only
buttons) is available, Do Not Disturb is activated, the extension either is being
programmed or is in forced idle, or the alarm clock is being set. The caller hears a
busy tone, and the call receives coverage, if programmed.
A PRI line can be assigned to only one B-channel group.
If the inside dial plan uses extension numbers with different numbers of digits—for
example, both 3-digit extension numbers and 4-digit extension numbers—
SID-ANI or other extension identification services (Release 4.2 and later systems)
may not work properly.
The PRI telephone number assigned to each channel must be unique within the
same B-channel group and different from the associated test number. Also, the
number of each channel must be the same number as that supplied by the PRI
service provider. The test telephone number assigned for each 100D (DS1)
Issue 1
April 1999
547