MERLIN LEGEND Communications System Release 5.0
Feature Reference
555-650-110
Issue 1
June 1997
Features
Page 472
Primary Rate Interface (PRI) and T1
Mode Differences
3
6
Key Mode
3
6
Routing by dial plan for PRI or T1 data lines is not supported in Key mode.
Behind Switch Mode
3
6
T1 data lines are not supported in Behind Switch mode.
Considerations and Constraints
3
6
General
3
6
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; 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—Station
Identification/Automatic Number Identification (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)
module in the control unit must be different from the numbers assigned to other
channels in the same B-channel group and must be the same number as that
supplied by the PRI service provider.
An invalid timer value entered in system programming results in truncation to the
closest valid value. If, for example, 45 is entered for a counter that ranges from 0
to 30 seconds, 4 is recorded.
