AT&T MERLIN LEGEND Installation & Maintenance Manual page 48

System Description
Dial Tone determines whether the system returns a dial tone
to the remote end of the line:
yes (factory setting)—a dial tone is sent to the remote end
no—a dial tone is not sent to the remote end
Answer Supervision Time sets a time limit in milliseconds
(ms) for the remote station to signal the calling station:
300 ms (factory setting)
20–4800 ms (increments of 20 ms)
Disconnect Time sets a time limit in milliseconds for the
release of the E or M lead:
300 ms (factory setting)
140–2400 ms (increments of 10 ms)
Direct Inward Dialing Trunks
Direct inward dialing (DID) trunks allow incoming calls to reach
specific individuals or facilities in the system without the
assistance of a system operator. DID trunks are available only in
the Hybrid/PBX mode. They are connected to the system on an
800 DID module.
With DID service, the customer reserves blocks of DID numbers
from the local telephone company. The DID number should
correspond to the extension number for an individual or a calling
group, or to the code for Remote Access or pool dial-out.
CAUTION:
DID numbers that correspond to pool dial-out codes (or
facility access codes) can be used to avoid toll restriction,
leading to toll abuse and/or fraud (see "Security of Your
System" under "Customer Support Information" in the front of
this book).
Control Unit 1-17