AT&T MERLIN LEGEND Communications System PBX System Planning Manual page 82

Trunks
Timers and Counters
Planning Form Instructions
Under the "Terminal Equipment Identifier (TEI)" heading on Form 3c:
1 . Check "0" to keep the factory-set TEI.
2 .
To change the factory-set TEI from 0, write a value from 1 to 63 in the
space provided.
Timers and counters are used to ensure that the system takes the appropriate
corrective action when no response is received from the network before the
programmed settings have expired.
CAUTION
Since incorrect settings could have an adverse effect on the operation of
lSDN-PRl facilities, consult your A T&T representative or authorized dealer
before you make any changes. The factory-set thresholds are standard
settings and should rarely be changed.
The timers and counters, descriptions, factory settings, and allowable
thresholds are shown in Table 3-5.
Trunk Options 3-27