Requirements For Dialing Pauses - Avaya Communication Server 1000 Series Reference

Requirements for dialing pauses

When outpulsing to the main circuit switch and to a TTTN, ESN nodes are occasionally required
to pause at various points in the digit string to allow for trunk access and register attachment.
Failure to pause causes missed digits and calls to connect to wrong numbers or to be lost
altogether.
ESN software provides for pauses following trunk access codes in the Network Alternate Route
Selection (NARS) translation tables. The general rule is that each trunk access code outpulsed
must be followed by a pause. However, there are a number of situations where the pause is
not required.
In determining whether the pause is required, you must consider the following:
• what type of circuit switch is reached in the dialing
• what piece of equipment is accessed
Important:
IMPORTANT!
Pauses are supported on analog and DTI trunks, but are not supported on ISDN trunks. The
asterisk (*) used to introduce a pause is supported only on analog and DTI trunks, but not
supported on ISDN trunks. On ISDN trunks, if OPAO feature is enabled, the asterisk (*) is
outpulsed as a called party digit.
Pauses are not required in the following situations:
• The access code connects a SXS circuit switch to an SXS circuit switch.
• The access code connects a system circuit switch to any other circuit switch, providing
that subsequent pauses are not required.
• The access code is 9 for a CO trunk by a Centrex circuit switch, but not for other CO
trunks.
• The access code is for an automatic route selection on any circuit switch.
A potential problem can occur when a trunk access code requiring a pause is made after the
call is routed through one or more system switches. While the ESN node need not pause
between access codes for routing through the system switches, if it does not pause, a problem
occurs where the pause is required.
The connected switches insert the proper delay after the access code before resending digits.
However, the time spacing between digits is not maintained. The trailing digits "catch up" with
the leading digits. The time delay required after an access code is eliminated. To avoid this
problem, the ESN node must insert pauses after each access code for this call routing.
Electronic Switched Network Reference — Signaling and Transmission
Requirements for dialing pauses
August 2011 27