AT&T DS1/DMi/ISDN-PRI manual Field

	ADMINISTRATION OPTIONS AND REQUIREMENTS — SYSTEM 85	7-29
Field 4	Retry permits multiple attempts to seize a busy trunk from the specified trunk
	group.

This field is primarily applicable for those trunk groups routed over analog facilities and use one of the following trunk types: 41, 42, 43, 46, or 47. Depending on the particular configuration, RETRY may or may not be applicable for ISDN applications. Field encodes and their descriptions are:

0 When multiple retry is not desired RETRY NOT ACTIVE. The ISDN-PRI protocol contains retry capability. When signaling type 20 is selected, 0 encode is required.

1Recommended for ISDN applications where the 40-series of trunk types is used. Encode 1 enables a double retry and thus provides slightly improved call completion, particularly for large trunk groups that span across more than one transmission facility.

Field 5	Not	applicable for ISDN applications. Therefore, the required option must be 0 for
	not	active.
Field 6	Not	applicable for ISDN applications. Therefore, the required option must be 0	for
	not	active.
Field 7	Not	applicable for ISDN applications. Therefore, the required option must be 0	for

no failure threshold. See field 17 of procedure 107, word 5, for related information.

NOTE: This field is only applicable for analog trunk facilities. It permits the user to establish a trunk failure threshold that, when exceeded, will generate an alarm. The threshold limit will affect service availability and, on an indirect basis, the customer’s maintenance costs.