ISTN - Interconnection Screening Telephone Number

Identifies the telephone number used for billing or translation purposes.

VALID ENTRIES:

Telephone number format

NPA-NXX-XXXX

NOTE 1: This telephone number would be customer owned and identified during customer/provider pre-negotiations.

USAGE: This field is optional.

NOTE 1: Prohibited when the ACT field is “D”, otherwise optional.

DATA CHARACTERISTICS: 10 numeric characters (excluding 2 preprinted hyphens)

EXAMPLE: 3 1 4 - 8 3 7 - 1 2 3 4