II-digits basics

Last Updated : Sep 08, 2012 |

String description

II-digits is a 2-digit string that ISDN PRI provides for an incoming call. II-digits delivery is a widely available ISDN PRI AT&T Network service. This service is bundled with ANI delivery and tariffed under the MEGACOM 800® and MultiQuest 800® INFO-2 features to provide information on call origination. R2-MFC Call Category digits, when available, are treated as II-digits for routing.

Leading zeros are significant. For example, the II-digits value 02 that is associated with a call does not match the digit string 2 in a vector step.

Use with a VRT

As is true for ANI routing and collected-digit routing, II-routing digits can be compared against entries in a Vector Routing Table.

Use of wildcards

The II-digits string used in a vector step or a vector routing table can contain either the + or ? wildcard.

VDN Return Destination preservation

When a call is returned to vector processing as a result of the VDN Return Destination feature, the II-digits are preserved.

Call types associated with II-digits

The following calls have associated II-digits values:

  • Incoming ISDN PRI calls that include II-digits.

  • Incoming ISDN PRI Tie Trunk DCS or non-DCS calls that include II-digits.

Note:

Since tandeming of II-digits is only supported if the trunk facilities used are ISDN PRI, traditional DCS does not support II-digits transport but DCS Plus, that is, DCS over PRI, supports II-digits transport.

Internal transfer to a VDN

When a call with II-digits is transferred internally to a VDN, the following outcomes can occur:

  • If the transfer completes before the call reaches the II-digits conditional, the II-digits value of the originator of the call is used.

  • If the transfer completes after the call reaches the II-digits conditional, the II-digits value of the terminal executing the transfer is used. Under normal circumstances, there are no II-digits for a terminal that executes a transfer.

Tip:

To ensure that the originator II-digits is preserved, add a filler step such as wait with silence to the beginning of the vector. In this way, a transfer can be completed before the II-digits conditional is encountered.