Cisco Systems OL-14619-01 Impact of Non-Delivery of RDNIS on Voice Mail Calls Routed via AAR

Chapter 6 Integrating Cisco Unity with the Phone System

Integrating with Cisco Unified Communications Manager Express (by Using SCCP or SIP)

Call forward to internal greeting	When the Cisco Unified SRST router uses FXO/FXS connections to the
	PSTN and a call is forwarded from a branch office to Cisco Unity, the
	internal greeting cannot play. Because the PSTN provides the calling
	number of the FXO line, the caller is not identified as a subscriber.
Call transfers	Because an access code is needed to reach the PSTN, call transfers from
	Cisco Unity to a branch office will fail.
Identified subscriber messaging	When the Cisco Unified SRST router uses FXO/FXS connections to the
	PSTN and a subscriber at a branch office leaves a message or forwards
	a call, the subscriber is not identified. The caller appears as an
	unidentified caller.
Message waiting indication	MWIs are not updated on branch office phones, so MWIs will not
	correctly reflect when new messages arrive or when all messages have
	been listened to. We recommend resynchronizing MWIs after the WAN
	link is reestablished.
Message notification	Because an access code is needed to reach the PSTN, message
	notifications from Cisco Unity to a branch office will fail.
Routing rules	When the Cisco Unified SRST router uses FXO/FXS connections to the
	PSTN and a call arrives from a branch office to Cisco Unity (either a
	direct or forwarded call), routing rules will fail.

When the Cisco Unified SRST router uses PRI or BRI connections, the caller ID for calls from a branch office to Cisco Unity may be the full number (exchange plus extension) provided by the PSTN and therefore may not match the extension of the Cisco Unity subscriber. In this case, you can let

Cisco Unity recognize the caller ID by using alternate extensions or by using extension remapping. For information on extension remapping, see the “Remapping Extension Numbers” section of the “Managing System-Wide Settings” chapter in the applicable System Administration Guide for

Cisco Unity Release 5.x, available at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/prod_maintenance_guides_list.html.)

When using Cisco Unified SRST, Redirected Dialed Number Information Service (RDNIS) must be supported.

For information on setting up Cisco Unified SRST routers, see the “Integrating Voice Mail with Cisco Unified SRST” section of the Cisco Unified SRST System Administrator Guide at http://www.cisco.com/en/US/products/sw/voicesw/ps2169/products_installation_and_configuration_g uides_list.html.

Impact of Non-Delivery of RDNIS on Voice Mail Calls Routed via AAR

RDNIS needs to be supported when using Automated Alternate Routing (AAR).

AAR can route calls over the PSTN when the WAN is oversubscribed. However, when calls are rerouted over the PSTN, RDNIS can be affected. Incorrect RDNIS information can affect voice mail calls that are rerouted over the PSTN by AAR when Cisco Unity is remote from its messaging clients. If the RDNIS information is not correct, the caller will not reach the mailbox of the dialed user but will instead receive the automated attendant prompt, and the caller might be asked to reenter the extension number of the party they want to reach. This behavior is primarily an issue when the telephone carrier is unable to ensure RDNIS across the network. There are numerous reasons why the carrier might not be able to ensure that RDNIS is properly sent. Check with your carrier to determine whether it provides guaranteed RDNIS delivery end-to-end for your circuits. The alternative to using AAR for oversubscribed WANs is simply to let callers hear reorder tone in an oversubscribed condition.

	Design Guide for Cisco Unity Release 5.x
OL-14619-01		6-21