Table Of Contents

Introduction

Integration Description

Call Information

Integration Functionality

Integrations with Multiple Phone Systems

Introduction

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See the following sections in this chapter:

•Integration Description

•Call Information

•Integration Functionality

•Integrations with Multiple Phone Systems

Integration Description

The Cisco Unified Communications Manager (CM) (formerly known as Cisco Unified CallManager) SCCP integration makes connections through a LAN or WAN. A gateway provides connections to the PSTN.

For a list of supported versions of Cisco Unified CM that are qualified to integrate with Cisco Unity by Skinny Call Control Protocol (SCCP), see the SCCP Compatibility Matrix: Cisco Unity, the Cisco Unity-CM TSP, Cisco Unified Communications Manager, and Cisco Unified Communications Manager Express at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_device_support_tables_list.html.

Call Information

The phone system sends the following information with forwarded calls:

•The extension of the called party

•The extension of the calling party (for internal calls) or the phone number of the calling party (if it is an external call and the system uses caller ID)

•The reason for the forward (the extension is busy, does not answer, or is set to forward all calls)

Cisco Unity uses this information to answer the call appropriately. For example, a call forwarded to Cisco Unity is answered with the personal greeting of the subscriber. If the phone system routes the call without this information, Cisco Unity answers with the opening greeting.

Integration Functionality

The Cisco Unified CM SCCP integration with Cisco Unity provides the following features:

•Call forward to personal greeting

•Call forward to busy greeting

•Caller ID

•Easy message access (a subscriber can retrieve messages without entering an ID; Cisco Unity identifies a subscriber based on the extension from which the call originated; a password may be required)

•Identified subscriber messaging (Cisco Unity automatically identifies a subscriber who leaves a message during a forwarded internal call, based on the extension from which the call originated)

•Message waiting indication (MWI)

The functionality of this integration may be affected by the issues described below.

Use of Cisco Unified Survivable Remote Site Telephony (SRST) Router

When a Cisco Unified Survivable Remote Site Telephony (SRST) router is part of the network and the Cisco Unified SRST router takes over call processing functions from Cisco Unified CM (for example, because the WAN link is down), phones at a branch office can continue to function. In this situation, however, the integration features have the following limitations:

•Call forward to busy 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 busy greeting cannot play.

•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.

•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/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. If this is the case, you can let Cisco Unity recognize the caller ID by using alternate extensions.

Redirected Dialed Number Information Service (RDNIS) needs to be supported when using SRST.

For information on setting up Cisco Unified SRST routers, refer to the "Integrating Voice Mail with Cisco Unified SRST" chapter of the applicable Cisco Unified SRST System Administrator Guide at http://www.cisco.com/en/US/products/sw/voicesw/ps2169/products_installation_and_configuration_guides_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 call will not reach the voice mail box of the dialed subscriber but will instead receive the automated attendant prompt, and the caller might be asked to reenter the extension number of the party they wish 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.

(Cisco Unified CM 4.2(3) and Later 4.2(x) Releases Only) Impact of the Original Calling Party on Transfer Feature

For Cisco Unified CM 4.2(3) and later 4.2(x) releases, when the Original Calling Party on Transfer feature is enabled, the following impacts occur:

•Calls that Cisco Unity transfers to a phone can display the original calling party information rather than the calling party information of the Cisco Unity voice messaging port.

•Live reply will not function correctly.

•Transfers to subscribers on other networked Cisco Unity systems will not succeed.

•Cross-box log in will not succeed.

To enable the Original Calling Party on Transfer feature, in Cisco Unified CM Administration, on the Service Parameters Configuration page for the Cisco Unified CM server, you must set the Display Original Calling Number on Transfer from Cisco Unity service parameter to True.

Note that if the Original Calling Party on Transfer feature is enabled on Cisco Unified CM, a transfer loop can occur when the following happens:

1. Caller A calls user B.

2. User B has set the extension to forward calls to extension C. So Cisco Unity transfers the call to extension C and the call displays the number of caller A.

3. Extension C rings and is not answered.

4. Because the calling number of caller A is displayed, Cisco Unity returns the call to user B, and a transfer loop is created.

To avoid a transfer loop under this condition, users must avoid forwarding calls to extensions that will not be answered.

Also note that if the Original Calling Party on Transfer feature is disabled on Cisco Unified CM, the call can be disconnected when the following happens:

1. Caller A calls user B.

2. User B has set the extension to forward calls to extension C. So Cisco Unity transfers the call to extension C and the call displays the number of the Cisco Unity voice messaging port that is handling the call.

3. Extension C rings and is not answered.

4. Because the calling number of a voice messaging port is displayed, Cisco Unity disconnects the call as a forwarded notification call.

To avoid disconnecting calls under this condition, users must avoid forwarding calls to extensions that will not be answered.

Integrations with Multiple Phone Systems

Cisco Unity can be integrated with two or more phone systems at one time. For information on the maximum supported combinations and instructions for integrating Cisco Unity with multiple phone systems, see the Multiple Phone System Integration Guide for Cisco Unity 5.0 at http://www.cisco.com/en/US/products/sw/voicesw/ps2237/products_installation_and_configuration_guides_list.html.