Configure CME for Call Forward to an External Number

Introduction

Call forwarding in Cisco CallManager Express sometimes requires special configuration in order to account for changes in caller ID or various supplementary services protocols used by ISDN or Session Initiation Protocol (SIP). This document describes common solutions for call forward failure on the Cisco Unified CallManager Express platform.

Prerequisites

Requirements

Cisco recommends that you have knowledge of Cisco CallManager Express.

Components Used

This document is not restricted to specific software and hardware versions.

Conventions

Refer to Cisco Technical Tips Conventions for more information on document conventions.

Call Forward to External Number Fails

When a user tries to forward a call to an external PSTN number or mobile using the call-forward noan command, the user gets a dial tone and the call forward fails. But at the same time, a call can be made from the internal number to the same external PSTN or mobile number.

Faliure over ISDN PRI

When the outgoing PSTN connection is ISDN PRI, the long distance calls with any Calling Line ID (CLID) other than the one specified by the Telco fails. When a call is forwarded, the calling number remains the same and the Telco does not allow the call to complete because it expects a different calling number. That is the number from which the call is redirected. In order to resolve this problem, configure the translation rule to force ANI for outgoing calls, which should be the Telco expected value.

Configure the Voice Translation Rule

In order to translate the calling party number, you can use a voice translation-rule .

Create a voice translation-rule in global configuration mode. For more information on voice translation rules, refer to Voice Translation Rules.

voice translation-rule 100
 rule 1 /\(^3...\)/ /8282100\1/

!--- This rule changes extensions that match 3000-3999 !--- adds 8282100 as a prefix. Refer to Voice Translation Rules !--- for more details.

voice translation-profile 1
 translate calling 100

ephone-dn  8 
 number 3007 
 translation-profile outgoing 1

!--- The translation profile needs to be !--- applied to all ephone-dns that can make outbound calls.

This allows you to forward calls to external PSTN numbers or mobile numbers which are not originated from internal callers.

Note:  If you have a Cisco CallManager Express router that runs Cisco IOS Software Release12.(4)15T, and if the redirect from call park to another number fails, you need to downgrade to Cisco IOS Software Release12.(4)9T4.

Related Information

• Voice Technology Support
• Voice and Unified Communications Product Support
• Troubleshooting Cisco IP Telephony
• Technical Support & Documentation - Cisco Systems