Cisco Unified Communications Manager (CallManager)

Document ID: 22439

Contents

Introduction
Prerequisites
      Requirements
      Components Used
      Conventions
Problem
Solution
      Voice Mail Maximum Hop Count
      Advanced Call Forward Hop Flag
Related Information

Introduction

This document addresses a configuration problem wherein the caller hears a busy signal when a call is routed to reach certain Cisco Unity voicemail ports.

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

This document applies to Cisco CallManager 3.0(9) and later, and all versions of Cisco Unity.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Conventions

For more information on document conventions, refer to the Cisco Technical Tips Conventions.

Problem

If the Voice Mail Maximum Hop Count and the Advanced Call Forward Hop Flags parameters are not used properly, users can experience a busy signal when they try to reach the voicemail and some ports might not be used at all.

Solution

The solution to this problem is explained in detail here.

Voice Mail Maximum Hop Count

Users may experience a busy signal when the Voice Mail Maximum Hop Count is set for a value less than the number of voicemail ports. This parameter identifies how many ports to attempt to send a voicemail call to. It starts with the first voicemail port, and then, if it is busy or rings with no answer, it tries the next port and so on, until the limit has been reached. However, the caller can get a busy signal even if there are still more ports available that were not included in the limit value. This value should be equal to the number of voice ports that you have in use.

1. In Cisco CallManager Administration, click Service > Service Parameters.

2. In the Server list on the Service Parameters Configuration page, click the appropriate server.

3. In the Services list, click Cisco CallManager. The list of parameters appears.

4. Find the Voice Mail Maximum Hop Count and set it equal to the number of voice ports being used.

5. If the value is changed, click Update to save the setting.

6. Restart Cisco CallManager service on all CallManager servers to ensure the values take effect.

Advanced Call Forward Hop Flag

If this flag is set to True, Cisco CallManager call forwarding logic skips the busy or unregistered voice mail port when it chooses the next voice mail port. The call then gets extended to the available voice mail port so the voice mail ports gets chosen more efficiently. But, if the flag is set to False, Cisco CallManager call forwarding logic does not skip the busy or unregistered voice mail port. The call extends to the busy or unregistered voice mail port and waits until the busy or unregistered voice mail port rejects the call. The call then gets forwarded to the next voice mail port. It is always better to turn on this flag.

Also, the Cisco Unity status monitor may show the port as free while users get busy signals when they try to access the voicemail. If you experience this symptom, forward the last port back to the first port. Also, increase the Voice Mail Maximum Hop Count to double the number of ports. This configuration causes Cisco CallManager to check the ports twice to determine if they are available. The second time around the ports are usually available through the status table.

1. In Cisco CallManager Administration, click Service > Service Parameters.

2. In the Server list on the Service Parameters Configuration page, click the appropriate server.

3. In the Services list, click Cisco CallManager. The list of parameters appears.

4. Find the Advanced Call Forward Hop Flag and verify that it is set to the correct value. Forward the last port to the first port and increase the Voice Mail Maximum Hop Count in order to double the number of ports.

5. If the value is changed, click Update to save the setting.

6. Restart Cisco CallManager service on all CallManager servers to ensure the values take affect.

   

Related Information

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