Cisco CallManager System Guide, Release 3.3(2)
SMDI Voice Mail Integration
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SMDI Voice Mail Integration

Table Of Contents

SMDI Voice Mail Integration

SMDI Voice Mail Integration Requirements

Port Configuration for SMDI

Cisco Messaging Interface Redundancy

SMDI Configuration Checklist

Where to Find More Information


SMDI Voice Mail Integration


Simplified Message Desk Interface (SMDI) defines a way for a phone system to provide voice-mail systems with the information that the system needs to intelligently process incoming calls. Each time that the phone system routes a call, it sends an SMDI message through an EIA/TIA-232 connection to the voice-mail system that tells it the line that it is using, the type of call that it is forwarding, and information about the source and destination of the call.

The SMDI-compliant voice-mail system connects to Cisco CallManager in two ways:

Using a standard serial connection to the Cisco CallManager

Using POTS line connections to a Cisco analog FXS gateway

This section covers the following topics:

SMDI Voice Mail Integration Requirements

Port Configuration for SMDI

Cisco Messaging Interface Redundancy

SMDI Configuration Checklist

Where to Find More Information

SMDI Voice Mail Integration Requirements

The Cisco Messaging Interface service allows you to use an external voice-mail system with Cisco CallManager Release 3.0 and later.

The voice-mail system must meet the following requirements:

The voice-mail system must have a simplified message desk interface (SMDI) that is accessible with a null-modem EIA/TIA-232 cable (and an available serial port).

The voice-mail system must use analog ports for connecting voice lines.

The Cisco CallManager server must have an available serial port for the SMDI connection.

A Cisco Access Analog Station Gateway, Cisco Catalyst 6000 24-port FXS gateway, or Cisco VG200 gateway that is configured with FXS ports must be installed and configured.

You must ensure that gateways are configured in a route pattern. Refer to the "Route Pattern Configuration" chapter in the Cisco CallManager Administration Guide for more information.

Port Configuration for SMDI

Previous releases of Cisco CallManager required a specific configuration for voice-mail integration using the SMDI and the Cisco Messaging Interface. This older configuration method for FXS ports required each individual port of an analog access gateway (Cisco AS-2, Cisco AS-4, Cisco AS-8, or Cisco Catalyst 6000 24 Port FXS gateway) to be explicitly configured as a separate entry in a route group. The relative position within the route list/route group of each analog access port determined the SMDI port number that was reported by the Cisco Messaging Interface.

For Cisco CallManager Release 3.0(5) and later releases, you can configure the SMDI port number through Cisco CallManager Administration.


Note You can still use the older style of configuration for FXS ports for voice mail, as long as the new SMDIPortNumber fields in the port configuration window for analog access ports are not configured. If the SMDIPortNumber field is not configured, the default specifies 0. This default value applies for these fields for any upgrade of the current database configuration, and existing functionality is not affected.


To use the new SMDIPortNumber configuration, perform the following steps:

1. Modify each analog access port that connects to the voice-mail system and set the SMDIPortNumber equal to the actual port number on the voice-mail system to which the analog access port connects.

With this first step, you do not need to change any route lists/route groups. The newly configured SMDIPortNumber(s) override any existing route list/route group configuration that was set up for the devices that connect to the voice-mail system.

2. To take advantage of reduced Cisco CallManager signaling requirements with this new configuration, change each analog access device that is in a route group that was set up for the older method of configuration from multiple entries that identify individual ports on the device to a single entry in the route group that identifies "All Ports" as the port selection.

The selection order of each of these device entries differ or do not differ.

ReorderRouteList Service Parameter

An added mechanism allows choosing devices in a route group in a "round-robin" fashion. To take advantage of this feature, configure the devices as follows:

1. Configure all the analog access that connect to the voice-mail system in a single route group, with each device in the route group using "All Ports" and having the same selection order (that is, selection order 1).

2. Set the Cisco CallManager service parameter ReorderRouteList to T (True).

When a call is extended via the route list, Cisco CallManager offers it to the devices in the route group in sequential order. Then, Cisco CallManager re-orders the device list (route group) by taking the first device in the list and moving it to the end of the list.

The next call extended via the route list receives the re-ordered list and thus extends the call to a different device (compared to the previous call). Each call attempt communicates with a subsequent device first. With this mechanism, use all devices in the group in a "round-robin" fashion instead of the current "top-down" only mechanism.

Enabling the ReorderRouteList service parameter does not affect route list/route configurations that have explicitly set different selection orders for devices in a route group for setting up an ordered device selection (that is, the older method of voice-mail configuration).

Cisco Messaging Interface Redundancy

Most voice-mail systems that rely on an EIA/TIA-232 serial cable (previously known as a RS-232 cable) to communicate with phone systems only have one serial port. You can achieve Cisco Messaging Interface redundancy by running two or more copies of the Cisco Messaging Interface service on different servers in a Cisco CallManager cluster and using additional hardware including a data splitter that is described later in this section.

Each copy of Cisco Messaging Interface connects to a primary and backup Cisco CallManager and registers to the Cisco CallManager by using the same VoiceMailDn and VoiceMailPartition service parameter values. The Cisco Messaging Interface with the higher service priority (the active Cisco Messaging Interface service) handles the SMDI responsibilities. If this Cisco Messaging Interface encounters problems, another one can take over. Figure 23-1 illustrates one of many layouts that provide Cisco Messaging Interface redundancy.

Figure 23-1 Cisco Messaging Interface Redundancy


Note To achieve Cisco Messaging Interface redundancy, you must have a device such as the data splitter as shown in Figure 23-1 to isolate the SMDI messaging from the various Cisco Messaging Interface services. You cannot use an ordinary Y-shaped serial cable to combine the EIA/TIA-232 streams together.


The data splitter that you connect to your voice-mail system, such as the B&B Electronics modem data splitter (models 232MDS and 9PMDS), must have the following characteristics:

High reliability

Bidirectional communication

Minimal transmission delay

No external software support (desired)

No extra EIA/TIA-232 control line operations (desired)

The 232MDS includes two DB25 male ports and one DB25 female port. The 9PMDS represents a DB9 version of this modem data splitter. These switches enable Cisco Messaging Interface redundancy with the following limitations when you set the ValidateDNs Cisco Messaging Interface service parameter to Off:

SMDI messages (MWI messages) from voice-mail systems get broadcast to both Cisco Messaging Interfaces. Both Cisco Messaging Interfaces send MWI messages to the Cisco CallManager to which they are connected. This produces an extra load on the database and network traffic (if the Cisco Messaging Interface and Cisco CallManager are on different servers).

Two Cisco Messaging Interfaces cannot transmit SMDI messages simultaneously. Under extreme circumstances, you may experience network failures that break your Cisco CallManager cluster into two unconnected pieces. In the unlikely event that this occurs, both copies of Cisco Messaging Interface may become active, which leads to the possibility that they may simultaneously transmit SMDI messages to the voice-mail system. If this happens, the collision could result in an erroneous message to the voice-mail system, which may cause a call to be mishandled.

SMDI Configuration Checklist

Table 23-1 provides an overview of the steps that are required to integrate voice-mail systems using SMDI.

Table 23-1 SMDI Configuration Checklist 

Configuration Steps
Related Procedures and Topics

Step 1 

Add and configure gateway ports.

If you are configuring an Octel system and you are using a Cisco Catalyst 6000 24 Port FXS Analog Interface Module or AST ports, make sure to set the Call Restart Timer field on each port to 1234.

Adding Gateways to Cisco CallManager, Cisco CallManager Administration Guide

Step 2 

Create a route group and add the gateway ports that you configured in Step 1 to the route group.

Adding a Route Group, Cisco CallManager Administration Guide

Step 3 

Create a route list that contains the route group configured in Step 2.

Adding a Route List, Cisco CallManager Administration Guide

Step 4 

Create a route pattern.

Adding a Route Pattern, Cisco CallManager Administration Guide

Step 5 

Activate, configure, and run the Cisco Messaging Interface service.

Cisco CallManager Serviceability Administration Guide

Service Parameters Configuration, Cisco CallManager Administration Guide

Step 6 

Configure Cisco Messaging Interface trace parameters.

Cisco CallManager Serviceability Administration Guide

Cisco CallManager Serviceability System Guide

Step 7 

Configure your voice-mail system and connect the voice-mail system to Cisco CallManager with an EIA/TIA-232 cable.

Refer to the documentation provided with your system.


Where to Find More Information

Additional Cisco Documentation

Cisco Messaging Interface Configuration, Cisco CallManager Administration Guide

Service Parameters Configuration, Cisco CallManager Administration Guide

Cisco CallManager Serviceability Administration Guide

Cisco CallManager Serviceability System Guide

Cisco IP Telephony Network Design Guide