What is the full form of MWI


This document provides an example configuration for a VG248 port to send the correct signal to light the Message Indicator (MWI) on a Caller ID field connected to an analog phone.



Make sure Cisco CallManager is integrated with your voicemail system before attempting this configuration.

Components used

The information in this document is based on the following software and hardware versions:

  • Cisco VG248 Analog Telephone Gateway

  • VG248 software version 1.3

  • Analog telephones

  • Caller ID field

The information in this document was produced by the devices in a specific laboratory environment. All devices used in this document started with an empty (standard) configuration. With your network up and running, make sure you understand the potential implications of a command.


For more information about document conventions, see Cisco Technical Tips Conventions.

Background information

The VG248 gateway is a product supported by Cisco AVVID (Architecture for Video, Voice, and Integrated Data) that enables companies to continue using their analog devices with the latest IP telephony technology. The VG248 is a gateway for the use of analog telephones, fax machines, modems, voicemail systems and loudspeaker telephones within a company, which is based on Cisco CallManager.

If an analog telephone system is connected in-line with Caller ID boxes with Message Waiting Indicators (MWI), ensure that the Caller ID boxes are receiving the appropriate signal from the telephone company in order to successfully deliver the Message Waiting Indicators (MWI) are lit, indicating that voicemail is waiting. The two types of signals that are transmitted by telephone companies are Stutter tones and Frequency-Shift Keying (FSK) tones. Although these tones are used to enable Message Indicator (MWI) when a message is recorded, they will not work for all telephone company-supplied Caller ID box models.

Note: The power consumption of the VG248 is between 50 W and 160 W. This depends on the status of the connected telephones.

The VG248 supports several methods of sending MWI messages to analog telephones. Since different types of analog telephones are connected to the VG248, you can change the MWI type per port. So if you have analog telephones with MWI lamps, you can use the MWI lamp to notify users of the display of messages. You can also play a sound when users pick up their phone.

These are the methods supported by the VG248:

  • Lamp (90 volt signal): The lamp on the phone lights up.

  • Caller ID (FSK Tone) (Caller ID (FSK Tone): Uses the caller ID mechanism to send MWI messages to the phone's LCD screen.

  • Stutter (stutter tone): Sounds are played when the user picks up the phone.

  • Lamp + stutter: The lamp lights and emits a tone.

  • Caller ID + stutter: Sends a message to the LCD screen and plays a tone.

  • None (None): MWI information is not sent.


Follow these steps to configure the VG248 port to support Caller ID (FSK Tone) in a Caller ID field inline with an analog phone.

  1. From the main menu, select Configure.

  2. Choose Telephony off.

  3. Choose Port-specific parameters.

  4. Use the arrow keys to select the port you want to configure, and then press Enter key.

  5. Choose the MWI method.

  6. Select the option Caller ID.


No verification process is currently available for this configuration.


This section provides information on troubleshooting your configuration.

You can set the VG248 to log much more detailed information (information, errors or warnings) and to log on to specific ports. To set logging levels and select ports, do the following:

  1. From the main menu, select Diagnostics (diagnosis).

  2. Choose Event log.

  3. Choose Set logging levels.

  4. Under Set Logging Levels, select the options Voicemail (VM) and SCCP Errors + Warnings + Info + Trace off.

  5. In the Set Logged Port field, select a port to test on.

  6. Select in the menu Diagnostics to display the New option.

  7. Place a call on the analog phone using the selected extension with the Caller ID box and record a message. The events will be displayed in the VG248 Telnet session and the MWI should be lit.

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