How to Configure Music on Hold in Cisco Phone Systems

On a Cisco phone system, the music callers hear while they wait on hold, after a transfer or while parked comes from the Music on Hold (MOH) feature, not from the handset. This guide covers two common platforms: Cisco Unified Communications Manager (CUCM) and Cisco Unified Communications Manager Express (CME) running on an IOS router. Cloud-hosted Cisco calling services are managed through their own admin portals and are not covered here.

Before you start

First confirm which platform you administer. On CUCM, hold music is streamed by the Cisco IP Voice Media Streaming App service on one or more of your own cluster nodes. On CME, the router plays a file stored in its flash memory. In both cases the audio is served from your own equipment, not from an outside service.

• Administrator access to Cisco Unified CM Administration and Cisco Unified Serviceability (CUCM), or privileged CLI access to the router (CME).
• An audio file you are permitted to play to callers. Public playback rights for commercial music are your responsibility to verify.
• For CME: an .au or .wav file containing 8-bit, 8 kHz G.711 audio (mu-law or a-law), mono.
• For CUCM: the upload formats listed in the documentation for your exact release. WAV is the commonly accepted format, and the server converts it into the codecs it streams.
• For CME: a TFTP, FTP or SCP server, or another supported method, to copy the file to router flash.
• A note of the current MOH settings and file names, so you can revert if needed.

A note on terms: call waiting is the tone a user hears when a second call arrives during an active call. Callers kept waiting on hold hear MOH. If callers wait in a contact center queue, that audio may be controlled by the contact center application's scripts rather than by MOH, so check there first.

Step-by-step instructions

Cisco Unified Communications Manager

• 1. In Cisco Unified Serviceability, open Tools > Service Activation, select the node that should stream music, and confirm that Cisco IP Voice Media Streaming App is activated.
• 2. In Cisco Unified CM Administration, go to Media Resources > MOH Audio File Management and upload your audio file. Wait until the file status shows that conversion has finished. In many releases, files must be uploaded separately on every node that runs the streaming service; confirm this for your version.
• 3. Go to Media Resources > Music On Hold Audio Source. Add a new source, or edit an existing one. Give it a recognizable name, select the uploaded file, and choose whether it should play continuously.
• 4. Make sure phones can reach the MOH server. Add the server to a Media Resource Group, add that group to a Media Resource Group List, and assign the list to the device pool or to the devices that put callers on hold.
• 5. Assign the audio source. User Hold MOH Audio Source applies when someone presses Hold. Network Hold MOH Audio Source applies to transfers, conferences and call park. Both can be set on the device pool, the phone or the directory number, and the more specific setting normally takes priority. The clusterwide defaults are set in service parameters.
• 6. Save, then apply the configuration or reset devices where prompted. Device pool changes can require resetting phones, so schedule them for a quiet period.

Version differences: newer releases add options such as initial and periodic announcements, and field names and page layouts change between versions. If a page in these steps does not match your screen, look up the MOH section of the administration guide for your exact release rather than guessing.

Cisco Unified CME

• 1. Copy the audio file to router flash, for example with copy tftp: flash: and the server address and file name when prompted.
• 2. Enter global configuration mode, then enter telephony-service.
• 3. Point MOH at the new file with moh followed by the file name stored in flash.
• 4. Configure multicast MOH with the multicast moh command only if your design needs it, for example to supply hold music to other devices. Multicast traffic must be routable to those devices.
• 5. Save the configuration with write memory. To revert, run the moh command again with the previous file name you noted.

Check the output

Place a test call from an outside line or another phone, and have the answering user press Hold. Then test a transfer and a call park, because these use the network hold source rather than the user hold source. If you have several sites or codec regions, test a call that crosses them.

• Music plays instead of beeps or silence.
• The correct file plays. If an older file plays, a source assigned at a more specific level is likely taking priority.
• Sound quality is acceptable for telephony. Hold music travels through narrowband voice codecs such as G.711 or G.729, so it will never sound like the original recording, and speech-oriented codecs can distort music noticeably.
• Volume is close to normal conversation level. If it is too loud or too quiet, adjust the file in an audio editor and upload it again.

On CME you can also confirm the setup from the CLI: show flash: lists the stored file, and show running-config | section telephony-service shows which file the moh command points to.

Common problems and next steps

• Callers hear beeps instead of music: the phone could not obtain an MOH resource and fell back to tone on hold. Check that the streaming service is running and that the MOH server is in the media resource group list used by that device. Also confirm the region settings allow a codec the MOH server offers.
• Callers hear silence: common causes are a codec or region mismatch, a firewall or NAT blocking the audio stream, or multicast MOH configured on a network that does not route multicast.
• The default or old music still plays: check the directory number and phone settings for an overriding source. On CUCM, also confirm the file exists on the node that actually serves the call.
• The upload is rejected: the file format is not supported. Convert it to a supported format and upload it again.
• Music sounds harsh or distorted: export a clean mono version without heavy bass or extreme loudness processing, then retest with the codec your calls actually use.
• CME cannot find the file: check that the name in the moh command matches the file in flash exactly, including case and extension.

Once hold music works, consider separate audio sources for different sites or departments, and record which source is assigned at each level. That record makes later changes and troubleshooting much faster.