/mcpProcedure Step 1 In Cisco Unified CM Administration, choose Media Resources > MOH Audio File Management. The Music On Hold Audio File Management window appears. Step 2 View the following information for each record: • Check box—If the audio file can be deleted, a check box appears before the File Name column. • File Name—This column displays the audio file name. • Length—This column displays the audio file length in minutes and seconds. • File Status—This column displays one of the following statuses of an audio file: • Translation Complete—This status appears after a file is uploaded successfully and is available for use as audio files for a music on hold audio source. • In Use—This status appears after you add a Music On Hold audio source that uses this audio file as its MOH audio source file. Note You cannot a delete a file with In Use status. Unicast and Multicast Audio Sources Unicast Music On Hold is the system default option. However, you need to configure for multicast, if required. Both multicast and unicast configurations present the same audio-source behavior to held parties. Each audio source is used once, and the stream is split internally and is sent to the held parties. The only difference between multicast and unicast, in this case, is how the data is sent over the network. Table 59: Differences Between Unicast and Multicast Audio Sources Multicast Audio Source Unicast Audio Source Consists of streams that are sent from the MOH server to a multicast group IP address. Endpoints that request an MOH audio stream can join multicast MOH, as needed. Consists of streams that are sent directly from the MOH server to the endpoint that requests an MOH audio stream. A multicast MOH stream is a point-to-multipoint, one-way audio RTP stream between the MOH server and the multicast group IP address. A unicast MOH stream is a point-to-point, one-way audio RTP stream between the server and the endpoint device. Enables multiple users to use the same audio source stream to provide MOH. Unicast MOH uses a separate source stream for each user or connection. As more endpoint devices go on hold through a user or network event, the number of MOH streams increases. Feature Configuration Guide for Cisco Unified Communications Manager, Release 15 and SUs 627 Custom Features Unicast and Multicast Audio Sources