Music on Hold

Music on hold (MoH) is recorded music that callers listen to while waiting on hold. It is used to avoid silence on the line and is used in several places of the system: when a call is on hold and when a caller is waiting in an agent group queue. The system allows three different source types for its music on hold: file, wave input, and RTP stream. These sources serve different purposes and are detailed below. The sources can be used in parallel in different locations on the same system. They can be assigned to different domains or all domains so that they can appear as moh options in those domains.

• Files: The system can use one or more files for MoH. These files are read by the system on demand and are played in an endless loop. Files must be placed manually into the audio_moh directory of the system. Although files are loaded only once, long files will be read into memory and can consume a lot memory space. Keep in mind that each minute of the file will require about 1 MB of memory space, so a 7-minute file will take up about 6.7 MB (128 kbit/s * 7 * 60 seconds). After it gets past the initial hick-up (jitter), subsequent calls to the MoH file will be smooth. Format: Files must be in 8-kHz sampling frequency, and they should be in 16 bit per sample signed format. The format must be mono WAV. You may also use other formats (u-law and GSM), but these formats will have less audio quality and require more CPU performance.
• Wave input: In Windows, the Vodia pbx can read MoH from an audio input jack, which is a convenient way to connect a CD, MP3 player, or a radio to the system. The disadvantage of this method is that only one external music source can be used. You can also internally loop the audio output of the local computer back to the audio input of the computer. This allows you to use an MP3 player running locally to provide a large number of MP3 files. However, we recommend keeping an eye on the memory usage of the MP3 player, as some players have memory leaks and slowly consume the memory of the computer. MP3 and WAV files can be converted to the required format. Note: This feature is currently available only for Microsoft Windows-based operating systems. The appliance uses the RTP streaming mode for the audio input jack.
• RTP stream: Streaming RTP data is a popular way of providing music from external sources. As with a telephone conversation, the system receives the audio data in a standard RTP stream. Several external tools are available that are able to generate a compliant RTP stream. Because the system can have several RTP streams, you can use this method to generate different music on hold sources for the system. Format: The RTP stream must use G.711 encoding. No SIP signalling is involved with this method, and the system does not send RTP data back. Important: Be sure to specify the port on which the system should listen for RTP input (e.g., 42000). This port must be available on the system. If you change the setting, you might need to restart the system service so that the change takes effect.

List of available sources

The table shows the following columns:

Name: The name of the source.

Type: The type as described above.

Value: For files, a play button can be used to preview the source.

Position: The position for the file (see below).

Tenant: If the source was assigned to a specific tenant, the name will show here.

Volume: The volume for the source.

Adding Music on Hold

When adding a MoH source, the following fields are available:

Name: The name of the MoH source, for example "Rock Music".

Type: From the dropdown, choose the type of MoH that you will be using.

• File: The source is an audio file (see below).
• RTP Stream: The music is read from a live audio stream.
• WAV Input: This option is available on Windows PC that have an analog audio input. Volume: The volume of the music. Position: When the system starts playing back music from a file, this setting determines the position within the file. The following options are available:
• All calls share the same position: This mode emulates the continuos playback of the file, no matter how many calls are actually using the file. This is useful when a caller is put on hold multiple times during a call and the file has a significant length, so that the caller gets the impression that the file continued playing while speaking to an agent.
• Always from the beginning: This mode will start the file always from the beginning. This mode is suitable for short files with no end or beginning.
• Remember last position: This mode will play the file from the last position. Tenant: The source can be limited to a specific tenant. Filename: The PBX plays back WAV files with 8 kHz sampling frequency and linear mono encoding. When using a file that does not conform to this format (e.g. MP3), the PBX will concert the file into the correct format automatically (PBX version 69.3.1 or higher). Port Number: When using the RTP stream mode, this port number will be opened on the PBX server (this will require a restart of the PBX service). Codec: The codec that is expected on the RTP port. Key 0-9: Depending on the context, callers can use their DTMF keypad to perform certain actions. These actions include:
• Redirect to number: The system will redirect the caller to the provided number.
• Send text message to caller: This will trigger sending a message to the caller, using the SMS provider and policy setup for the account.
• Trigger HTTP GET to URL: This will trigger a HTTP get from the PBX web client. The following parameters are available inside the URL:

Name	Value
{from}	The caller-ID of the caller
{to}	The caller-ID of the callee
{remote}	The caller-ID of the remote party (caller for inbound calls, callee for outbound calls)
{local}	The caller-ID of the local party
{inbound}	true for inbound calls, false for outbound calls
{cnam}	The display name of the caller
{account}	The account name for the local partx
{domain}	The DNS name of the tenant