If you want callers to hear music when a Mobile Agent places the caller on hold, you must assign Music on Hold (MoH) resources to the ingress voice gateway or trunk that is connected to the caller (as you do with traditional agents). In this case, the user or network audio source is specified on the local CTI port configuration. Similarly, if a Mobile Agent must hear music when the system puts the agent on hold, you must assign MoH resources to the ingress voice gateway or trunk that is connected to the Mobile Agent. In this case, the user or network audio source is specified on the remote CTI port configuration.
Cisco recommends that you not assign MoH resources to local ports and remote CTI ports, because it might affect the system performance. If you have Agent Greeting for Mobile Agents, Cisco strongly recommends that you do not assign MoH resources to local and remote CTI ports.
If a remote Mobile Agent calls over a nailed connection and if there is no active call to the agent, the agent is put on hold. In general, Cisco recommends that you enable MoH to the Mobile Agent phone for nailed connection calls. If MoH resources are an issue, consider multicast MoH services.
If a remote Mobile Agent calls over a nailed connection, and if MoH is disabled, the hold tone plays to the agent phone during the hold time. This depends on the call processing agent that controls the Mobile Agent remote phone. For Unified CM, the hold tone is enabled by default (it is similar to the Mobile Agent connect tone). Because the hold tone is similar to the connect tone, it is difficult for the agent to identify if a call arrived from listening to the Mobile Agent connect tone. The hold tone prevents the agent from hearing the connect tone.
Therefore, Cisco recommends that you disable the hold tone by changing the setting of the Tone on Hold Timer service parameter to 0. For more information about setting this parameter, see the Unified CM product documentation available at: http://www.cisco.com/en/US/products/sw/voicesw/ps556/tsd_products_support_series_home.html.