The devices registered in the Multi-Device Access (MDA) group, inherit the properties of the extension configured on Communication Manager. However, the support of the feature buttons differ from one device to another.

When one of the MDA devices answers the incoming call, Session Manager cancels the call request to other MDA devices. The inactive devices can join the call by using the Simulated Bridged Appearance (SBA) feature. However, Communication Manager does not change the call display to conference. The MDA devices display the call as a two-party call. This feature of joining a call is known as Multi-Device Access.

When all the MDA devices receive a call, only one device can answer the call. However, multiple MDA devices can send a provisional response about sending early media, for example, a ringback or an announcement.

The Hold and Active states are managed for all the registered devices irrespective of whether the devices are active or idle. For example, when one of the MDA devices places the call on hold, the call remains in the active state till other MDA devices active on the call also change the call state to hold.

If an MDA device is active on a call and tries to join the call by using one of the other MDA devices, Communication Manager checks the status of the Exclusion feature setting. If the feature is active, the devices cannot join the call until the exclusion feature is deactivated by the MDA device user who activated it.