A method comprising: registering a plurality of on-premises media agents (111, 112, 113) with a controller, the plurality of on-premises media agents (111, 112, 113) disposed at a physical location of an enterprise; registering a plurality of other media agents (121, 122, 123) with the controller; receiving from a client device a message requesting to join a conference at the controller; and selecting by the controller at least one on-premises media agent or at least one other media agent to handle the message requesting to join depending upon at least one factor associated with the conference that the client device is requesting to join, characterised in that the controller is a cloud-based controller disposed at a cloud location that is remote from the physical location of the enterprise, the plurality of other media agents (121, 122, 123) is a plurality of cloud-based media agents disposed at the cloud location that is remote from the physical location of the enterprise and wherein the at least one factor comprises one or more of: a location of the client device, such that on-premises media agents are selected for on-premises client devices and cloud-based media agents are selected for client devices that are not on-premises of the enterprise; a security type of the conference, such that secure conferences are directed to on-premises media agents when the on-premises media agents are deemed to be more secure than the cloud-based media agents or are directed to cloud-based media agents (121, 122, 123) when the cloud-based media agents are deemed to be more secure than the on-premises media agents; and a media type of the conference, such that conferences of a first media type are directed to on-premises media agents and conferences of a second media type are directed to cloud-based media agents (121, 122, 123). registering a plurality of on-premises media agents (111, 112, 113) with a controller, the plurality of on-premises media agents (111, 112, 113) disposed at a physical location of an enterprise; registering a plurality of other media agents (121, 122, 123) with the controller; receiving from a client device a message requesting to join a conference at the controller; and selecting by the controller at least one on-premises media agent or at least one other media agent to handle the message requesting to join depending upon at least one factor associated with the conference that the client device is requesting to join, characterised in that the controller is a cloud-based controller disposed at a cloud location that is remote from the physical location of the enterprise, the plurality of other media agents (121, 122, 123) is a plurality of cloud-based media agents disposed at the cloud location that is remote from the physical location of the enterprise and wherein the at least one factor comprises one or more of: a location of the client device, such that on-premises media agents are selected for on-premises client devices and cloud-based media agents are selected for client devices that are not on-premises of the enterprise; a security type of the conference, such that secure conferences are directed to on-premises media agents when the on-premises media agents are deemed to be more secure than the cloud-based media agents or are directed to cloud-based media agents (121, 122, 123) when the cloud-based media agents are deemed to be more secure than the on-premises media agents; and a media type of the conference, such that conferences of a first media type are directed to on-premises media agents and conferences of a second media type are directed to cloud-based media agents (121, 122, 123). a location of the client device, such that on-premises media agents are selected for on-premises client devices and cloud-based media agents are selected for client devices that are not on-premises of the enterprise; a security type of the conference, such that secure conferences are directed to on-premises media agents when the on-premises media agents are deemed to be more secure than the cloud-based media agents or are directed to cloud-based media agents (121, 122, 123) when the cloud-based media agents are deemed to be more secure than the on-premises media agents; and a media type of the conference, such that conferences of a first media type are directed to on-premises media agents and conferences of a second media type are directed to cloud-based media agents (121, 122, 123).