Techniques for efficiently allocating ports and bandwidth in a communication system configured to establish interactive, real time communication sessions between endpoints are described. Requests are received at a server, from a requester endpoint device, to initiate an interactive, real time communication voice and/or video session requiring access to an interactive session resource. In an embodiment, the communication system is a contact center and the interactive session resource is an available contact center agent. Pending availability of the interactive session resource, a requester is assigned a place in a queue or otherwise scheduled to receive access to the interactive session resource. In the meantime, a data channel is established between the server and the requester's endpoint device. Resources, which can include an executable program and/or information operative to enable the endpoint device to emulate an active on-hold voice connection period, are downloaded to the endpoint device.