1. A method for establishing a communication session between a user in a telecommunications network and a remote party, the method comprising: transmitting, at a communication session control system located in a signaling path for the communication session, a communication session establishment request, wherein the communication session establishment request includes a request to a given communication client, of a plurality of communication clients, to place the given communication client in a prior-to-answer session state, wherein the given communication client is on one of one or more user devices at which the user may accept the communication session establishment request and conduct voice communications with the remote party, and wherein the remote party is associated with a remote device; receiving, in response to transmitting the communication session establishment request, a communication session hold response message from the given communication client, the communication session hold response message requesting that a communication session with the remote device be established initially in an on-hold state and that an option to retrieve the on-hold communication session be made available to at least one communication client of the plurality of communication clients other than the given communication client, wherein the at least one other communication client is on one of the one or more user devices at which the user may participate in the communication session; determining, based on said communication session hold response message received from the given communication client, that the option to retrieve the on-hold communication session is to be made available to the at least one other communication clients; and transmitting notification data to the at least one other communication client to notify the at least one other communication client that the on-hold communication session is available for retrieval by the at least one other communication client.