The present invention allows a first communication client, which is initiating a communication session, to include admission information in a session request used to establish the communication session in a regular call or conference scenario. The session request is intended to trigger a communication session between the first communication client and another communication client, which is associated with a telephony endpoint or a conferencing system having a communication client. The receiving communication client will use the admission information provided in the session request to determine whether the session is authorized. If authorized, the receiving communication client will either establish the communication session or allow the communication session to be established, as the situation dictates.