What does Call Admission Control require the client to send in order to reserve the bandwidth?

SIP (Session Initiation Protocol) flow information is used for signaling and establishing calls, but it does not directly contain the detailed bandwidth reservation request required by CAC for admission decisions.

Wi-Fi Multimedia (WMM) is a QoS standard for Wi-Fi networks that defines access categories, but it is the framework that utilizes TSPEC for bandwidth requests, not the request itself.

VoIP media session awareness is a general concept that the network understands VoIP traffic, but it is not a specific message or information sent by the client to reserve bandwidth for CAC.

Call Admission Control (CAC) mechanisms, especially in wireless networks (e.g., using WMM-AC), rely on clients sending a Traffic Specification (TSPEC) to the access point. This TSPEC conveys the bandwidth and QoS requirements for the upcoming voice or video call, allowing the network to decide if enough resources are available before admitting the call.