Methods and apparatus are disclosed for changing the bandwidth or other traffic characteristic of an established packet call in response to an identification of the requirements of the call. In one implementation, an integrated access device (“IAD”) is used to connect one or more devices to a packet network. When a device goes off-hook, a call is established through the packet network with an initial bandwidth, such as that which will support a compressed and silence suppressed voice call. The IAD monitors the received signal to determine whether a type of traffic is detected which requires a different call characterization. A request may be made to modify the traffic characterization of the established call to match the detected call characterization. In an ATM network, Q.9231.x may be used to request a change in the bandwidth of the originally established call.