This article presents an overview of standards and a survey of recent work on QoS control of next generation networks (NGNs). We outline primarily standardized QoS control architectures with respect to the service and transport strata of NGN. In the service stratum, QoS parameter negotiation using core IMS procedures is described. In the transport stratum, the resource control and admission schemes of IMS (3GPP), RACF (ITU-T), and RACS (ETSI/ TISPAN) are explained and compared with each other in terms of QoS coverage and number of required signaling messages. In addition, we give a survey of papers on QoS control architectures, which further strengthen existing standards by adaptively managing QoS modification according to user's QoS changes and consistent QoS support for mobile users. Finally, we conclude this article with a discussion of further work of the QoS control for NGN.