Methods and systems are disclosed to enable a smart card having relatively low data rate and low computational power to control a high data rate communications channel without degradation of performance. The smart card and an associated monitor/interface, which can be implemented in a network access device, are interposed between transmitting and receiving nodes in a network, and configured to intervene when conditions of rules stored in the smart card are met. For example, the smart card can intervene when a packet header indicates sufficient change in information, such as the exceeding of a predefined threshold or a requirement for user authorization/authentication. In one mode of regulating packet flow, the smart card selectively enables or disables packet transmission, reception, or both, according to the rules stored therein. In another mode, the smart card, upon activation, provides rules and modifications for packet data, headers, or both. The rules and modifications can implement communication policies of the entity providing communication services to the user of the services, and can be stored in the smart card to prevent alteration or tampering.