The objective of this paper is to explain QOS usage on PacketCableTM, a cable-industry project aimed at identifying, qualifying, and supporting internet protocol based voice and video products over cable systems. PacketCable uses the Data Over Cable Service Interface Specification (DOCSIS) another cable industry initiative as the underlying platform in its overall architecture. Traditional cable networks are built to provide one-way broadcast services with audio-visual content and limited data. In this present model, the extent to which quality-of- service (QOS) can be used is very restricted. The industry trend is migrating towards providing two-way interactive audio, video, and data services over the cable network. Therefore QOS is becoming an instrumental and inseparable aspect of delivering superior services to consumers. Since PacketCable uses the underlying DOCSIS QOS parameters to establish QOS flows, this paper discusses the linkages between these two protocols.