A stream request is generated based on the stream address of a corresponding program selected from an electronic program guide that associates programs with corresponding IP multicast stream addresses by a subscriber/user device. The stream request is sent from the subscriber device to a broadband device, which compares the address in the request to available stream information listed in a content guide. The content guide contains information for all multicast streams that are available from a CMTS to the broadband device over DS channels of the current MAC domain. The broadband device locks to the stream that corresponds to the request, including tuning to a different DS channel if necessary. The broadband device may request another MAC domain if the stream is not available from the current one. After locking to a desired stream, the broadband device informs the CMTS so that it can adjust content guide user counts.