This object limits how many multicast streams can be active at once on a single DSL subscriber connection (UNI), with a special value of zero meaning the limit is ignored when the system decides whether to allow a channel-change request. This matters because most households only have one or two screens active at a time, so capping simultaneous streams prevents a subscriber's set-top boxes from requesting more concurrent channels than the line or CPE can actually decode. A triple-play subscriber with two set-top boxes might have maxMulticastStreams set to 2, so a request for a third simultaneous stream would be rejected by the OLT/ONU.