The FCC solution requires the STB to switch from unicast to multicast after the fast channel change completes. The STB uses IGMP to switch to multicast. In some cases, the multicast process is delayed. Delay may occur because of IGMP processing delay, authentication delay, or network delay. The extended-unicast command, which is used for CDN for Live TV, delays the IGMP for up to 5 minutes. Nokia recommends enabling this command only in implementations where multicast delivery is delayed beyond 1.5 seconds. By default, extended unicast is disabled to ensure the optimal bandwidth for unicast to multicast handover.