A packet-based video network includes: plural packetized video data nodes; a packet switch configured to switch from one of video packet routes to another of video packet routes; and a video synchronizer configured to synchronize the video frame periods of at least nodes acting as packetized video data sources; wherein: each node acting as a packetized video data source is configured to launch onto the network packetized video data such that, for at least video frame periods adjacent to a switching operation: the node launches onto the network packetized video data required for decoding that frame during a predetermined active video data portion of the video frame period, and the node does not launch onto the network packetized video data required for decoding that frame during a predetermined remaining portion of the video frame period; and the switching operation is implemented during the predetermined remaining portion.