A network node apparatus is disclosed for the capture, storage and replay of video data at separate respective nodes of a communications network arranged to operably couple the node apparatus. The node apparatus may include a video capture node operable to capture video data and to transmit captured data via the communications network to a video storage node. The video storage node is arranged to store captured video data, and to transmit stored data via the communications network to a video replay node which renders an image therefrom. The video storage node transmits video data to the video replay node only if the content of a transmit buffer therein matches or exceeds a predetermined lower content value and the content of a receive buffer in the replay node does not exceed a predetermined upper content value.