Frames received at a redundant port connecting a node to a communications network are identified by the frames including a sequence number associated with a source. A frame is received at the redundant port from a source. A newest sequence number of frames received from the source at the node is determined. A window of frames from the source is determined by corresponding sequence numbers. The window includes sequence numbers preceding the newest sequence number and associated with reception information of a corresponding frame at the node. The node relays the frame, when a sequence number of the received frame is within the window and the reception information indicates a first reception of the frame at the node.