The invention relates to a method and an arrangement for optimizing a link latency on a communication interface in a communication network comprising a first communication network node (18) and a second communication network node (16) communicating with said first communication network node (18) on said communication interface and sending framed data packets having frame numbers to a plurality of user equipments over a radio interface. A transmission delay on said communication interface is measured and downlink data having an adjusted frame number based on said measured transmission delay is requested.