Method and apparatus for a fast installation of an IP user connection over a 3GPP Nb interface under application of the BICC 'delayed backward bearer establishment' and avoidance of failure

Establishing an IP user data transport connection between a Media Gateway O and a Media Gateway T, wherein the user data transport connection is established according to the BICC "Delayed Backward Bearer Establishment". Upon receipt of an IPBCP Request message from MGW T, MGW O sends an IPBCP Accepted message towards MGW T and starts sending data within the user data transport connection towards MGW T. It is probable that the user data arrive at MGW T before the IPBCP accepted message. MGW T retrieves the source IP address and Port number from a received user data transport connection IP packet from MGW O and MGW T sends upon receipt of a user data transport connection IP packet from MGW O the first user data transport connection IP packet(s) towards MGW O, using the retrieved IP Address and Port number as destination.