Example embodiments provide methods for handling the transition of a mobile device from a first network to a second network, the second network operating according to a different communications protocol from the first network. One example embodiment includes terminating forwarding of the data packets from the first network to the mobile device; rebuilding headers of unforwarded data packets at the first network; and sending the rebuilt data packets from the first network to the second network. Another example embodiment includes resetting a header compression state at the second network; receiving unforwarded data packets from the first network at the second network, the unforwarded data packets being data packets the first network had not yet forwarded to the mobile device; and sending the unforwarded data packets from the second network to the mobile device.