The present disclosure provides a method and apparatus to initiate a session with a packet gateway for a connecting device configured to authenticate with a subscribing wireless device’s authentication information. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing ABCG4 transporter nucleic acid molecules, host cells into which the expression vectors have been introduced, and non-human transgenic animals in which an ABCG4 transporter gene has been introduced or disrupted. If the VC is determined to be inactive, a number of memory buffers initially allocated to the inactive channel is determined, and the memory buffers are re-allocated between the active VCs.