a wireless network gateway for transmitting data between a wireless network and a packet data network . the wireless network gateway comprises : 1 ) n input - output processors for transmitting and receiving data packets to and from the wireless network and the packet data network ; 2 ) m service processors for performing packet data serving node functions associated with data sessions between the packet data network and mobile stations communicating with the wireless network ; 3 ) a switch fabric for the n input - output processors and the m service processors ; and 4 ) p switch modules . each of the p switch modules transfers data packets between the switch fabric and at least one input - output processors . a first switch module stores session bindings information associated with a first data session between a first mobile station and the packet data network .