A service gateway includes a fast path module for processing data packets without using packet buffers and a normal path module for processing data packets using packet buffers. The fast path module receives a service request data packet from a client side session, determines that the service request data packet cannot be processed by the fast path module, and in response, sends the service request data packet to the normal path module. After receiving the service request data packet, the normal path module retrieves a first proxy session record created by the fast path module, where the first proxy session record is associated with a client session record for the client side session, creates a second proxy session record based on the service request data packet and the client session record, and processes the service request data packet according to the second proxy session record.