With the advancement of technology and evolution of heterogeneous access networks, mobile devices are equipped with multiple network interfaces. Usually these mobile devices use single access network for communication, hence in case of node's mobility across heterogeneous networks this single network interface based communication results in higher handover delay and service disruption time. As today's mobile devices are multi-homed, and coverage area of different access networks usually overlap, hence mobile devices may have more than one active network interfaces. These active interfaces can be used simultaneously for communication. In this paper, we have discussed the effectiveness of multi-homing and parallel transmission during and after the vertical handover process. Results show that through the use of multi-homing and parallel transmission, handover delay and service disruption time can be reduced significantly and throughput can be increased.