An Enhanced Port Forwarding (EPF) solution for NAT traversal in 3GPP Machine Type Communications

Recently, the key issues of Machine-to-Machine (M2M) communications also known as Machine Type Communications (MTC) are widely discussed in 3^rd Generation Partnership Project (3GPP). One of the key issues for MTC is the IP addressing issue. IPv6 address space is preferred to use in MTC. However, the private IPv4 addresses are used for current configurations. Thus, the Network Address Translation (NAT) traversal problem should be resolved for MTC in 3GPP architecture. In this paper, we introduce the architectures and call flows of three NAT traversal solutions defined in 3GPP 23.888. Those are the NAT Traversal through Tunneling (NATTT) solution, the Managed NAT solution and the Non-managed NAT solution. Then we propose an Enhanced Port Forwarding (EPF) solution to minimize the impacts on the MTC device and 3GPP core network. Finally, we analyze and compare the proposed EPF solution with the existing solutions.