APOHN: subnetwork layering to improve TCP performance over heterogeneous paths

This paper proposes a novel architecture, named APOHN, designed for data communications over heterogeneous networks. APOHN enables easy implementation of various existing and upcoming performance optimization solutions with the main objective to keep the standardized TCP/IP reference model untouched. APOHN architecture extends ISO/OSI protocol stack model with an additional layer designed for subnetwork communications and optimized with specific physical subnetwork characteristics in mind. TCP/IP flow speedup, subnetwork flow multiplexing and optimized subnetwork communications result in great performance improvements in heterogeneous networks. Moreover, the support of IPsec enables secure communications. APOHN performance is evaluated through simulations using a combined satellite and WLAN network scenario-commonly used in disaster recovery as well as in a variety of military applications. APOHN constitutes an architectural solution competitive with leading architectures such as performance enhancement proxies (PEP) as well as delay-tolerant networking (DTN)