Traffic Management for TCP/IP over Satellite-ATM Networks

Several Ka-band satellite systems have been proposed that will use ATM technology to seamlessly transport Internet traffic. The ATM UBR, GFR and ABR service categories have been designed for data. However, several studies have reported poor TCP performance over satellite-ATM networks. We describe techniques to improve TCP performance over satellite-ATM networks. We first discuss the various design options available for TCP end-systems, IP-ATM edge devices as well as ATM switches for long latency connections. We discuss buffer management policies, guaranteed rate services, and the virtual source/virtual destination option in ATM. We present a comparison of ATM service categories for TCP transport over satellite links. The main goal of this paper is to discuss design and performance issues for the transport of TCP over UBR, GFR and ABR services for satellite-ATM networks. 1 This work was partially supported by the NASA Lewis Research Center. Rohit Goyal, Raj Jain, Sastri Kota, Mukul Goyal, Sonia Fahmy, Bobby Vandalore a). The Ohio State University b). Lockheed Martin Telecommunications