This paper presents an efficient and accurate available bandwidth estimation algorithm for satellite links which generally have long propagation delay. Either the method using the rate of returning ACKs or the method using timestamp option is adopted for the bandwidth estimation algorithms to enhance TCP performance in the literature. The method using the rate of returning ACKs, which is the most popular for the available bandwidth estimation for a TCP connection, is known to have the influences from the reverse link (TCP receiver to TCP sender) traffic variation, especially in the asymmetric satellite links. The bandwidth estimation method using packet sending time information from the TCP timestamp option also has the drawback that the influence of the bottleneck link presented in the forward path is not properly considered. To overcome these limits, our algorithm performs in two steps. A forward path delay is calculated at the sender with the receiver sending time for an ACK packet in the first step. And in the second step, the forward path delay is updated more delicately through removing unrelated part from the forward path delay, and is applied for available bandwidth estimation. The simulation results show that our algorithm can avoid the influence of the traffic variation in the return path (e.g., ACK compression, DAMA delay), and estimate the available bandwidth over the forward path more accurately. Satellite networks are becoming the important candidate in information and communication infrastructures because they provide several advantages to the wireless Internet communications. They generally provide wider coverage, higher bandwidth, and relatively faster establishment than other terrestrial wireless networks. Nevertheless, satellite links pose some challenges to the congestion control operation of the TCP (Transmission Control Protocol) (10). Main challenges of the satellite networks to the TCP performance are the long RTT (round-trip time) which is generally around 600msec in the bi-directional networks over the geostationary satellite, and the presence of the high packet loss rate by wireless random error which causes congestion control of the TCP spuriously. To solve the problems while keeping end-to-end semantics of TCP, an accurate bandwidth estimation algorithm is