This paper proposes a mechanism for equation-based congestion control for unicast traffic. The dominant transport protocol in the Internet is TCP, which uses an Additive Increase Multiplicative Decrease (AIMD) algorithm. However, for real-time applications, halving the sending rate in response to a single packet drop can be too severe. Equation-based congestion control uses a control equation that explicitly gives the maximum acceptable sending rate as a function of the recent loss event rate. The sender adapts its sending rate based on feedback from the receiver. For traffic competing with TCP in the best-effort Internet, the appropriate control equation is the TCP response function characterizing the steady-state sending rate as a function of round-trip time and steady-state loss event rate. The paper introduces the TCP-Friendly Rate Control (TFRC) protocol for equation-based congestion control. TFRC provides a more smoothly-changing sending rate compared to TCP, which can be beneficial for applications that need to maintain a slowly-changing sending rate while being responsive to network congestion over longer time periods. TFRC is designed to be more suitable for unicast streaming multimedia applications than TCP. The algorithm for calculating the loss event rate is a key design issue in equation-based congestion control, determining the tradeoffs between responsiveness to changes in congestion and the avoidance of oscillations or unnecessarily abrupt shifts in the sending rate. The paper discusses the design of TFRC, including the calculation of the loss event rate, the use of the TCP response function, and the handling of different types of congestion. It also addresses the issue of how to increase the sending rate when the rate given by the control equation is greater than the current sending rate. The paper also discusses the response of TFRC to persistent congestion and quiescent senders. The paper presents experimental results showing that TFRC performs well in comparison to TCP in various network conditions. It demonstrates that TFRC is remarkably fair when competing with TCP traffic, and that it behaves well across a wide range of network conditions. The paper also discusses the effects of TFRC on queue dynamics, showing that TFRC traffic does not have a negative impact on queue dynamics in this case. The paper concludes that TFRC is a viable mechanism for providing relatively smooth congestion control for unicast traffic.This paper proposes a mechanism for equation-based congestion control for unicast traffic. The dominant transport protocol in the Internet is TCP, which uses an Additive Increase Multiplicative Decrease (AIMD) algorithm. However, for real-time applications, halving the sending rate in response to a single packet drop can be too severe. Equation-based congestion control uses a control equation that explicitly gives the maximum acceptable sending rate as a function of the recent loss event rate. The sender adapts its sending rate based on feedback from the receiver. For traffic competing with TCP in the best-effort Internet, the appropriate control equation is the TCP response function characterizing the steady-state sending rate as a function of round-trip time and steady-state loss event rate. The paper introduces the TCP-Friendly Rate Control (TFRC) protocol for equation-based congestion control. TFRC provides a more smoothly-changing sending rate compared to TCP, which can be beneficial for applications that need to maintain a slowly-changing sending rate while being responsive to network congestion over longer time periods. TFRC is designed to be more suitable for unicast streaming multimedia applications than TCP. The algorithm for calculating the loss event rate is a key design issue in equation-based congestion control, determining the tradeoffs between responsiveness to changes in congestion and the avoidance of oscillations or unnecessarily abrupt shifts in the sending rate. The paper discusses the design of TFRC, including the calculation of the loss event rate, the use of the TCP response function, and the handling of different types of congestion. It also addresses the issue of how to increase the sending rate when the rate given by the control equation is greater than the current sending rate. The paper also discusses the response of TFRC to persistent congestion and quiescent senders. The paper presents experimental results showing that TFRC performs well in comparison to TCP in various network conditions. It demonstrates that TFRC is remarkably fair when competing with TCP traffic, and that it behaves well across a wide range of network conditions. The paper also discusses the effects of TFRC on queue dynamics, showing that TFRC traffic does not have a negative impact on queue dynamics in this case. The paper concludes that TFRC is a viable mechanism for providing relatively smooth congestion control for unicast traffic.