Congestion in today's mobile networks is mainly managed by end to end congestion control algorithms such as TCP. However, in spite of its many merits, TCP does not cope well with the high variability inherent to radio links and customer experience may sometimes be poor as TCP reveals unable to rapidly grasp such a fluctuating bandwidth. To remedy this problem, we introduce in this paper a new proposal called SloMo. Contrary to existing mechanisms, SloMo does not rely on protocol analysis and may be applied to encrypted traffic. SloMo is particularly easy to implement and deploy, robust to encryption, and its performance evaluation is quite encouraging.