Tunnel Congestion Exposure and Feedback

摘要

Tunneling technology has been widely applied in the network, but the lack of effective congestion exposure in the tunnel, seriously affect the performance of the tunnel technology. This document will focus on the tunnel scenario, to design a tunnel congestion exposure and feedback model, and the tunnel congestion marking scheme and congestion information feedback scheme. First, the document describes Tunneling Protocol, Secondly describes the congestion problems in the tunnel, Thirdly proposes a basic tunnel congestion exposure model, Finally, proposes the detail of tunnel congestion marking and feedback scheme for the model. Modifying the ECN tunnel rules of RFC3168 and RFC6040, congestion marking scheme can be applied to the feedback model. Congestion feedback scheme use GRE (Generic Routing Encapsulation) header format extension to carry the feedback information. Content and format of Congestion feedback, and the transmission of feedback information are also discussed in the document.