Comparing radio-to-router interface implementations on experimental CoTs and open source routers

In highly dynamic wireless environments, link metrics such as link quality, availability, and others have become increasingly important to enable smart multi-hop routing decisions. In recent years, a number of radio-to-router interface (R2RI) protocols such as Point-to-Point over Ethernet RFC5578, Dynamic Link Exchange Protocol (DLEP), and Radio-Router Control Protocol (R2CP) have emerged to address the need to have a common set of link metrics exposed from the radio to the router to enhance multi-hop routing decisions. To fully evaluate R2RI functionality and specifications, differing implementations of both radio/client and router/server-side R2RI protocols must be prototyped and tested. In this paper, we present comparison tests of each of the three (3) radio-to-router interfaces with two (2) router/server-side R2RI experimental/beta R2RI implementations: one on a commercial Cisco router, and one on an open source Quagga platform. The goal of the comparison is not necessarily to provide a holistic performance comparison (as much of the code is experimental), but to highlight implementation differences and potential issues. In many cases, issues are already resolved in future releases.¹