NDN-trace: a path tracing utility for named data networking

In this paper we propose NDN-Trace, a path tracing utility to determine the characteristics of the available paths to reach a given name prefix in NDN-based networks. While the traceroute tool in IP networks is based on an iterative process, with each iteration incrementally traversing more hops along the path to the target, we adopt a non-iterative approach, with the tracing process done at the application layer. Our design supports multi-path tracing that can be used to trace paths to NDN forwarding nodes, applications, or content store caches, while providing path information (node identifiers and round-trip times), as well as optional metrics such as those related to content stores. NDN-Trace leverages NDN's native Interest/Data exchange and does not require changes to NDN forwarding. We present a C++ implementation of our design, and show experimental results that demonstrate its capabilities. We also discuss open issues and future work, including an approach to implement path tracing within the NDN forwarder itself.