Routing in Fat Trees: a protocol analyzer for debugging and experimentation

In the last decade, the Internet has been experiencing a gradual transition from a hierarchical network of networks to a content-driven network. This refactoring of the Internet's architecture is heavily based on the deployment of massive data centers whose basic services are computing, storage, and replication. This type of data centers may scale up to hundreds of thousands of servers, therefore, demanding a communication scale and bandwidth much higher than the historical Internet WAN traffic. Specific data center routing and forwarding solutions are needed to cope with the stringent communication requirements in this context. We are experimenting with different routing protocols to understand each one's characteristics, advantages, and disadvantages, focused on measuring convergence time and behavior under different failure scenarios. A key requirement for experimentation is to have the ability to decode protocol messages, typically analyzing control-plane traffic captures. While this is straight forward for established protocols such as BGP and IS-IS, it is challenging for newer, under development ones, such as RIFT (Routing in Fat Trees). In this work, we present an implementation of a RIFT packet dissector for Wireshark, which permits to analyze control-plane traffic under different scenarios. We tested the dissector with two different RIFT implementations, and it successfully dissected them both. Moreover, our analyzer can be easily extended to parse any RIFT generated Thrift code.