  With the increasing demand for communication between blockchains, improving
the performance of cross-chain communication protocols becomes an emerging
challenge. We take a first step towards analyzing the limitations of
cross-chain communication protocols by comprehensively evaluating Cosmos
Network's Inter-Blockchain Communication Protocol. To achieve our goal we
introduce a novel framework to guide empirical evaluations of cross-chain
communication protocols. We implement an instance of our framework as a tool to
evaluate the IBC protocol. Our findings highlight several challenges, such as
high transaction confirmation latency, bottlenecks in the blockchain's RPC
implementation and concurrency issues that hinder the scalability of the
cross-chain message relayer. We also demonstrate how to reduce the time
required to complete cross-chain transfers by up to 70% when submitting large
amounts of transfers. Finally, we discuss challenges faced during deployment
with the objective of contributing to the development and advancement of
cross-chain communication.
