Causal consistency is the strongest consistency model under which low-latency and high-availability can be achieved. In the past few years, many causally consistent storage systems have been developed. The long-term goal of this initial work is to perform a deep study and comparison of the different implementations of causal consistency. We identify that protocols that provide causal consistency share the well-known DUR (deferred update replication) algorithmic structure and observe that existing implementations of causal consistency fall into a sub-category of DUR that we name A-DUR (Asynchronous-DUR). In this work, we present the A-DUR algorithmic structure, the pseudocode for the instanti-ation of two causally consistent protocols under the G-DUR framework, and describe the empirical study we intend to perform on causal consistency.