RSSAC has begun work to determine a list of parameters that define the desired service trends for the root zone system. These parameters include the measured latency in the distribution of the root zone, the frequency of the updates, and their size. With knowledge of these parameters in hand, RSSAC can then seek to produce estimates of acceptable root zone size dynamics to ensure the overall system works within a set of parameters. The future work to define these parameters will involve RSSAC working closely with the root server operators to gather best practice estimates for the size and update frequency of the root zone. It must be well understood that the measurements described in this document are a response to the current awareness, experience, and understanding of the Root Zone System. As time progresses more, less, or entirely different metrics may be required to investigate new concerns or defined problem statements.