This case arose when Sprint asserted various voice-over-IP patents against Cox, and subsequently a district court granted partial summary judgment to Cox on the basis that the "processing system" recited in the claims was an indefinite limitation. On appeal, the Federal Circuit held that the "processing system" played no role in defining the function or process of the method claims, and as the asserted claims were method claims, patentability and novelty resides in the performancing of those steps itself. In supporting this argument, the court redacted all mentions of "processing system" from the claims, and the resulting method claims did not change in scope. As such, the court ruled that there was no indefiniteness issue.
For practitioners, this reaffirms the understanding that a general purpose computer, such as a "processing system", need not necessarily be fleshed out in complete detail, wherein the novelty of an invention lies completely with the software process itself, i.e. a set of outputs based on the combination of a rules set applied to various inputs.
For the full opinion -- http://www.cafc.uscourts.gov/sites/default/files/opinions-orders/16-1013.Opinion.9-21-2016.1.PDF