The base condition for a Lync Enterprise Voice deployment to work correctly is to have all telephone numbers formatted in the E.164 standard. The previously mentioned standard requires a plus sign, followed by a maximum of three digits dedicated to Country Code (CC), and the remaining numbers dedicated to national standards, in order to identify subscribers. Depending on the length of the CC, the part that contains the city (area) code, local number, and extensions might vary (the maximum total length, anyway, is 15 digits, excluding extensions). Each country is able to decide how many digits it should use (considering that a 15-digit number allows for 100 trillion different permutations). The ITU E.164 documentation about the number structure for geographic areas (at http://www.itu.int/rec/T-REC-E.164-201011-I/en) divides the number in CC (1-3 digits), National Destination Code (NDC), and Subscriber Number (SN). NDC and SN are collectively called...