For each SIP provider, one can setup the area code/country code preferences in the Fritz!box. What exactly is the point of this? 1. to make national calls without entering the full 00496107......... number (so we can just dial 06107.... and the Fritz!box will dial 00496107.....) 2. to make local calls without entering the area code 3. to change the appearance of incoming call numbers (so the caller-ID would show 06107....... instead of 00496107.......) And how exactly should they be used? I know it depends on the used SIP provider of course, but the explanation is not really clear to me... I entered my area code and my country code, but what is the difference between "user area code" ("Ortskennzahl verwenden") and "Keep National Direct Dialing (NDD) prefix" ("Ortskennzahl-Prefix beibehalten") ? Who can explain the purpose of the four checkmarks clearly to me? Also, I noticed that the German version has the option "Suffix für Internetrufnummern". This is not available in the English version. What is the purpose of this? Thanks!