string RegistrationInfo(DN dn)
 {
     if (dn == null)
     {
         return("<NULL>");
     }
     return($"{DNListener.DNInfo(dn)}=Registrar\n[\n{string.Join("\n    ", dn.GetRegistrarContactsEx().Select(x => $"ID/Hash={x.ID} - {x.Contact}"))}\n]");
 }
 string VoiceMailInfo(DN dn)
 {
     return($"{DNListener.DNInfo(dn)}=VMBOX({dn?.VoiceMailBox.New}/{dn?.VoiceMailBox.Total})");
 }