The emphasis on fixed service numbers includes the use of area codes so that the Number Plan is an open plan. Open Number plans are suited to environments where it is important or advantageous to contain the number of digits dialled e.g. as for electro-mechanical switching exchanges or there is a purpose to regional based management of telephony. The Lao PDR open plan using area codes has meant that local calling has required the caller to dial only the local subscriber number. This would have been advantageous in an era when most subscribers used mechanical dial phones (usually rotary dial), and the majority of traffic was local. Modern circumstances and looking forward neither of these preconditions would apply. Users are already dialling full length numbers for calls to mobile and WLL services
Modern and forward looking circumstances need to reflect a much more geographically and demographically mobile population so that distance calling is a larger component of all calling. Additionally the era and use of electro-mechanical switching exchanges and mechanical dial phones is past. Most subscribers today already use electronic telephones in which the telephone numbers that may be called are stored in the telephone memory and dialling consists of selection of the person to be called rather than dial the telephone number (and all its digits) directly. Accordingly Open Plan design is less important and attractive than as was the case in the past.
Additionally a closed number plan:
• immediately expands useable fixed number space by 20%; and
• removes all restrictions on the use of the digits ‘0’ and ‘1 making these rages more useable and flexible; and
• represents modern and best practice in number planning.