E.164 Number
------------

The dial plan is structured such that the calling and called party
numbers for all inbound PSTN calls entering the Unified Communications Manager
are in an E.164 format. The conversion to E.164 takes place at the aggregation
layer or local gateway. Similarly, the calling and called party numbers for all
outbound PSTN calls leaving the Unified Communications Manager are also in an
E.164 format. The conversion to E.164 takes place at the Unified Communications
Manager.

The format of the E.164 number is: +#COUNTRY##NATCODE##FNN#, where:

* '+' is the International Escape Character
* '#COUNTRY#' is the Country Code (1 for United States, 44 for United Kingdom, and so on)


.. note::

   Some countries do not use area codes; for example, Singapore.         
                                                                           
   #NATCODE# - Area Code
   #FNN# - PSTN Subscriber Number