To access the public network from an extension in your internal system, a FAC for ARS must be set up on your system. In the US, the number 9 is usually the ARS FAC to use to make an outgoing call.
Procedure
Enter change dialplan analysis.
In an empty row, type the number in the Dialed String column that you want to use as the FAC for ARS.
In the Total Length column, type the total number of digits for the FAC for ARS.
In the Call Type column, type fac.
Select Enter to save your changes.
Enter change features-access-codes.
In the Auto Route Selection (ARS) Access Code 1 field, type the number that you set up in Step 2.
