CG-IEIK-001 Issue 4-August 1, 2005

Foreign Exchange (FX) service allows a subscriber to obtain dial tone from a central office that is "foreign" to the physical location of the subscriber. For example, a New Orleans subscriber may opt for FX service that provides dial tone from Shreveport. This makes calls to Shreveport local instead of long distance. Additionally, FX service can be applicable to two exchanges within the same City / County / Parish (a definition of FX service is that it must be different exchanges).

When the telephone numbers for an NXX are loaded, that load will also include all FX lines.

For those FX numbers with an address of a physical location within the tandem that serves the address, the address will validate to the MSAG and route to the PSAP serving that ESN.

For those FX numbers with an address of a physical location outside the tandem that serves the City / County / Parish, the address in the E911 database should be changed by the ICO to add information explaining that this is a FX line. The call will route accordingly based on ESN assignment.