Routing outbound toll-free calls through a VoIP network

1. A method for routing a toll-free call through a geographically distributed network configured to route calls from call origination endpoints, whereby a call originating from a call origination endpoint may enter the geographically distributed network at any one of a plurality of geographic regions, the method comprising:

receiving a toll-free call from a call origination endpoint;

determining an identifier associated with the call origination endpoint, wherein the identifier is statically associated with a specified geographic region;

if a direct access line (DAL) is not available for providing access to an interexchange carrier (IXC) configured to terminate the toll-free call in the specified geographic region, determining a meet point trunk based on at least a portion of the identifier; and

routing the toll-free call to a local exchange carrier (LEC) via the determined meet point trunk.

2. The method as recited in claim 1 , further comprising determining whether a DAL is available, wherein determining whether a DAL is available comprises:

querying an SMS/800 database; receiving a carrier identification code (CIC) from the SMS/800 database in response to the querying operation; and

searching for an available direct access line (DAL) based on the received CIC.

3. The method as recited in claim 1 , wherein the geographically distributed network comprises a managed backbone Voice over Internet Protocol (VoIP) network.

4. The method as recited in claim 1 , wherein the identifier comprises a telephone number in the form NPA-NXX-YYYY.

5. The method as recited in claim 4 , wherein determining a meet point trunk comprises looking up a route plan mapped to a range of NPA/NXX numbers in a route plan database.

6. The method as recited in claim 5 , further comprising provisioning a plurality of CIC-based route plans and a plurality of originating endpoint number (OEN)-based route plans.

7. The method as recited in claim 6 , further comprising mapping each of a plurality of meet point trunks to the range of NPA/NXX numbers.

8. The method as recited in claim 6 , further comprising mapping each of a plurality of DALs to an associated CIC.

9. A non-transitory computer-readable medium having computer-executable instructions causing a computer to perform a process of routing toll-free calls through a geographically distributed network spanning a plurality of regions, and configured to handle toll-free calls from call origination endpoints, wherein the process comprises:

in the geographically distributed network, receiving a toll-free call from a call origination endpoint;

determining one or more interconnection access lines providing access to a regional access carrier, wherein the interconnection access lines are associated with the call origination endpoint's assigned number;

selecting a first one of the plurality of interconnection access lines for routing the toll-free call to the regional access carrier; and

routing the toll-free call to the regional access carrier via the first selected interconnection access line.

10. The computer-readable medium as recited in claim 9 , wherein the process further comprises determining whether a direct access line exists that provides access from the geographically distributed network to an interexchange carrier configured to handle the toll-free call.

11. The computer-readable medium as recited in claim 10 , wherein determining whether a direct access line exists comprises:

querying a carrier identification code (CIC) database configured to supply a CIC associated with a region associated with the origination endpoint's assigned number;

responsively receiving a CIC from the CIC database; and

searching an access line database for a direct access line associated with the received CIC.

12. The computer-readable medium as recited in claim 9 , wherein the process further comprises mapping a plurality of NPA/NXX numbers to an available interconnection access line.

13. The computer-readable medium as recited in claim 12 , wherein mapping the plurality of NPA/NXX numbers comprises identifying a tandem switch connected to the interconnection access line.

14. The computer-readable medium of claim 11 , wherein the CIC database is at least one of a toll-free call administration database and an ENUM database.

15. A system for routing a toll-free call entering a network to an appropriate carrier, the system comprising:

an inbound gateway device configured to receive a toll-free call from a call origination endpoint having an assigned telephone number and query a core routing engine for a route plan using the assigned telephone number; and

a core routing engine (CRE) configured to select an interconnection access line based on the origination endpoint telephone number, wherein the interconnection access line is connected to a local exchange carrier (LEC) that is operable to route the call to the appropriate carrier.

16. The system as recited in claim 15 , further comprising a provisioning module configured to identify one or more meet point trunks in the network and map a range of NPA/NXX numbers to each of the one or more meet point trunks.

17. The system as recited in claim 15 , wherein the CRE is further configured to look up a Local Access and Transport Area (LATA) associated with the origination endpoint and query a toll-free administration database using the LATA to determine a carrier identification code (CIC) associated with an appropriate interexchange carrier (IXC).

18. The system as recited in claim 15 , further comprising a route plan database having a toll-free route partition, wherein the provisioning module is further configured to store a plurality of route plans associated with toll-free calls.

19. The system as recited in claim 18 , wherein at least one of the plurality of route plans identifies a meet point trunk and an off-network carrier.

20. The system as recited in claim 15 , further comprising an outbound gateway device configured to route the toll-free call via the selected interconnection access line.