Controlling services in a circuit-switched network from a packet network

A method of operating a subscriber emulation system comprising:

• detecting that a call either originates from or is intended for a subscriber being served by a telephony switch residing in a circuit-switched network, wherein the telephony switch includes an end office (EO) or a mobile switching center (MSC), and wherein detecting that the call originates from or is intended for a subscriber being served by the telephony switch includes receiving an Intelligent Network trigger that indicates one of a group consisting of:
• an incoming call intended for the subscriber was received by the telephony switch;
• and
• an outgoing call originated from the subscriber was detected by the telephony switch;
• instructing the telephony switch residing in the circuit-switched network to intercept and reroute the call signaling and bearer paths toward the subscriber emulation system, wherein the subscriber emulation system includes a packet-switched interface and a circuit-switched interface, wherein instructing the telephony switch to reroute the call comprises instructing the telephony switch to route the call through the circuit-switched network to a gateway that routes the call to at least one of a trunk agent or a line agent, which is configured to act on behalf of an entity that initiated the call, wherein the gateway, the trunk agent, and the line agent are associated with the subscriber emulation system;
• receiving the call from the telephony switch via the circuit-switched interface of the subscriber emulation system;
• and
• routing the call to a service node in an Internet Protocol-based packet network via the packet network, wherein the subscriber emulation system is presented as a user agent that registers the subscriber into the packet network and acts on behalf of the subscriber to the service node and the service node processes the call to provide services for the call.