Abstract: An approach provides interdomain traversal to support packetized voice transmissions. A centralized data store, maintained by a service provider, stores one or more user identifiers and an associated directory number. The centralized data store also stores routing information including one or more communication paths corresponding to the user identifier, wherein the routing information includes a data path or a circuit-switched path for establishing a call to the user. In response to a request for establishing the call to the directory number, the data store retrieves the routing information for use to establish the call.

Abstract: An approach provides interdomain traversal to support packetized voice transmissions. A signaling message is received for establishing a voice call from a first endpoint associated with a first domain to a second endpoint associated with a second domain. The first endpoint queries a STUN (Simple Traversal of UDP (User Datagram Protocol)) server to determine information relating to a firewall and network address translator that the first endpoint is behind, and to log into a TURN (Traversal Using Relay NAT (Network Address Translation)) server configured to establish a media path between the first endpoint and the second endpoint. A first proxy server serving the first endpoint communicates with an ENUM (Electronic Number) server to convert a directory number corresponding to the second endpoint to a network address. The first proxy server communicates with a second proxy server serving the second endpoint to establish the voice call.

Abstract: An approach provides interdomain traversal to support packetized voice transmissions. A request is received and specifies a directory number for establishing a communication session from a first endpoint to a second endpoint. The first endpoint is behind a first network address translator of a first domain, and the second endpoint is within a second domain. A service provider network is accessed to determine a network address for communicating with the second endpoint based on the directory number, to determine existence of a second network address translator within the second domain, and to establish, if the network address can be determined, a media path between the first endpoint and the second endpoint based on the network address to support the communication session. An encrypted session is established with a proxy server according to a cryptographic protocol to support the media path. The proxy server resides within the second domain.

Abstract: An approach provides interdomain traversal packetized voice transmissions. A request is received from a first endpoint of a first domain for establishing a communication session with a second endpoint of a second domain. A tunnel is established by a TURN (Traversal Using Relay NAT (Network Address Translation)) server to support the communication session. The TURN server is controlled by a service provider as part of a managed communication service. The tunnel traverses a first firewall and a first network address translator of the first domain and a second firewall and a second network address translator of the second domain to reach the second endpoint, wherein the communication session is encrypted and transported via the tunnel.

Abstract: An approach provides interdomain traversal to support packetized voice transmissions. A request is received from a first endpoint of a first domain for establishing a communication session with a second endpoint of a second domain. Encrypted user credential information is retrieved from a credentials database resident within the first domain, wherein the encrypted user credential includes a password associated with a user associated with the first endpoint. Further, the encrypted user credential information is transmitted to a tunneling server in response to the request, wherein the tunneling server is configured to selectively setup a tunnel to support the communication session based on the encrypted user credential information. The tunnel traverses a first firewall and a first network address translator of the first domain and a second firewall and a second network address translator of the second domain to reach the second endpoint.

Abstract: An approach provides interdomain traversal to support packetized voice transmissions. A request for establishing a voice call is received from a source endpoint behind a first network address translator of a first domain, wherein the request specifies a directory number of a destination endpoint within a second domain. A network address is determined for communicating with the destination endpoint based on the directory number. Additionally, existence of a second network address translator within the second domain is determined. If the network address can be determined, a media path is established between the source endpoint and the destination endpoint based on the network address to support the voice call.