VoIP multiline failover

1. A communications method, comprising:

receiving a user request to initiate a telephonic connection from a local site, using a VoIP telecommunication device which has by itself no functionality to failover to transfer traffic onto at least one backup tunnel in the event of a link failure;

establishing over wide area network links at least two VPN tunnels between a controller at the local site and another controller; and

transmitting VoIP traffic over at least one of the VPN tunnels from the controller at the local site to the other controller;

wherein the establishing step includes an inviting location initiating an SIP/SDP INVITE at least in part by sending to an invited location an SIP/SDP INVITE packet and includes sending to the invited location a primary IP address of the inviting location and a backup IP address of the inviting location in a request packet, and includes the inviting location receiving from the invited location in a response packet a primary IP address of the invited location and a backup IP address of the invited location.

2. The method of claim 1 , wherein the method dynamically establishes at least one of the VPN tunnels in response to receiving the user request.

3. The method of claim 2 , wherein the step of dynamically establishing a VPN tunnel comprises the controller at the local site sending, transparently to the user, at least the following to the other controller: a VoIP call initiation message, a primary channel IP address, at least one backup channel IP address.

4. The method of claim 2 , further comprising the controller at the local site sending the other controller a VoIP call termination message, and then tearing down the dynamically established VPN tunnel.

5. The method of claim 1 , wherein the method establishes at least one of the VPN tunnels as a static tunnel before receiving the user request.

6. The method of claim 1 , wherein the method establishes at least one of the VPN tunnels as a call-specific tunnel, namely, a tunnel that is dedicated to VoIP traffic.

7. The method of claim 1 , wherein the method establishes at least two physically separate VPN tunnels of the same type (static versus dynamic).

8. The method of claim 1 , further comprising detecting failure of the VPN tunnel during a call and changing a data path during the call to transmit packets over at least one non-failed tunnel.

9. The method of claim 8 , wherein detecting failure of the VPN tunnel during a call occurs within a previously defined time period of the physical failure of the VPN tunnel.

10. The method of claim 1 , wherein transmitting packets comprises identifying VoIP connection control packets and sending them into the VPN tunnel.

11. The method of claim 1 , wherein transmitting packets comprises identifying VoIP packets and sending them into a dynamically established call-specific VPN tunnel while excluding non-VoIP packets from the VPN tunnel.

12. The method of claim 1 , wherein transmitting packets comprises identifying VoIP packets and sending them into a dynamically established VPN tunnel while committing minimum latency, jitter and packet loss as previously specified for improved quality of call.

13. The method of claim 1 , wherein transmitting packets comprises identifying VoIP packets and sending them into a call-specific VPN tunnel while committing minimum latency, jitter and packet loss as previously specified for improved quality of call.

14. The method of claim 1 , wherein transmitting packets comprises performing network address translation (NAT) on packets before the controller at the local site sends them over the VPN tunnel, such that the intermediate site sees a public IP address for the local site in the packets instead of seeing a private IP address of the local site.

15. The method of claim 1 , further comprising a PBX/soft-switch at an intermediate site terminating the call on a VoIP device.

16. The method of claim 1 , further comprising a PBX/soft-switch at an intermediate site terminating the call on a PSTN device.

17. A communications method, comprising:

receiving a user request to initiate a telephonic connection from a local site, using a VoIP telecommunication device which has by itself no functionality to failover to transfer traffic onto at least one backup tunnel in the event of a link failure;

dynamically establishing at least two tunnels over wide area network links between a controller at the local site and another controller, in response to receiving the user request; and

transmitting VoIP traffic over at least one of the tunnels from the controller at the local site to the other controller;

wherein the establishing step includes an inviting location initiating an SIP/SDP INVITE at least in part by sending to an invited location an SIP/SDP INVITE packet and includes sending to the invited location a primary IP address of the inviting location and a backup IP address of the inviting location in a request packet, and includes the inviting location receiving from the invited location in a response packet a primary IP address of the invited location and a backup IP address of the invited location.

18. The method of claim 17 , wherein the method also encrypts and/or compresses VoIP traffic.

19. A communications method, comprising:

receiving a user request to initiate a telephonic connection from a local site, using a VoIP telecommunication device which has by itself no functionality to failover to transfer traffic onto at least one backup tunnel in the event of a link failure;

establishing at least two call-specific tunnels over wide area network links between a controller at the local site and another controller, in response to receiving the user request; and

transmitting VoIP traffic over at least one of the tunnels from the controller at the local site to the other controller;

wherein the establishing step includes an inviting location initiating an SIP/SDP INVITE at least in part by sending to an invited location an SIP/SDP INVITE packet and includes sending to the invited location a primary IP address of the inviting location and a backup IP address of the inviting location in a request packet, and includes the inviting location receiving from the invited location in a response packet a primary IP address of the invited location and a backup IP address of the invited location.

20. The method of claim 19 , wherein the method dynamically establishes the tunnels in response to receiving the user request.