Method and system for providing party line emulation in a SIP-based network

1. A method, comprising:

receiving an incoming call from a calling party for a plurality of members of a group at an SIP server;

transmitting, from the SIP server, an invite message to the plurality of members, wherein the invite message comprises one or more addresses that specifies each of the members of the group;

identifying an acceptance of the invite message by at least one accepting member of the plurality of members;

transmitting, from the SIP server, a cancel message to at least one member of the plurality of members, wherein the cancel message is sent after the identified acceptance;

establishing a SIP-based active dialog between the calling party and the at least one member;

recognizing a reverting call;

identifying when a reverting call originator goes on-hook;

alerting one or more members of the group;

identifying when the one or more devices goes off-hook; and

providing a reverting call emulation service when establishing the SIP-based active dialog.

2. The method of claim 1 , wherein the incoming call is received from a packet switched network.

3. The method of claim 1 , wherein the one or more address comprise a member-specific address for each of the members of the group.

4. The method of claim 1 , wherein the invite message comprises a header that specifies an alerting pattern.

5. The method of claim 4 , wherein the alerting pattern comprises selective alerting.

6. The method of claim 5 , wherein selective alerting comprises alerting a device associated with each of the plurality of members individually.

7. The method of claim 4 , wherein the alerting pattern comprises semi-selective alerting.

8. The method of claim 4 , wherein the alerting pattern comprises alerting a device associate with each of the plurality of members simultaneously.

9. The method of claim 4 , wherein the alerting pattern comprises alerting device associate with each of the plurality of members with a different ring pattern.

10. The method of claim 4 , wherein the alerting pattern comprises a distinctive ringing pattern based on at least one of the following: a calling party number, a called party number, a priority of a call, and an origin of a call relative to a specific caller group or local area.

11. The method of claim 1 , wherein establishing the active dialog further comprises determining when a member is off-hook or on-hook.

12. A non-transitory computer readable medium comprising computer executable instructions which when executed causes a computer to perform:

receiving an incoming call from a calling party for a plurality of members of a group at an SIP server;

transmitting, from the SIP server, an invite message to the plurality of members, wherein the invite message comprises one or more addresses that specifies each of the members of the croup;

identifying an acceptance of the invite message by at least one accepting member of the plurality of members;

transmitting, from the SIP server, a cancel message to at least one member of the plurality of members, wherein the cancel message is sent after the identified acceptance;

establishing a SIP-based active dialog between the calling party and the at least one member;

recognizing a reverting call;

identifying when a reverting call originator goes on-hook;

alerting one or more members of the group;

identifying when the one or more devices goes off-hook; and

providing a reverting call emulation service when establishing the SIP-based active dialog.

13. A method, comprising:

identifying, at an SIP device, an incoming call, wherein the incoming call comprises an invite message specifying one or more party addresses;

identifying one or more party addresses from the incoming call;

providing an alerting pattern to a plurality of devices attached to an analog port corresponding to the one or more party addresses;

establishing a SIP-based active call between the caller and a party at the device when at least one of the plurality of devices goes off-hook;

transmitting a cancel message to at least one of the plurality of devices that does not go off-hook;

recognizing a reverting call;

identifying when a reverting call originator goes on-hook; and

providing a reverting call emulation service when one or more devices connected to the analog port goes off-hook.

14. The method of claim 13 , wherein the one or more party addresses are member-specific.

15. The method of claim 13 , wherein the analog port comprises connections to two or more devices.

16. The method of claim 13 , wherein the device is a telephone set.

17. The method of claim 13 , wherein the alerting pattern is based on an alerting voltage applied to the analog port.

18. The method of claim 13 , wherein providing the alerting pattern comprises alerting each of the one or more devices individually.

19. The method of claim 13 , wherein providing the alerting pattern comprises alerting each of the one or more devices simultaneously.

20. The method of claim 13 , wherein providing the alerting pattern comprises alerting each of the one or more devices with a different ring pattern.

21. A non-transitory computer readable medium comprising computer executable instructions which when executed causes a computer to perform:

identifying, at an SIP device, an incoming call, wherein the incoming call comprises an invite message specifying one or more party addresses;

identifying one or more party addresses from the incoming call;

providing an alerting pattern to a plurality of devices attached to an analog port corresponding to the one or more party addresses;

establishing a SIP-based active call between the caller and a party at the device when at least one of the plurality of devices goes off-hook;

transmitting a cancel message to at least one of the plurality of devices that does not go off-hook;

recognizing a reverting call;

identifying when a reverting call originator goes on-hook; and

providing a reverting call emulation service when one or more devices connected to the analog port goes off-hook.