Multimedia conference system and method which enables communication between private network and Internet

• US 20060203749A1
• Filed: 07/27/2005
• Published: 09/14/2006
• Est. Priority Date: 03/09/2005
• Status: Active Grant

• Current Assignee: Plustek Incorporated
• Original Assignee: Plustek Incorporated
• Inventors: Tseng, Mu-Chun
• Granted Patent: US 8,767,590 B2
• Time in Patent Office: Days
• US Class Current: 370/260
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/4038 with floor control

Abstract

The present invention discloses a multimedia conference system and method that enables peer-to-peer communication between private network and the Internet. The multimedia conference system and method that enables direct peer-to-peer communication between private network and the Internet includes: a plurality of user agents (to receive call requests) constituting a local network; a calling terminal positioned outside the local network and connected to the local network via Internet; a network address translation (NAT) positioned on the gate of the local network as barrier between the calling terminal and the user agent, and a SIP Proxy Server positioned between the calling terminal and private network and logically installed in parallel with said NAT to receive session initiation protocol messages transmitted from the calling terminal, connect, and transmit IP addresses, so as to send the message to specific User Agent(s).

Claims

1. A multimedia conference system that enables communication between private network and the Internet, including:

a plurality of user agents (to receive call requests) constituting a local network;

a calling SIP terminal positioned outside the local network and able to connect with the private network via Internet;

a network address translation (NAT) positioned on the gate of the local network as barrier between the calling terminal and the user agent;

a SIP Proxy Server positioned between the calling terminal and private network and logically installed in parallel with said NAT to receive session initiation protocol messages transmitted from the calling terminal, connect, and transmit IP addresses, so as to send the message to specific User Agent(s)

2. The multimedia conference system according to claim 1, wherein said SIP Proxy Server selects specific User Agent in response to the call (INVITE) from the calling terminal, performing as the interface to connect both sides of the conference communication.

3. The multimedia conference system according to claim 1, wherein said Proxy Server implements calls and connection for the conference communication in accordance with SIP protocol.

4. The multimedia conference system according to claim 1, wherein said Proxy Server has more than two Network Interfaces, among which, at least one is connected to the public network and at least one is connected to the private network.

5. The multimedia conference system according to claim 4, wherein said Network Interface connected to the public network is configured with independent Public IP, and said Network Interface connected to the private network is configured with the IP address defined by private network.

6. The multimedia conference system according to claim 5, wherein said Proxy Server transfers calls from the calling SIP terminal to individual User Agents.

7. The multimedia conference system according to claim 6, wherein said Proxy Server logically includes a Registration Server so that said a plurality of User Agents can register URI (Uniform Resource Identifier) to the Registration Server.

8. The multimedia conference system according to claim 7, wherein said Proxy Server can obtain the Contact List of User Agents with registered URI from the Registration Server, and transmit calls from the calling SIP terminal to individual User Agents by means of URI locating.

9. The multimedia conference system according to claim 8, wherein said Proxy Server applies the approach of “

Backend to Backend User Agent (B2BUA)”

to perform as the call mediation between the calling SIP terminal and User Agents.

10. The multimedia conference system according to claim 9, wherein the Backend to Backend User Agent of said Proxy Server ties two call legs of “

calling terminal to User Agents” and

“

User Agents to calling SIP terminal”

.

11. The multimedia conference system according to claim 10, wherein the Backend to Backend User Agent of said Proxy Server also establishes a RTP RELAY mechanism between the “

calling SIP terminal” and

“

User Agents”

.

12. The multimedia conference system according to claim 10, wherein said Proxy Server processes real-time multimedia conference communication an approach that complies with RTP (Real Time Transport Protocol).

13. A multimedia conference system that enables direct communication between private network and Internet, including:

a plurality of user agents to constitute a local network;

a proxy server connected to the user agents via the local network, performing as the interface to public network to receive session initiation protocol messages transmitted from the user agents, connect, and transmit IP addresses;

a network address translation (NAT) positioned between the called terminal and the local network and logically deployed in parallel with the proxy server;

14. The multimedia conference system according to claim 13, wherein the Proxy Server executes the DNS lookup on the call (INVITE) transmitted from the User Agent to connect the called SIP terminal as the interface between both sides of the conference communication.

15. The multimedia conference system according to claim 13, wherein the Proxy Server implements calls and connection for the conference communication in accordance with SIP protocol.

16. The multimedia conference system according to claim 13, wherein said Proxy Server has more than two Network Interfaces, among which, at least one is connected to the public network and at least one is connected to the private network

17. The multimedia conference system according to claim 16, wherein said Network Interface connected to the public network is configured with independent Public IP, and said Network Interface connected to the private network is configured with the IP address defined by private network.

18. The multimedia conference system according to claim 17, wherein said Proxy Server transfers calls from the User Agent to the called SIP terminal.

19. The multimedia conference system according to claim 18, wherein said Proxy Server logically includes a Registration Server so that said a plurality of User Agents can register URI (Uniform Resource Identifier) to the Registration Server.

20. The multimedia conference system according to claim 20, wherein said Proxy Server applies the approach of “

Backend to Backend User Agent (B2BUA)”

to perform as the call mediation between the User Agent and the called terminal.

21. The multimedia conference system according to claim 21, wherein said Backend to Backend User Agent of the Proxy Server ties two call legs of “

User Agent to the called SIP terminal” and

“

the called SIP terminal to User Agent”

.

22. The multimedia conference system according to claim 22, wherein said Backend to Backend User Agent of the Proxy Server also establishes a RTP RELAY mechanism between the “

User Agent” and

the “

called SIP terminal”

.

23. The multimedia conference system according to claim 22, wherein said Proxy Server processes real-time multimedia conference communication in an approach that complies with RTP (Real Time Transport Protocol).

24. A method for multimedia conference that enables direct communication between private network and public network, including:

(1) A Proxy Server deployed logically in parallel with NAT, to receive incoming call request sending from the calling SIP terminal which connects to the Proxy Server via Internet, validate the request, and record the routing information for the call;

(2) Forwarding the call request to specified User Agent and establishing the call connection;

(3) Conducting multimedia conference communication between the calling SIP terminal and specified User Agent in the private network.

25. The method for multimedia conference according to claim 24, wherein said (step 2) further includes:

(2-1) User Agent in the private network registers its URI (Uniform Resource Identifier) associated with contact information to the Registration Server logically included in the Proxy Server.

26. The method for multimedia conference according to claim 25, wherein said (step 2) further includes:

(2-2) Proxy Server obtains the Contact List of User Agents from said Registration Server and, by means of URI query, and forwards the calls originated from the calling SIP terminal to individual User Agent(s).

27. The method for multimedia conference according to claim 26, wherein said step (3) further includes:

(3-1) “

Backend to Backend User Agent (B2BUA)”

is applied as the call mediation to process multimedia conference communication between the calling SIP terminal in the public network and the assigned User Agents in the private network.

28. The method for multimedia conference according to claim 27, wherein, said Backend to Backend User Agent (B2BUA) in (step 3-1) further sets up the two call legs (one connected to the calling SIP terminal and the other connected to the designated User Agent) as the call proceeds.

29. The method for multimedia conference according to claim 28, wherein, said (step 3-1) further includes:

(3-2) Backend to Backend User Agent (B2BUA) establishes the RTP RELAY mechanism between the User Agents and calling SIP terminal while the call proceeds.

30. The method for multimedia conference according to claim 29, wherein, said (step 3-2) applies an approach that complies with RTP (Real Time Transport Protocol) to achieve real-time multimedia conference communication between each party.

31. A method for multimedia conference that enables direct communication between private network and the public network, including:

(1) A Proxy Server deployed logically in parallel with NAT to receive incoming call request originating from the User Agent located inside private network, validate the request, and record the routing information for the call;

(2) The Proxy Server performs DNS lookup based on the request originating from User Agent and forward the call request to called SIP terminal which is located outside the private network to establish the call connection.

(3) Conducting multimedia conference communication between the calling User Agent and the called SIP terminal.

32. The method for multimedia conference according to claim 31, wherein, said (step 1) further includes:

(1-1) User Agents in the private network register their URI (Uniform Resource Identifier) information associated with contact information to the Registration Server logically included in the Proxy Server.

33. The method for multimedia conference according to claim 32, wherein, said (step 3) further includes:

(3-1) Backend to Backend User Agent (B2BUA) is applied as the call mediation for multimedia conference communication between User Agents in the private network and the called terminal outside the private network.

34. The method for multimedia conference according to claim 33, wherein, said step (3-1) applies Backend to Backend User Agent (B2BUA) to set up the two call legs (one connected to the calling User Agent and the other connected to the called terminal) while the call proceeds.

35. The method for multimedia conference according to claim 34, wherein, said (step 3-1) further includes:

(3-2) Backend to Backend User Agent (B2BUA) establishes RTP RELAY mechanism between “

User Agents” and

“

the called terminal”

while the call proceeds.

36. The method for multimedia conference according to claim 35, wherein, said (step 3-2) applies an approach that complies with RTP(Real Time Transport Protocol) to process real-time multimedia conference communication between each party.

37. A computer-readable medium that enables peer-to-peer communication between private network and public network, including the following computer-executable instructions:

(1) Receive a call request message originating from the calling terminal that locates outside the private network and connects to Proxy server via Internet;

(2) Record the routing information for the call;

(3) Allow User Agent in the private network to register its URI;

(4) Obtain Contact List of User Agents by requesting URI and forward the request to specified User Agent so as to establish intended call connection;

(5) Construct multimedia conference communication between the calling SIP terminal and the called User Agent

38. The computer-readable medium according to claim 37, wherein, said computer-executable instructions apply approaches that comply with SIP to process call signaling and session establishment for the conference communication between the private network and public network.

39. The computer-readable medium according to claim 37, wherein, further includes applying “

Backend to Backend User Agent (B2BUA)”

as the call mediation between calling SIP terminal issuing a call across Internet and the called User Agents in the private network.

40. The computer-readable medium according to claim 39, wherein, said computer-executable instructions applies “

Backend to Backend User Agent”

to set up the two call legs (one connected to the calling User Agent and the other connected to the called terminal) while the call proceeds.

41. The computer-readable medium according to claim 40, wherein, said computer-executable instructions further includes:

applying “

Backend to Backend User Agent, B2BUA”

to establish RTP RELAY mechanism between the calling SIP terminal and User Agents.

42. A computer-readable medium that enables peer-to-peer communication between private network and public network, including the following computer-executable instructions:

(1) Receive a call request message originating from User Agent in the private network;

(2) Record the routing information for the call;

(3) Apply DNS lookup in response to the call request originating from the User Agent and forward the call request to the called SIP terminal located outside the private network to establish call connection;

(4) Construct multimedia conference communication between the calling User Agent and the called SIP terminal.

43. The computer-readable medium according to claim 42, wherein, said computer-executable instructions applies approaches that comply with SIP to process the calling, connection, and session management for conference communication between the private network and the public network.

44. The computer-readable medium according to claim 42, which further includes:

applying “

Backend to Backend User Agent (B2BUA)”

as the call mediation between User Agents in the private network and called SIP terminal outside the private network.

45. The computer-readable medium according to claim 43, wherein said computer-executable instructions applies “

Backend to Backend User Agent (B2BUA)”

to tie the two call legs of “

User Agents to called SIP terminal” and

“

called SIP terminal to User Agents”

to mediate the dialogue between the calling SIP terminal from the public network and User Agents in the private network.

46. The computer-readable medium according to claim 45, wherein, said computer-executable instructions further includes:

applying “

Backend to Backend User Agent, B2BUA”

to establish RTP RELAY mechanism between the calling SIP terminal and User Agents.