Providing telephony services to terminals behind a firewall and/or a network address translator

• US 8,484,359 B2
• Filed: 08/13/2012
• Issued: 07/09/2013
• Est. Priority Date: 06/14/2001
• Status: Expired due to Fees

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Rockstar Consortium US LP (Rockstar Consortium Inc.)
• Inventors: Sollee, Patrick N.
• Primary Examiner(s): Dalencourt, Yves
• Application Number:
  US13/584,105
• Publication Number:
  US 20120311163A1
• Time in Patent Office: 330 Days
• Field of Search: 709/206, 709/224, 709/227, 709/230
• US Class Current: 709/227
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2517 using port numbers
• CPC Class Codes: H04L 61/2539 Hiding addresses; Keeping addresses anonymous
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 61/2553 Binding renewal aspects, e.g. using keep-alive messages
• CPC Class Codes: H04L 61/2564 for a higher-layer protocol, e.g. for session initiation protocol [SIP]
• CPC Class Codes: H04L 61/2578 without involvement of the NAT server
• CPC Class Codes: H04L 63/0227 Filtering policies mail message filtering H04L51/212
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 63/0254 Stateful filtering
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes
• CPC Class Codes: H04L 63/1458 Denial of Service
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/0078 Security; Fraud detection; Fraud prevention

Abstract

A method and apparatus for allowing telephony or other types of media communications and services to be provided for a device (24) having a private network address that resides behind a firewall and network address and port translation (NAPT) module (which is unaware of the underlying protocol for the communications and services). Examples of the underlying protocol includes the Session Initiation Protocol (SIP) and Real-Time Protocol (RTP). A path through the firewall and NAPT module is defined by use of keep-alive messages communicated through the firewall and NAPT module. Addresses that are allocated by the firewall and NAPT module are associated with the device (24) for both signaling and media communications. A feature of the firewall that enables the provision of telephony and media communications through the firewall that is protocol-unaware is that the firewall allows responses to messages initiated by the device back through the firewall.

Claims

1. A method for communications involving a first terminal coupled to a first side of a firewall and network address translator, the method comprising:

sending, by the first terminal, a first message identifying the first terminal to a node on a second side of the firewall and network address translator, the first message identifying the first terminal as available for a call session;

receiving, by the first terminal, a second message from the node, wherein the first message and the second message cause creation of a signalling connection through the firewall and network address translator and creation of a mapping between a first address of the first terminal and a second address of the first terminal, where the first address is an address assigned to the first terminal on the first side of the firewall and network address translator, and where the second address is an address assigned to the first terminal on the second side of the firewall and network address translator;

repeatedly sending keep-alive messages to maintain the mapping at the firewall and network address translator;

communicating messages, by the first terminal through the firewall and network address translator using the mapping maintained at the firewall and network address translator, to establish a first call communication session with a second terminal using a first call communication session connection; and

exchanging media packets with the second terminal via the first call communication session connection.

2. The method of claim 1, wherein the keep-alive messages maintain the existing signalling connection through the firewall and network address translator to thereby maintain the mapping at the firewall and network address translator.

3. The method of claim 2, wherein communicating the messages, by the first terminal through the firewall and network address translator using the mapping maintained at the firewall and network address translator, to establish the first communication session with the second terminal using the first call communication session connection comprises communicating the messages with the node over the existing signalling connection maintained through the firewall and network address translator.

4. The method of claim 1, wherein the first call communication session connection is different from the existing signalling connection.

5. The method of claim 1, wherein the first call communication session is established under control of the node.

6. The method of claim 1, further comprising receiving a communication session request, by the first terminal, using the mapping maintained at the firewall and network address translator.

7. The method of claim 6, wherein the communication session request is received by the first terminal over the existing signalling connection.

8. The method of claim 1, wherein repeatedly sending the keep-alive messages to maintain the mapping at the firewall and network address translator comprises maintaining a timer and sending the keep-alive messages responsive to the timer.

9. The method of claim 8, wherein the timer is maintained at the first terminal and the keep-alive messages are sent from the first terminal.

10. The method of claim 8, wherein the keep-alive messages are sent to the node over the signalling connection.

11. The method of claim 1, wherein repeatedly sending the keep-alive messages comprises sending the keep-alive messages at regular periodic time intervals.

12. The method of claim 1, wherein the signalling connection comprises a Session Initiation Protocol (SIP) signalling connection between the first terminal and the node.

13. The method of claim 1, wherein sending the first message comprises sending a registration message to register the first terminal with the node.

14. The method of claim 13, wherein:

sending the registration message comprises sending a Session Initiation Protocol (SIP) REGISTER message; and

communicating the messages to establish the first call communication session comprises communicating a SIP INVITE message.

15. The method of claim 14, wherein sending the registration message comprises sending the registration message to a SIP proxy.

16. The method of claim 15, wherein the node comprises the SIP proxy.

17. The method of claim 1, wherein:

sending the first message and receiving the second message cause registration of the first terminal; and

repeatedly sending the keep-alive messages to maintain the mapping at the firewall and network address translator is performed for a duration of the registration of the first terminal.

18. The method of claim 1, wherein the mapping comprises a mapping between an internal address of the first terminal and an external address of the first terminal.

19. A method for communications involving a first terminal coupled to a first side of a firewall and network address translator, the method comprising:

sending, by the first terminal, a first message identifying the first terminal to a node on a second side of the firewall and network address translator, the first message identifying the first terminal as available for a call session;

receiving, by the first terminal, a second message from the node, wherein the first message and the second message cause creation of a signalling connection through the firewall and network address translator and creation of a mapping between a first address of the first terminal and a second address of the first terminal, where the first address is an address assigned to the first terminal on the first side of the firewall and network address translator, and where the second address is an address assigned to the first terminal on the second side of the firewall and network address translator;

communicating messages, by the first terminal through the firewall and network address translator using the mapping between the first address and the second address, to establish a first call communication session with a second terminal using a first call communication session connection; and

exchanging media packets with the second terminal via the first call communication session connection.

20. The method of claim 19, further comprising repeatedly sending keep-alive messages to maintain the mapping at the firewall and network address translator.