Firewall interface configuration to enable bi-directional VoIP traversal communications

• US 8,434,143 B2
• Filed: 06/07/2012
• Issued: 04/30/2013
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Fortinet Inc.
• Original Assignee: Fortinet Inc.
• Inventors: Xie, Michael
• Primary Examiner(s): Gergiso, Techane
• Application Number:
  US13/491,346
• Publication Number:
  US 20120246712A1
• Time in Patent Office: 327 Days
• Field of Search: 726/14, 726/11, 713/151, 713/153
• US Class Current: 726/14
• CPC Class Codes: H04L 61/2521 Translation architectures other than single NAT servers
• CPC Class Codes: H04L 61/4535 using an address exchange platform which sets up a session between two nodes, e.g. rendezvous servers, session initiation protocols [SIP] registrars or H.323 gatekeepers
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 63/0245 Filtering by information in the payload
• CPC Class Codes: H04L 63/0281 Proxies
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1066 Session management
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

Methods and systems for an intelligent network protection gateway (NPG) and network architecture are provided. According to one embodiment, a firewall provides network-layer protection to internal hosts against unauthorized access by hosts of an external network by performing network address translation (NAT) processing of Internet Protocol (IP) addresses. The firewall changes data in headers of VoIP packets and corresponding data contents of the VoIP packets, to enable bi-directional VoIP communications. An external VoIP interface of the firewall receives incoming VoIP packets having a user alias (e.g., an email address) and an indication regarding a VoIP port of external interface. The packets are directed to an appropriate internal host by the firewall performing port address forwarding based on the port indication to a Media Gateway Control Protocol (MGCP) media gateway within the internal network that maintains a mapping of user aliases to private addresses of the internal hosts.

Claims

1. A method comprising:

a firewall, interposed between an internal network and an external network, providing network-layer protection against unauthorized access by hosts associated with the external network to a plurality of internal hosts associated with the internal network by performing network address translation (NAT) processing of Internet Protocol (IP) addresses associated with the plurality of internal hosts;

the firewall providing application-layer protection from the external network on behalf of the plurality of internal hosts and supporting VoIP services without compromising internal network security by actively processing signaling protocols associated with Voice over IP (VoIP) sessions, including

distinguishing among VoIP packets and non-VoIP packets,

understanding and parsing the VoIP packets at the application layer, and

performing content-aware NAT by changing data in headers of the VoIP packets and also changing data contents in the VoIP packets corresponding to data changed in the headers to enable bi-directional VoIP communications among one or more of the plurality of internal hosts and one or more of the hosts associated with the external network;

providing a plurality of VoIP ports to an external VoIP interface of the firewall;

receiving by the external VoIP interface incoming VoIP packets each having associated therewith a user alias and an indication regarding one of the plurality of VoIP ports;

causing each of said received multiple incoming VoIP packets to be directed to an appropriate internal host of the plurality of internal hosts by performing by the firewall port address forwarding based on the port indication to a Media Gateway Control Protocol (MGCP) media gateway within the internal network that maintains a mapping of user aliases to private addresses of the plurality of internal hosts;

wherein the user alias comprises an email address of a user associated with one of the plurality of internal hosts; and

wherein the firewall comprises an intelligent network protocol gateway.

2. The method of claim 1, wherein said changing data in headers of the VoIP packets further comprises changing a source IP address and a port number in the headers of the VoIP packets.

3. The method of claim 1, wherein said distinguishing among VoIP packets and non-VoIP packets is based on a standard port address.

4. The method of claim 1, further comprising conducting through the external VoIP interface a network meeting between an external network user and at least two internal network users.

5. The method of claim 1, further comprising conducting through the external VoIP interface a network meeting between an internal network user and at least two external network users.

6. The method of claim 1, further comprising implementing said firewall as an application specific integrated circuit (ASIC).

7. An intelligent network protection gateway device comprising:

a network address translation (NAT) processing means, configured to be interposed between an internal network and an external network, for providing network-layer protection against unauthorized access by hosts associated with the external network to a plurality of internal hosts associated with the internal network by performing translation of Internet Protocol (IP) addresses associated with the plurality of internal hosts;

an application-layer protection means, for protecting the plurality of internal host from the external network and for supporting VoIP services without compromising internal network security by actively processing signaling protocols associated with Voice over IP (VoIP) sessions, including

distinguishing among VoIP packets and non-VoIP packets,

understanding and parsing the VoIP packets at the application layer, and

changing data in headers of the VoIP packets and also changing data contents in the VoIP packets corresponding to data changed in the headers to enable bi-directional VoIP communications among one or more of the plurality of internal hosts and one or more of the hosts associated with the external network;

an external VoIP interface including a plurality of VoIP ports configured to receive incoming VoIP packets each having contained therein an a user alias and an indication regarding one of the plurality of VoIP ports;

wherein said external VoIP interface further comprises a means for directing the incoming VoIP packets to an appropriate internal host of the plurality of internal hosts by performing port address forwarding based on the port indication to a Media Gateway Control Protocol (MGCP) media gateway within the internal network that maintains a mapping of user aliases to private addresses of the plurality of internal hosts;

wherein one or more of said NAT processing means and said application-layer protection means includes (i) logic implemented within an application specific integrated circuit (ASIC) of the intelligent network protection gateway device or (ii) a program storage device readable by one or more processors of the intelligent network protection gateway device, tangibly embodying a program of instructions executable by the one or more processors;

wherein the user alias comprises an email address of a user associated with one of the plurality of internal hosts; and

wherein the mapping maps an e-mail address included in an incoming VoIP message to an internal port number in said internal network.

8. The network protection gateway device of claim 7, wherein said distinguishing among VoIP packets and non-VoIP packets is based on a standard port address.

9. The network protection gateway device of claim 7, wherein the external VoIP interface facilitates network meetings among an external network user and at least two internal network users.

10. The network protection gateway device of claim 7, wherein the external VoIP interface facilitates network meetings among an internal network user and at least two external network users.