Inter working system

• US 8,140,707 B2
• Filed: 04/24/2007
• Issued: 03/20/2012
• Est. Priority Date: 04/24/2006
• Status: Active Grant

• Current Assignee: KT Corporation
• Original Assignee: KT Corporation
• Inventors: Lee, Jang-won, Lee, Ho-Jin, Bak, Sang-Man
• Primary Examiner(s): Eng, David
• Application Number:
  US12/298,426
• Publication Number:
  US 20090180476A1
• Time in Patent Office: 1,792 Days
• Field of Search: 709/245, 370/401, 370/466, 370/351
• US Class Current: 709/245
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2575 using address mapping retrieval, e.g. simple traversal of user datagram protocol through session traversal utilities for NAT [STUN]
• CPC Class Codes: H04L 61/2585 through application level gateway [ALG]
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1043 Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]

Abstract

Disclosed are examples of an interworking system. In some embodiments, the interworking system includes a STUN server and an application layer gateway (ALG) server. The STUN server can be configured to provide binding information. The application layer gateway (ALG) server can include an IP masquerading performer, a STUN client performer, an address translator and a determiner.

Claims

1. An interworking system, comprising:

a simple traversal under user datagram protocol through network address translator (STUN) server configured to provide public IP binding information based on a private IP address; and

an application layer gateway (ALG) server including;

an IP masquerading performer configured to change header information of a public IP binding request into private media receiving address information extracted from a payload of a packet received from a call transmitting terminal;

a STUN client performer configured to;

transmit the public IP binding request with the header information, as changed by the IP masquerading performer, to the STUN server, and

receive a binding request response included in the header information, as changed from the STUN server, wherein the header information includes global media receiving address information;

an address translator configured to change the private media receiving address information of the packet received from the from the call transmitting terminal into global media receiving address information extracted from the binding request response; and

a determiner configured to determine whether to drive the IP masquerading performer depending on whether a network of the destination specified in the header of a call connection request packet corresponds to a source network.

2. The interworking system of claim 1, wherein the IP masquerading performer comprises:

a header information setting module configured to change a source IP address and a source port of the header information of the public IP binding request into an IP address and a port of the private media receiving address information in the private IP format; and

a header checksum calculation module configured to calculate a checksum of the header information by applying the source IP address and the source port as changed.

3. The interworking system of claim 1, wherein the STUN server comprises:

a storage unit configured to store setting information related to processing a public IP binding request and a public IP binding response; and

a STUN performer configured to;

load header information of a public IP binding request that has passed through a network address translator (NAT) in the public IP binding response by using the setting information of the storage unit, and

transmit the public IP binding response to the ALG server.

4. An interworking system, comprising:

a STUN server configured to provide public IP binding information of a private IP address; and

an application layer gateway (ALG) server including;

a determiner configured to;

check a transmitting subject identifier and a transmitting method identifier of a session initiation protocol (SIP) message received from a call transmitting terminal,

determine whether an originating network of the call transmitting terminal corresponds to a destination network of a call receiving terminal, and

determine whether the SIP message is a request message or a response message;

an IP masquerading performer configured to insert attribute values extracted from a session description protocol (SDP) field of the SIP message, the attribute values inserted in header information of a public IP binding request according to a determination by the determiner;

a STUN client performer configured to;

transmit the public IP binding request with the header information, as changed by the IP masquerading performer, to the STUN server, and

receive a public IP binding response with the header information as changed with the attribute values; and

a message translator configured to apply the attribute values processed into a public IP format of the SIP message.

5. The interworking system of claim 4, wherein the message translator specifies the public address information or the private IP address of the ALG selected based on the transmitting subject in routing path information of the SIP message.