Abstract: The invention relates to a method and an apparatus for controlling seamless handover between heterogeneous networks based on IPv6 over IPv4 tunneling. When IPv6 service is provided using tunneling in an IPv4 based network environment, handover of a mobile terminal between different networks is achieved through switching of an active tunnel and a standby tunnel, and thus handover between different networks is facilitated and data loss is prevented to secure continuity of service provided to the mobile terminal even when the mobile terminal hands over to a heterogeneous network.

Abstract: A method for configuring a closed user network (CUN) using an IP tunneling mechanism and a CUN system are disclosed. In particular, disclosed is a technique of establishing a tunnel between a tunnel end edge device (TEED) and a control server by using an IP tunneling mechanism to allow terminals connected to the TEED to perform communications by using a closed IP, enabling the TEED to provide a network address translation (NAT) function so that the TEED can perform data forwarding like a general NAT, without performing tunneling on a destination IP outside the closed IP section, to perform communication, and allowing a terminal located in an area where the TEED is not provided to directly establish a tunnel with the control server by using a client software to thereby perform communications with a terminal or a server connected to the TEED by using the closed IP.

Abstract: Enclosed is a method of supporting mobility using a security tunnel. For the movement of a terminal in a local network and the movement of a terminal to an external network, an active tunnel and a standby tunnel are set to provide mobility to the terminal. When the local network moves, mobility for the local network is provided. The stability of a network is guaranteed using security connection.

Abstract: Technology for forming a virtual private network (VPN) is provided. A VPN gateway that supports mobility with a connection node having a virtual home address (HoA) and a care of address (CoA) includes a mobility support unit, a data security unit, and a virtual address converter. When a packet is transferred from the connection node, the mobility support unit sustains a binding relationship between a home address (HoA) of the connection node and the changed CoA, and processes a mobility tunnel for the packet, thereby generating a first conversion packet. The data security unit performs a security test of the first conversion packet. The virtual address converter converts the HoA of the connection node, which is a source address of the first conversion packet in which the security test is complete, to a private network internal address that can be used in the VPN, thereby generating a second conversion packet.

Abstract: In order for a peer node to perform direct communication with a correspondent peer node in an Internet protocol network, the peer node receives a virtual address of the correspondent peer node from a server, and then when the peer node can directly set a tunnel with the correspondent peer node, the peer node sets a tunnel with the correspondent peer node, and when the peer node cannot directly set a tunnel with the correspondent peer node, the peer node sets a tunnel with a tunnel repeater. Thereafter, the peer node connects a virtual address of the correspondent peer node as route information to the tunnel. Thereby, a packet using a virtual address of the correspondent peer node as a destination is transmitted to the correspondent peer node through a predetermined tunnel.

Abstract: The present invention relates to tunneling an IPv6 packet through an IPv4 network. In using a tunneling method upon transmitting an IPv6 packet in an IP network, when destination nodes desired to be communicated are located within the same IPv6 prefix network, IPv6 prefix information is added for the management of a tunnel entry. Hence, tunneling information on terminals located within the same IPv6 prefix network can be managed as one tunnel entry. Accordingly, the time consumed when retrieving a tunnel entry can be reduced.

Abstract: A method for providing a service of downloading stereoscopic image data including first image data and second image data in a digital broadcasting system includes: generating information regarding a file name of each of the first image data and the second image data; and transmitting the first image data, the information regarding the file name of the first image data, the second image data, and the information regarding the file name of the second image data. The file name of the second image data includes a prefix indicating the second image data of the stereoscopic image data.

Abstract: Provided is a method for configuring a control tunnel and a direct tunnel in an IPv4 network-based IPv6 service providing system. To provide IPv6 service, when a random request terminal receives a tunnel response message from a control server by using service information downloaded from a portal server at the time of initialization, the request terminal configures a control tunnel with the control server, and is registered to the control server. The request terminal transmits and receives a direct tunnel request message and a direct tunnel response message with a counterpart terminal by using its terminal information learned during the control tunnel configuration, i.e., network position information and status information, thereby configuring a direct tunnel. Thus, IPv6 communication is made through IPv4 based IPv6 tunneling, so that IPv6 application services that are not yet widely used can easily come into wide use.