KR100924428B1 - How to Support Dual Stack in Mobile Internet Network, Address Assignment and Registration Method, Packet Forwarding Method - Google Patents

Abstract

The present invention relates to a dual stack support method, an address allocation and registration method, and a packet forwarding method in a portable internet network. In particular, the dual stack terminal using an IPv4 address and an IPv6 address at the same time in a portable internet network can be disconnected. It is intended to provide a method for supporting IPv4 and IPv6 dual stack, which can provide services that are not available and can reduce the routing load of a home agent (HA) and a control station (ACR).

To this end, the present invention provides a dual stack support method in a portable Internet network, wherein the control station (ACR) is obtained between the ACR and the home agent (HA) by obtaining the IPv4 and IPv6 addresses of the dual stack terminal (MN) Registering with the HA with key information of one tunnel; Assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN; When the downlink traffic to the MN occurs, the HA encapsulates a tunnel header including a transport IP header and the key information in an original packet, and transmits the tunnel header to the ACR based on tunnel endpoint information through the first tunnel. step; Converting, by the ACR, the transport IP header of the encapsulated packet and transmitting it to the RAS via a second tunnel established between the ACR and a base station (RAS) based on the key information of the tunnel header; And the RAS removing (decapsulating) the transport IP header and the tunnel header and transmitting the decapsulated packet to the MN.

Mobile Internet, Dual Stack, IPv4, IPv6, Tunnel

Description

Method for supporting dual stack in wireless broadband access network, address allocation / registration method and packet routing method in its}

The present invention relates to a dual stack support method, an address allocation and registration method for the same, and a packet forwarding method in a portable Internet network.

In particular, the present invention provides a seamless service by ensuring the mobility of the dual stack terminal using the IPv4 (Internet Protocol version 4) address and IPv6 (IP version 6) address in the portable Internet network, and provides a home agent (HA: Home The present invention relates to an IPv4 and IPv6 dual stack supporting method capable of reducing the routing load of an agent and an access control router (ACR).

In addition, the present invention, in order to support IPv4 and IPv6 dual stack, the IPv4 and IPv6 address is assigned to the dual stack terminal using a proxy mobile IP (PMIP: Proxy Mobile IP) [address allocation method], the IPv4 and IPv6 of the terminal Register the address to one home agent [HA address registration method], and the home agent (HA) uses the IPv4 and IPv6 addresses of the terminal to send traffic to the control station (ACR) through the GRE (Generic Route Encapsulation) tunnel. To send (routing) [packet delivery method].

Currently, the Internet environment has a 32-bit class-based addressing (IPv4). Such an address system is difficult to accurately distribute addresses according to demand in the process of allocating Internet addresses. In addition, due to the exponential increase of the IP address due to the exponential growth of the Internet, it is unable to meet the address demands required in the future of mobile communication, home networking, and information appliances. In addition, the IPv4 protocol has limitations in security issues, QoS, and interworking with heterogeneous communication networks that are to be serviced in the future. Therefore, to solve this problem, the IETF developed and announced IPv6 to solve the problem of IPv4 address exhaustion and to accommodate new services. The next generation Internet environment is expected to evolve into an IPv6-based ubiquitous environment, and therefore, it must be able to provide mobility of all nodes including terminals in the existing IPv4 environment.

Therefore, the transition process from IPv4 to IPv6 is expected. In other words, the IPv6 Internet basically means that the IP stack is replaced from IPv4 to IPv6. Until the full transition to IPv6 is made on the Internet, the IPv6 Internet implements both IP4 stacks to use both IPv4 and IPv6. / IPv6 Dual Stack Host 'will be used as the transition to IPv6.

In other words, as the activation of IPv6 proceeds, it will coexist with the existing IPv4 network. In other words, it is virtually impossible to replace many IPv4 nodes (hosts and routers) of the current Internet with IPv6 at once, and will gradually move to the Internet environment by looking for ways to use IPv4 and IPv6 together. Accordingly, in order to be able to service in a mixed network by simultaneously interworking an IPv4 network and an IPv6 network, a dual stack structure having both IPv6 and IPv4 is required.

In this switching process, a terminal using IPv4 and IPv6 dual stacks is inevitably present, and the dual stack terminal communicates with a node of a IPv4 network (CN: Correspondent Node) or an IPv6 network node (CN). Will occur. In this case, the dual stack terminal must be equipped with both an IPv4 application and an IPv6 application, so that communication with the nodes of the IPv4 and IPv6 networks is possible.

In the case of a network device, the router can be implemented as an IPv4 / IPv6 dual stack router. Thus, IPv6 routers are dual stack routers that support both IPv4 and IPv6 by default with IPv4 and with IPv6. However, the large backbone routers used for the backbone may not support IPv4 / IPv6 dual stack. While dual-stack routers are versatile, managing both the IPv4 routing table and the IPv6 routing table from a high-speed routing point of view, and thus handling the routing, creates a significant load increase. Therefore, IPv6-only routers are suitable for backbone routers.

First of all, however, in the portable Internet network, each agent (Agent) separately registers to two corresponding home agents (HA) in the control station (ACR) for IPv4 and IPv6 addresses, and processes traffic, respectively. Although the control station (ACR) can be implemented in a dual stack structure to handle IPv4 and IPv6 traffic, the HA for IPv4 and the HA for IPv6 are required, respectively, and the traffic must be handled separately.

As such, an environment in which IPv4 / IPv6 dual stack hosts, IPv4-only hosts, and IPv6-only hosts coexist is an environment of the IPv6 transition stage.

The conventional method has the following problems when considering the technical characteristics of the portable Internet network.

Separate processing is required depending on whether the IP network connecting the home agent (HA) and the control station (ACR) is an IPv4 or IPv6 network. In addition, since the control station (ACR) manages two HAs (HA for IPv4 and HA for IPv6) for each dual stack terminal, the control station (ACR) has a processing function for traffic classification and analysis for routing processing. This delays packet delivery time. In addition, the home agent (HA) also has a disadvantage in that data is registered between IP addresses instead of users, and data management between two HAs is required for integrated user management.

In addition, in the PMIP (for reference, PMIPv6 supports IPv6 mobility by allowing the MAG (Mobile Access Gateway) to handle mobility on behalf of the terminal even if the terminal does not support mobility by itself), the tunnel between the home agent (HA) and the control station (ACR) (Tunnel) and Tunnel between control station (ACR) and base station (RAS: Radio Access Station) is basically used in mobile Internet network, so processing for encapsulation and decapsulation of packets is required. Therefore, there is a disadvantage that the packet delivery time is delayed.

With this in mind, even in a dual stack that supports IPv4 and IPv6, one home agent (HA) manages users, and between home agents (HA) and control stations (ACR), and control. When using a tunnel between a station (ACR) and a base station (RAS), a method of efficiently delivering a packet (that is, a routing load reduction method of HA and ACR) is essential. Even if the network between the home agent (HA) and the control station (ACR) does not support IPv4 and IPv6 dual stack, it should be able to support the dual stack terminal normally.

Accordingly, the present invention provides a seamless service by ensuring the mobility of the dual stack terminal using the IPv4 address and the IPv6 address simultaneously in the portable Internet network, and can reduce the routing load of the home agent (HA) and the control station (ACR) It is a first object to provide a method for supporting IPv4 and IPv6 dual stack.

Another object of the present invention is to provide an address allocation method for allocating IPv4 and IPv6 addresses to dual stack terminals using proxy mobile IP (PMIP) to support IPv4 and IPv6 dual stack. This is a technical challenge for proxy mobile IP implementations that support IPv4 and IPv6 dual stack.

Another object of the present invention is to provide an address registration method for effectively registering IPv4 and IPv6 addresses of a terminal in one home agent (HA) in order to support IPv4 and IPv6 dual stacks.

In addition, the present invention, in order to support IPv4 and IPv6 dual stack, the home agent (HA) efficiently transmits the downlink traffic to the control station (ACR) through the GRE tunnel using the IPv4 and IPv6 addresses of the terminal (MN) ( A fourth object is to provide a packet forwarding method. This is a technical problem in routing the IPv4 and IPv6 downlink traffic destined for the terminal (MN) in the HA, the downlink traffic delivered to the terminal (MN).

In addition, the present invention, in order to support IPv4 and IPv6 dual stack, the control station (ACR) efficiently transmits the upstream traffic to the home agent (HA) through the GRE tunnel using the IPv4 and IPv6 addresses of the terminal (MN) ( A fifth object is to provide a packet forwarding method. In technical routing of the upstream traffic delivered to the terminal CN in routing the IPv4 and IPv6 upstream traffic destined for the terminal CN in the ACR.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned above can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a terminal address allocation method for supporting dual stack, wherein when a dual stack terminal (MN) is connected, a control station (ACR) uses a proxy mobile IP function to perform IPv4 of the MN. And obtaining an IPv6 address; Through the proxy binding update message, the ACR registers the obtained IPv4 and IPv6 addresses with a home agent (HA), and provides key information of a first tunnel set between the ACR and the HA to support IPv4 and IPv6 of the MN. Registering with the HA; And assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN.

In order to achieve the third object, the present invention provides a method for registering IPv4 and IPv6 addresses obtained by the address assignment method, wherein the IPv4 and IPv6 addresses received from the ACR are stored together with key information of the first tunnel. In addition, the ACR address may be mapped as endpoint information of the first tunnel and managed by one HA.

In accordance with another aspect of the present invention, there is provided a packet forwarding method for supporting dual stack. In the downlink traffic processing, a home agent (HA) transmits a transport IP header to an original packet, and the HA and the control station (ACR). Encapsulating a tunnel header including key information of a first tunnel established between the terminals and transmitting the encapsulated packet to the ACR through the first tunnel based on tunnel endpoint information; The ACR converts the transport IP header of the encapsulated packet and converts the encapsulated packet in which the transport IP header is converted to the ACR and the base station based on the key information of the tunnel header. Transmitting to the RAS through a second tunnel established between the (RAS); And removing, by the RAS, the transport IP header and the tunnel header from the encapsulated packet in which the transport IP header is converted, and transmitting the decapsulated transport IP header and the tunnel header to a mobile terminal (MN). It is characterized by.

In accordance with another aspect of the present invention, there is provided a packet forwarding method for supporting dual stack. In the uplink traffic processing, a base station (RAS) transmits a transport IP header to the original packet of a mobile station (MN) and the 'RAS'. Encapsulating a tunnel header including key information of a first tunnel set between the control station and the ACR, and transmitting an encapsulated packet to the ACR based on the key information of the tunnel header; The ACR converts the transport IP header of the encapsulated packet, and the home agent HA and the encapsulated packet of the transport IP header are converted based on the key information. Transmitting to the HA via a second tunnel established between ACRs; And removing, by the HA, the transport IP header and the tunnel header from the encapsulated packet in which the transport IP header is converted, and transmitting the decapsulated transport IP header and the tunnel header to a counterpart node CN. It is characterized by.

Accordingly, on the basis of achieving the fourth object, the present invention for achieving the first object is, in the dual stack support method in a portable Internet network, the control station (ACR) is the IPv4 of the dual stack terminal (MN) and Obtaining an IPv6 address and registering with the HA together with key information of a first tunnel established between the ACR and a home agent (HA); Assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN; When the downlink traffic to the MN occurs, the HA encapsulates a tunnel header including a transport IP header and the key information in an original packet, and transmits the tunnel header to the ACR based on tunnel endpoint information through the first tunnel. step; Converting, by the ACR, the transport IP header of the encapsulated packet and transmitting it to the RAS via a second tunnel established between the ACR and a base station (RAS) based on the key information of the tunnel header; And the RAS removing (decapsulating) the transport IP header and the tunnel header and transmitting the decapsulated packet to the MN.

In addition, on the basis of achieving the fifth object, the present invention for achieving the first object, in the dual stack support method in a portable Internet network, the control station (ACR) is the IPv4 and IPv6 of the dual stack terminal (MN) Obtaining an address and registering with the HA together with key information of a first tunnel established between the ACR and a home agent (HA); Assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN; Upon generation of upstream traffic from the MN, a base station (RAS) encapsulates a tunnel header including a transport IP header and the key information in the original packet of the MN, and between the RAS and the ACR based on the key information. Transmitting to the ACR through the established second tunnel; The ACR converting the transport IP header of the encapsulated packet, and transmitting the transport IP header to the HA through the first tunnel based on the key information; And removing, by encapsulating, the transport IP header and the tunnel header and transmitting the same to the counterpart node CN.

The present invention as described above, by registering the IPv4 and IPv6 address in one HA, to ensure the mobility of the dual stack terminal supporting IPv4 and IPv6 at the same time to provide a seamless service, GRE tunnel when a traffic occurs for the dual stack terminal This reduces the unnecessary encapsulation process between HA and ACR, ACR and RAS to provide efficient routing.

In addition, the present invention has the effect of reducing the data required for routing information management by using the GRE key, faster routing information retrieval can shorten the packet delivery time.

In addition, the present invention has the effect of supporting the dual stack using only the GRE tunnel regardless of whether IPv4 and IPv6 of the portable Internet network.

The above objects, features, and advantages will become more apparent from the detailed description given hereinafter with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention pertains may share the technical idea of the present invention. It will be easy to implement. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a configuration of a WiBro network to which the present invention is applied.

As shown in FIG. 1, a typical WiBro network includes a mobile terminal (MN) 10 and a mobile terminal (MN) that provide a service through a wireless connection with a base station (RAS) 20. And a base station (RAS) 20 for connecting a radio connection with the network 10 to an IPv4 network and an IPv6 network, and a control station (ACR) 30 for IP access and mobility management.

When transmitting the packet to the mobile terminal (MN) 10 from the outside of the wireless access network, and delivers it to the base station (BS: Base Station) (20,30) through the router (AR: Access Router) 40, the base station (BS) (20, 30) delivers the packet to the mobile terminal (MN) (10).

In the above description, the base station (RAS) 20 and the control station (ACR) 30 may be integrated in one base station apparatus (BS) or may be separately configured.

In a portable Internet network supporting proxy mobile IP, the control station (ACR) 30 supports proxy mobile IPv4 (PMIPv4) or proxy mobile IPv6 (PMIPv6) or PMIPv4 and PMIPv6.

The mobile terminal (MN) 10 is a dual stack terminal using IPv4 and IPv6 addresses.

The control station (ACR) 30 supports IPv4 and IPv6, and supports Proxy Mobile IP (PMIP) in the portable Internet network.

The home agent (HA) 50 supports both IPv4 and IPv6.

Traffic communicated between the terminal 11 and the counterpart nodes 60 and 70 of the IPv4 network and the IPv6 network is always connected to the tunnel 101 between the home agent 50 and the control station 30. It is communicated using a tunnel 102 between a control station (ACR) 30 and a base station (RAS) 20. In this case, the tunnels 101 and 102 use the GRE tunnel method as an example.

In order to support the IPv4 and IPv6 dual stack terminal 10 in the portable Internet network, as shown in FIG. 2, the IPv4 and IPv6 addresses should be allocated to the terminal 10 using PMIP. At this time, the assigned IPv4 and IPv6 addresses must be registered and managed in the same home agent (HA) 50 as shown in FIG. Subsequently, the home agent (HA) 50 transmits IPv4 / to the terminal 10 having IPv4 and IPv6 addresses from the partner nodes 60 and 70 of the IPv4 and IPv6 networks, as shown in FIG. 4. Efficient routing for IPv6 traffic

In the dual stack supporting method according to the present invention, an address allocation process of allocating IPv4 and IPv6 addresses to the MN 10 using PMIP in order to support IPv4 and IPv6 dual stack terminal (MN) 10 in a portable Internet network. [See FIG. 2], an address registration process (see FIG. 3) for registering and managing assigned IPv4 and IPv6 addresses in the same HA 50, and a terminal having IPv4 and IPv6 addresses registered in the CNs 60 and 70. (50) Efficient routing is performed by the HA 50 for downlink traffic transmitted to the MN 10 or upstream traffic transmitted from the terminal 10 having the registered IPv4 and IPv6 addresses to the CNs 60 and 70. It is divided into a packet forwarding process [see FIGS. 4 to 6].

2 is a flowchart illustrating an address allocation process in a dual stack supporting method according to the present invention.

In order to allocate IPv4 and IPv6 addresses of the terminal (MN) 10 in the mobile Internet network, the control station 30 obtains the IPv4 and IPv6 address information of the terminal 10 from the authentication server (AAA) using PMIP, Using the IPv4 and IPv6 address information obtained from the authentication server (AAA), an address is assigned to the terminal (MN) 10, and a home agent (HA) 50 is assigned a GRE key to be used for the terminal's IPv4 and IPv6. Register. Looking at this in detail.

First, the mobile terminal (MN) 10 sends a burst profile, media access control (MAC) information of the terminal, etc. to a control station (ACR) 30 through a ranging request (RNG-REQ) message, The control station 30 responds with a ranging response (RNG-RSP: Ranging Response) message (201). In this case, the RN-RSP message includes information such as ranging status, burst profile, MAC address of the terminal 10, and connection identifier (CID).

After performing the ranging (RNG) process, the mobile terminal 10 transmits a basic capability negotiation request (SBC-REQ) message to the control station 30, and the control station 30 transmits the basic capability. In operation 201, a negotiation response (SBC-RSP: SS Basic Capability Response) message is received to exchange information for using a radio resource. In this case, the SBC message includes a transmission / reception switching time, a maximum power, a current transmission power, and information related to an orthogonal frequency division multiple (OFDM) according to a time division duplex (TDD) scheme of the terminal 10.

After performing the basic capability negotiation (SBC) process, the mobile terminal 10 transmits a privacy key management (PKM) request message to the authentication server (AAA) [EAP transmission request], and receives a PKM response message to protect the information. Manage required encryption keys [EAP Transmission Response] (202). In this process (authentication process), the control station 30 obtains IPv4 and IPv6 address information of the mobile terminal (MN) 10 from the authentication server using PMIP (PMIPv4, PMIPv6) (203). Here, the "RADIUS" or "DIAMETER" protocol is used as a protocol for authentication, and the control station 30 obtains IPv4 and IPv6 address information by using Vendor Specific TLV (Type Length Value) in a message of the authentication protocol. .

After performing the authentication process, the mobile terminal (MN) 10 transmits a Registration Request (REG-REQ) message to the control station (ACR) 30, and the control station (ACR) 30 to this end. ) Transmits a registration response (REG-RSP) message to the mobile terminal 10 (204). At this time, the registration request message includes information such as the number of up / down CIDs, the type of packet (CS: Convergence Sublayer), maximum classification information, and service flow to be used in Internet communication.

After processing the registration message, the control station (ACR) 30 transmits a dynamic service addition (DSA) request message for establishing a traffic connection to the mobile terminal (MN) 10, and the mobile terminal (MN) ( If 10) responds with a DSA-RSP (DSA Response) message, it checks with a DSA Acknowledge (DSA-ACK) message (205). At this time, the DSA message processes the up / down service flow by using the transaction identification number.

After processing the traffic connection establishment, the control station (ACR) 30 stores the IPv4 and IPv6 address information obtained from the authentication server (AAA) in the proxy mobile IP agent (located in the ACR), and the mobile terminal (MN). Instead of sending the binding information to the home agent (HA) 50 via a Binding Update message [Proxy function], the proxy mobile IP agent of the control station (ACR) 30 [MAG] (Mobile Access Gateway)] through the Proxy Binding Update message, the GRE tunnel 101 and the control station (ACR) 30 between the home agent (HA) 50 and the control station (ACR) 30. The key information of the GRE tunnel 102 between the base station (RAS) and the base station (RAS) 20 (hereinafter, referred to as a 'GRE key') is transferred to the home agent (LMA (Local Mobility Anchor)) 50 (206).

At this time, the proxy BU message includes IPv4 and IPv6 address information (IPv4 HoA, IPv6 HoA) set in the mobile terminal (MN) 10, and includes a GRE key for IPv4, a GRE key for IPv6, and a GRE endpoint. (Endpoint) information (ie, IPv4 address of ACR, IPv6 address of ACR) is included. Here, the IPv4 GRE key and the IPv6 GRE key value displayed in the Proxy BU message are the GRE key values used for forwarding downlink traffic. However, when the network between the HA 50 and the ACR 30 supports only IPv4, the IPv4 GRE key and the IPv4 address of the ACR 30 are transmitted as GRE endpoint information. In addition, when the network between the HA 50 and the ACR 30 supports only IPv6, the IPv6 GRE key and the IPv6 address of the ACR 30 are transmitted as the GRE endpoint information. However, when the network between the HA 50 and the ACR 30 supports IPv4 and IPv6, the IPv4 GRE key and the IPv6 GRE key, and the IPv4 address and the IPv6 address of the ACR 30 as the GRE endpoint information are stored. Is sent.

Here, with respect to IPv4, the GRE tunnel key (a) for IPv4 used for the tunnel 101 of the HA 50-ACR 30 is the IPv4 used for the tunnel 102 of the ACR 30-RAS 20. It is the same key value as the GRE tunnel key (b). Also, for IPv6, the GRE tunnel key c for IPv6 used for the tunnel 101 of the HA 50-ACR 30 is the IPv6 used for the tunnel 102 of the ACR 30-RAS 20. It is the same key value as the GRE tunnel key d for use (c = d). That is, the GRE tunnel key value used in the tunnel 102 of the ACR 30-RAS 20 is also used in the tunnel 101 of the HA 50-ACR 30 in the same manner.

Subsequently, the home agent [LMA] 50 transmits an access request message to the authentication server (AAA) to verify the address of the terminal (207), and the authentication server for this sends an access accept message (Access Accept) message. In response (208), the authentication server (AAA) requests to start charging (Accounting Request Start) (209).

The home agent [LMA] 50 transmits a proxy binding acknowledgment message to the control station [MAG] 30 in response to the Proxy BU message (210). At this time, a proxy binding acknowledgment (Proxy BA) message includes a GRE key for IPv4 and a GRE key for IPv6, which are used for forwarding traffic (packet to 'MN → CN'). This is different from the GRE key value used for forwarding downlink traffic [packets sent to 'CN → MN'].

Here, for IPv4, the GRE tunnel key e for IPv4 used for the tunnel 101 of the HA 50-ACR 30 is the IPv4 used for the tunnel 102 of the ACR 30-RAS 20. This is the same value as the GRE tunnel key f (e = f). In addition, for IPv6, the GRE tunnel key g for IPv6 used for the tunnel 101 of the HA 50-ACR 30 is the IPv6 used for the tunnel 102 of the ACR 30-RAS 20. This is the same value as the GRE tunnel key (h). That is, the GRE tunnel key value used in the tunnel 102 of the ACR 30-RAS 20 is also used in the tunnel 101 of the HA 50-ACR 30 in the same manner.

The control station (ACR) 30 then creates GRE tunnels 101, 102 between the RAS 20-ACR 30 and the ACR 30-HA 50 (211, 212).

Next, in case of IPv4 according to the IP version, an IP address to be used by the mobile terminal (MN) 10 is automatically set using DHCP (Dynamic Host Configuration Protocol) v4 (213). In addition, in case of IPv6, an address to be used by the mobile station (MN) 10 is automatically set using DHCPv6 or an automatic configuration function (214).

Here, there are two ways to set an address on a host when IPv6 is introduced. One is 'IPv6 Stateful Address Auto-Configuration' [How to use DHCP technology using address assignment server], and the other is 'IPv6 Stateless Address Auto-Configuration' -Configuration) '[how to configure automatically without address assignment server]. In other words, 'IPv6 Stateful Address Autoconfiguration' is a method by which the Address Management Server assigns an address to a host by DHCPv6 protocol. 'IPv6 Stateless Address Autoconfiguration' is used by the host based on network information. This is how you create an address.

In the above, when using the DHCP protocol, the control station (ACR) 30 performs a DHCP proxy function to intercept and process DHCPv4 and DHCPv6 messages in the middle.

In particular, the mobile terminal (MN) 10 can automatically set IPv4 and IPv6 addresses regardless of whether the mobile IP function is implemented.

FIG. 3 is an exemplary diagram illustrating an address registration process in the dual stack support method according to the present invention, and illustrates information (terminal registration table) of a terminal managed by the home agent (HA) 50.

As described above with reference to FIG. 2, the IPv4 and IPv6 address information (IPv4 HoA, IPv6 HoA) set in the mobile terminal (MN) 10 is transmitted through a home agent (HA) 50 through a proxy binding update (Proxy BU) message. Is registered).

At this time, in addition to the IPv4 and IPv6 address information, the Proxy BU message includes IPv4 / IPv6 key information (GRE key) of the GRE tunnels 101 and 102 between the HA 50 -ACR 30 and the ACR 30 -RAS 20. GRE endpoint information (ie, IPv4 address of ACR, or IPv6 address of ACR, or IPv4 / IPv6 address of ACR) is transmitted together. Here, the GRE endpoint information is transmitted from the source address for transmitting the Proxy BU message, that is, the IPv4 address or the IPv6 address or the IPv4 / IPv6 address of the ACR 30 according to the type supported by the network between the HA 50 and the ACR 30. .

For example, when the network between the HA 50 and the ACR 30 supports only IPv4, the IPv4 GRE key and the IPv4 address of the ACR 30 are transmitted as GRE endpoint information. In addition, when the network between the HA 50 and the ACR 30 supports only IPv6, the IPv6 GRE key and the IPv6 address of the ACR 30 are transmitted as the GRE endpoint information. However, when the network between the HA 50 and the ACR 30 supports IPv4 and IPv6, the IPv4 GRE key and the IPv6 GRE key, and the IPv4 address and the IPv6 address of the ACR 30 as the GRE endpoint information are stored. Is sent.

Accordingly, the home agent HA is an IPv4 HoA 301, an IPv6 HoA 302, an IPv4 GRE key 303, an IPv6 GRE key 304 of the mobile terminal (MN) 10, as shown in FIG. GRE endpoint information 305 is registered and managed.

Here, the GRE tunnel key 303 for IPv4 used in the tunnel 101 of the HA 50-ACR 30 for the IPv4 during the downlink traffic [packet to 'CN → NN'] processing is ACR 30. ) Is the same value as the GRE tunnel key 303 for IPv4 used in the tunnel 102 of the RAS 20. When processing downlink traffic [packet sent to CN → NN], the IPv6 GRE tunnel key 304 used for the tunnel 101 of the HA 50 -ACR 30 is the ACR 30 for IPv6. This is the same value as the GRE tunnel key 304 for IPv6 used for the tunnel 102 of RAS 20. That is, the GRE key of the HA 50 -ACR 30 tunnel and the GRE key of the ACR 30 -RAS 20 tunnel use the same key value, and the GRE key only varies according to IPv4 and IPv6. In the present invention, the GRE tunnel key value used in the tunnel 102 of the ACR 30 -RAS 20 when processing downlink traffic [packet to 'CN → NN'] is processed in the tunnel of the HA 50 -ACR 30. The same applies to (101).

However, the IPv4 / IPv6 GRE tunnel keys 303 and 304 for upstream traffic [packets sent to 'MN → CN'] are the IPv4 / IPv6 GRE tunnel keys (for packet sent to 'CN → NN'] for downstream traffic [packets sent to 'CN → NN']. 303,304). However, also in this case, the IPv4 GRE tunnel key 303 used for the tunnel 101 of the HA 50-ACR 30 for IPv4 is the tunnel 102 of the ACR 30-RAS 20. The same as the GRE tunnel key 303 for IPv4 used for the server, and the GRE tunnel key 304 for the IPv6 used for the tunnel 101 of the HA 50-ACR 30 for IPv6 is ACR 30-RAS. It is the same value as the GRE tunnel key 304 for IPv6 used for the tunnel 102 of (20). That is, the GRE key of the HA 50 -ACR 30 tunnel and the GRE key of the ACR 30 -RAS 20 tunnel are the same, and the GRE key is only changed according to IPv4 and IPv6. In the present invention, the GRE tunnel key value used in the tunnel 102 of the ACR 30-RAS 20 when processing uplink traffic [packet to 'MN → CN'] is processed in the tunnel of the HA 50 -ACR 30. The same applies to (101).

Therefore, the home agent (HA) 50 sends the values of the GRE tunnel key 303 for IPv4 and the GRE tunnel key 306 for IPv6 to the uplink traffic [packets to 'MN → CN'] and the downlink traffic ['CN → NN). Packet sent to '] is managed by processing. However, for processing upstream traffic [packets sent to 'MN → CN'], the home agent (HA) 50 uses a GRE key for IPv4 or a GRE key for IPv6 or IPv4 / IPv6 in a proxy binding acknowledgment (Proxy BA) message. It informs the control station (ACR) 30 of the GRE key value.

In particular, home agent (HA) 50 performs routing of IPv4 and IPv6 packets using IPv4 / IPv6 GRE tunnel keys 303 and 304 and GRE endpoint information (ACR address). At this time, the endpoint information (address of the ACR) uses an IPv4 address or an IPv6 address according to the type supported by the network between the HA 50 and the ACR 30. This determines whether the endpoint of the tunnel is IPv4 or IPv6 according to the transmission address that sends the Proxy BU message.

Hereinafter, a packet forwarding process of the dual stack supporting method according to the present invention will be described with reference to FIGS. 4 to 6.

FIG. 5 shows a case where the network between the HA 50 and the ACR 30 and the ACR 30 and the RAS 20 is IPv4. Through this, a process of encapsulating downlink traffic into an IPv4 GRE or decapsulating upstream traffic into an IPv4 GRE will be described.

In addition, FIG. 6 shows a case where the network between the HA 50 and the ACR 30 and the ACR 30 and the RAS 20 is IPv6. Through this, a process of encapsulating downlink traffic into an IPv6 GRE or decapsulating upstream traffic into an IPv6 GRE will be described.

First, a description will be given of the processing of packets (downstream traffic) sent by the CN (60, 70) to the NN (10).

First, when downlink traffic from the HA 50 to the MN 10 occurs (401), the UE registration table of FIG. 3 is examined (402).

In the UE registration table checking process, it is determined whether the address (HoA) of the UE registered in the HA 50 matches the destination address of the current traffic (403), and if it matches, the endpoint information (ACR) of the corresponding tunnel (Tunnel). Address) and GRE key (GRE key for IPv4, IPv6 GRE key) and find (404), [When the endpoint information and GRE key is found, the terminal registration table check is terminated]. After performing the tunnel (ie, performing GRE encapsulation) (406), the packet is transmitted to the ACR 30 using the tunnel (407). The GRE tunnel used between the ACR 30 and the RAS 20 also delivers the packet using the GRE key information used between the HA 50 and the ACR 30.

In the above, if the address (HoA) of the terminal registered in the HA (50) does not match the destination address of the current traffic, processing through general routing.

Looking at the above process in more detail as follows.

First, when processing the IPv4 downlink traffic, if the network between the HA 50 and the ACR 30 supports only IPv4, the HA 50 transmits a packet to the corresponding ACR 30 based on the GRE endpoint information (ACR address). 5, a transport IP header [(source address: HA address), (destination address: ACR address)] 501 and a GRE header 502 for IPv4 are included in the original IPv4 packet of the CN 60, as shown in FIG. (I.e. encoding) to send (encapsulation).

Subsequently, in transmitting the packet to the RAS 20 based on the GRE key of the GRE header 502, the ACR 30 transmits a transport IP header for IPv4 [(source address: HA address), (Destination address: ACR address)] (501) is converted (that is, (source address: ACR address), (destination address: RAS address)] to be transmitted [encapsulation].

Next, the RAS 20 removes the transport IP header [(source address: ACR address), (destination address: RAS address)] 501 and the GRE header 502 for IPv4 from the message of FIG. 10) (decapsulation).

However, in the IPv4 downlink traffic processing, when the network between the HA 50 and the ACR 30 supports only IPv6, the HA 50 sends a packet to the corresponding ACR 30 based on the GRE endpoint information (ACR address). 6, the transport IP header [(source address: HA address), (destination address: ACR address)] 601 and GRE for IPv6 are sent to the original IPv4 packet of the CN 60, as shown in FIG. The header 602 may be attached (i.e., encoded) and transmitted (encapsulation).

On the other hand, when processing the IPv6 downlink traffic, if the network between the HA 50 and the ACR 30 supports only IPv6, the HA 50 transmits a packet to the corresponding ACR 30 based on the GRE endpoint information (ACR address). 6, a transport IP header [(source address: HA address), (destination address: ACR address)] 601 and a GRE header 602 for IPv4 are included in the original IPv4 packet of the CN 70, as shown in FIG. (I.e. encoding) to send (encapsulation).

Subsequently, in transmitting the packet to the RAS 20 based on the GRE key of the GRE header 602, the ACR 30 transmits a transport IP header for IPv6 [(source address: HA address), (Destination Address: ACR Address)] (601) is converted (that is, (Source Address: ACR Address), (Destination Address: RAS Address)] and transmitted [Encapsulation].

Next, the RAS 20 removes the transport IP header [(source address: ACR address), (destination address: RAS address)] 601 and the GRE header 602 for the IPv4 from the message of FIG. 10) (decapsulation).

However, in the IPv6 downlink traffic processing, when the network between the HA 50 and the ACR 30 supports only IPv4, the HA 50 sends packets to the corresponding ACR 30 based on the GRE endpoint information (ACR address). 5, a transport IP header for IPv4 [(source address: HA address), (destination address: ACR address)] 501 and a GRE header in the original IPv6 packet of the CN 70 as shown in FIG. 502 is sent (ie, encoded) and sent (encapsulation).

On the other hand, although not shown in the figure, when the IPv4 upstream traffic processing, the network between the HA (50) to the ACR 30 supports only IPv4 as follows.

First, the RAS 20 transmits a packet to the ACR 30 based on the GRE key. At this time, as shown in FIG. 5, the transport IP header [(source address: RAS address), (destination address: ACR address)] 501 and the GRE header 502 for IPv4 are included in the original IPv4 packet of the MN 10. Send it (ie, encoding) (encapsulation).

Thereafter, the ACR 30 transmits a packet to the HA 50 based on the GRE key of the GRE header 502. At this time, the transport IP header [(source address: RAS address), (destination address: ACR address)] 501 for IPv4 in the message of FIG. 5 is converted (that is, (source address: ACR address), (destination address). HA address)] [Encapsulation].

Next, the HA 50 removes the transport IP header [(source address: ACR address), (destination address: HA address)] 501 and the GRE header 502 for IPv4 from the message of FIG. 60) (decapsulation).

However, in the above IPv4 upstream traffic processing, if the network between the HA 50 and the ACR 30 supports only IPv6, the ACR 30 is IPv6 in the original IPv4 packet of the MN 10 as shown in FIG. 6. Transport IP header [(source address: ACR address), (destination address: HA address)] 601 and GRE header 602 are attached (that is, encoded) and transmitted (encapsulation).

On the other hand, when processing the IPv6 upstream traffic, the network between the HA (50) and the ACR (30) supports only IPv6 as follows.

First, the RAS 20 transmits a packet to the ACR 30 based on the GRE key. At this time, as shown in FIG. 6, the transport IP header [(source address: RAS address), (destination address: ACR address)] 601 and the GRE header 602 for IPv6 in the original IPv6 packet of the MN 10. Send it (ie, encoding) (encapsulation).

Thereafter, the ACR 30 transmits a packet to the HA 50 based on the GRE key of the GRE header 502. In this case, the transport IP header [(source address: RAS address), (destination address: ACR address)] 601 for IPv6 is converted in the message of FIG. 6, that is, (source address: ACR address), (destination address). HA address)] [Encapsulation].

Next, the HA 50 removes the transport IP header [(source address: ACR address), (destination address: HA address)] 601 and the GRE header 602 for IPv6 from the message of FIG. 70) (Decapsulation).

However, in the above IPv6 upstream traffic processing, if the network between the HA 50 and the ACR 30 supports only IPv4, the ACR 30 is IPv4 in the original IPv6 packet of the MN 10 as shown in FIG. 5. Transport IP header [(source address: ACR address), (destination address: HA address)] 501 and GRE header 502 are attached (that is, encoded) and transmitted (encapsulation).

By doing so, it can handle IPv4 and IPv6 up / down traffic, and the network between HA 50 and ACR 30 can efficiently route IPv4 and IPv6 up / down traffic regardless of whether IPv4 or IPv6 is supported. do.

In FIG. 5, when the network between the HA 50 and the ACR 30 and the network between the ACR 30 and the RAS 20 is IPv4, an encapsulation or decapsulation process is performed using an IPv4 GRE. The transport IP header 501 encodes / decodes IPv4 irrespective of the inner packet, thereby processing IPv4 and IPv6 traffic in one HA 50 without additional procedures. At this time, the GRE header 502 uses a GRE key (see FIG. 7).

In addition, in FIG. 6, when the network between the HA 50 and the ACR 30 and the network between the ACR 30 and the RAS 20 is IPv6, an encapsulation or decapsulation is performed using an IPv6 GRE. In the process, the transport IP header 601 encodes / decodes IPv6 irrespective of the inner packet, thereby processing IPv4 and IPv6 traffic in one HA 50 without additional procedures. At this time, at this time, the GRE header 502 uses a GRE key (see Fig. 7).

Referring to FIG. 7, the header format of the GRE tunnels 101 and 102 used between the HA 50 and the ACR 30 and between the ACR 30 and the RAS 20 is illustrated. In order to use the tunnel header efficiently, the GRE tunnel 101 is used between the HA 50 and the ACR 30 and the GRE tunnel key used for the GRE tunnel 102 between the ACR 30 and the RAS 20. 701 is used identically. In other words, the GRE tunnel key value used for the tunnel 102 of the ACR 30-RAS 20 is equally used for the tunnel 101 of the HA 50-ACR 30.

On the other hand, the method of the present invention as described above can be written in a computer program. And code and code segments constituting the program can be easily inferred by computer programmers in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used in the portable Internet network.

1 is a configuration example of a portable Internet (WiBro) network to which the present invention is applied,

2 is a flowchart illustrating an address allocation process in a dual stack supporting method according to the present invention;

3 is a diagram illustrating an embodiment of an address registration process in a dual stack support method according to the present invention;

4 is a flowchart illustrating an embodiment of a packet forwarding process in a dual stack support method according to the present invention;

5 illustrates a process of encapsulating downlink traffic into an IPv4 GRE or decapsulating upstream traffic into an IPv4 GRE when the network between HA and ACR and ACR and RAS is IPv4 in the dual stack supporting method according to the present invention. An illustration showing one embodiment,

6 is encapsulated downlink traffic to IPv6 GRE or decapsulates upstream traffic to IPv6 GRE when the network between HA and ACR and ACR and RAS is IPv6 in the dual stack supporting method according to the present invention. Illustrative diagram of an embodiment showing the process of migration;

7 is a diagram illustrating an embodiment of a header format of a GRE tunnel used between HA and ACR and between ACR and RAS in a dual stack support method according to the present invention.

* Explanation of symbols for the main parts of the drawings

10: mobile terminal (MN) 20: base station (RAS)

30: control station (ACR) 40: router (AR)

50: home agent (HA) 60, 70: partner node (CN)

10,102: GRE tunnel

Claims (20)

In the terminal address allocation method for dual stack support, When the dual stack terminal (MN) is connected, the control station (ACR) using the proxy mobile IP function to obtain the IPv4 and IPv6 addresses of the MN; Through the proxy binding update message, the ACR registers the obtained IPv4 and IPv6 addresses with a home agent (HA), and provides key information of a first tunnel set between the ACR and the HA to support IPv4 and IPv6 of the MN. Registering with the HA; And Assigning the obtained IPv4 and IPv6 addresses to the MN by the ACR; Address assignment method comprising a. The method of claim 1, The first tunnel is a Generic Route Encapsulation (GRE) tunnel between the ACR and the HA. And the key information of the first tunnel is an IPv4 or IPv6 GRE key. The method of claim 2, The proxy binding update message is And the obtained IPv4 and IPv6 addresses, an IPv4 and / or IPv6 GRE key for downstream traffic processing, and an address of the ACR as endpoint information of the first tunnel. The method of claim 3, The endpoint information is, And an IPv4 and / or IPv6 address of the ACR according to a type supported by the network between the ACR and the HA. The method of claim 3, The IPv4 or / and IPv6 GRE key, And the same value as the key information of the second tunnel established between the ACR and the base station (RAS). The method of claim 3, The HA, In response to the proxy binding update message, an IPv4 or / and IPv6 GRE key for upstream traffic processing in a proxy binding acknowledgment message and transmitted to the ACR. The method according to any one of claims 1 to 6, The ACR, Registering the obtained IPv4 and IPv6 addresses to the HA through a proxy mobile IP agent and assigning the obtained IPv4 and IPv6 addresses to the MN through a DHCP (Dynamic Host Configuration Protocol) proxy function. Way. The method of claim 7, wherein The MN is, An address assignment method, characterized in that IPv4 and IPv6 addresses can be set automatically regardless of whether the mobile IP function is implemented. In the method of registering the IPv4 and IPv6 address obtained by the address assignment method of any one of claims 1 to 6, The IPv4 and IPv6 addresses received from the ACR are mapped to key information of the first tunnel and ACR addresses as endpoint information of the first tunnel and managed by one HA. In the packet forwarding method for dual stack support, During downlink traffic processing, the home agent (HA) encapsulates a transport IP header and a 'tunnel header including key information of a first tunnel established between the HA and the control station (ACR)' in an original packet. Transmitting the migrated packet to the ACR through the first tunnel based on tunnel endpoint information; The ACR converts the transport IP header of the encapsulated packet and converts the encapsulated packet in which the transport IP header is converted to the ACR and the base station based on the key information of the tunnel header. Transmitting to the RAS through a second tunnel established between the (RAS); And The RAS removes (decapsulates) the transport IP header and the tunnel header from the 'encapsulated packet in which the transport IP header is converted' and transmits the decoded packet to the mobile terminal (MN). Packet forwarding method comprising a. The method of claim 10, The HA, Regardless of the type of the received packet, the packet forwarding method according to the type supported by the network between the HA and the ACR encapsulates the transport IP header and transmits the packet to the ACR. The method of claim 11, The tunnel endpoint information is Packet forwarding method characterized in that the IPv4 or / and IPv6 address of the ACR according to the type supported by the network between the ACR and the HA. In the packet forwarding method for dual stack support, In the uplink traffic processing, the base station RAS encapsulates the transport IP header and the 'tunnel header including the key information of the first tunnel set between the RAS and the control station (ACR)' in the original packet of the mobile station (MN). Transferring the encapsulated packet to the ACR based on the key information of the tunnel header; The ACR converts the transport IP header of the encapsulated packet, and the home agent HA and the encapsulated packet of the transport IP header are converted based on the key information. Transmitting to the HA via a second tunnel established between ACRs; And The HA removes (decapsulates) the transport IP header and the tunnel header from the 'encapsulated packet in which the transport IP header is converted' and transmits the decapsulated packet to the counterpart node CN. Packet forwarding method comprising a. The method of claim 13, The ACR is, Regardless of the type of the received packet, the packet forwarding method according to the type supported by the network between the HA and the ACR encapsulates the transport IP header and transmits the packet to the HA. The method according to any one of claims 10 to 14, The packet, Packet forwarding method, characterized in that either IPv4 packet or IPv6 packet. The method of claim 15, The first and second tunnels are GRE (Generic Route Encapsulation) tunnels, The key information is a packet forwarding method, characterized in that the IPv4 and / and IPv6 GRE key. In the dual stack support method in the mobile Internet network, Obtaining, by a control station (ACR), IPv4 and IPv6 addresses of a dual stack terminal (MN) and registering the HA with key information of a first tunnel established between the ACR and a home agent (HA); Assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN; When the downlink traffic to the MN occurs, the HA encapsulates a tunnel header including a transport IP header and the key information in an original packet, and transmits the tunnel header to the ACR based on tunnel endpoint information through the first tunnel. step; Converting, by the ACR, the transport IP header of the encapsulated packet and transmitting it to the RAS via a second tunnel established between the ACR and a base station (RAS) based on the key information of the tunnel header; And The RAS removing (decapsulating) the transport IP header and the tunnel header and transmitting the decapsulated packet to the MN Dual stack support method comprising a. In the dual stack support method in the mobile Internet network, Obtaining, by a control station (ACR), IPv4 and IPv6 addresses of a dual stack terminal (MN) and registering the HA with key information of a first tunnel established between the ACR and a home agent (HA); Assigning, by the ACR, the obtained IPv4 and IPv6 addresses to the MN; Upon generation of upstream traffic from the MN, a base station (RAS) encapsulates a tunnel header including a transport IP header and the key information in the original packet of the MN, and between the RAS and the ACR based on the key information. Transmitting to the ACR through the established second tunnel; The ACR converting the transport IP header of the encapsulated packet, and transmitting the transport IP header to the HA through the first tunnel based on the key information; And The HA removes (decapsulates) the transport IP header and the tunnel header and transmits them to a counterpart node CN. Dual stack support method comprising a. The method of claim 17 or 18, The HA and the ACR, Regardless of the type of packets received, the dual stack support method of encapsulating and transmitting the transport IP header according to the type supported by the network between the HA and the ACR. The method of claim 19, The packet, Is either an IPv4 packet or an IPv6 packet, The first and second tunnels are GRE (Generic Route Encapsulation) tunnels, Wherein the key information is an IPv4 or IPv6 GRE key.

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