KR20020028635A - Method for accepting mobile ip in mpls network - Google Patents

Abstract

PURPOSE: A method for accepting a mobile IP in an MPLS(Multi-Protocol Label Switching) network is provided to make MPLS interworked with a mobile IP by combining a mobile IP registration message with MPLS label distribution and to prevent an abuse of headers by utilizing 2-layer tunneling, not 3-layer encapsulation, in tunneling an IP packet in a service network. CONSTITUTION: In configuring a service packet network for IMT-2000 service, an MPLS network accepting a mobile IP is suggested. Under this structure, a topology driven label distribution method and an MIP registration request driven label distribution method are presented. Accordingly, the MPLS network accepting the mobile IP doesn't require 3-layer IP header for transmission to an external agent in tunneling in a network, as compared with a simple combination structure of the mobile IP and the MPLS network.

Description

Method for accepting mobile IP in MPLS network {Method for accepting mobile IP in MPLS network}

The present invention relates to a method of receiving a mobile IP in a multi-protocol label switching (MPLS) network and a computer-readable recording medium recording a program for realizing the method. (IMT-2000) In constructing a service packet network for the International Mobile Telecommunication-2000 (MPT) service, the MPLS which is combined with the Multi-Protocol Label Switching (MPLS) to accommodate the mobile IP, enables the MPLS and the mobile IP to interwork. The present invention relates to a method for accommodating mobile IP in a network and a computer-readable recording medium recording a program for realizing the method.

Here, the IMT-2000 should be able to provide a mobile internet service. In other words, the IMT-2000 includes multimedia services, not limited to voice exchange, in the types of services supported. Most of these multimedia services are based on IP packet exchange, and the development of IP switched packet switching network for IMT-2000 service is an essential condition for providing multimedia services. In order to provide a service to a user, the packet switched network should be configured in the same management network type, which is composed of one service network having an interface with a wireless network and an interface with the Internet. Therefore, in order to construct a packet network for a mobile Internet service, a service network that is subject to the same management that functions as an interface with a wireless network and an interface with the Internet should be able to be constructed. Must be able to support IP

At present, many efforts are being made to build a service network to support such mobility. In particular, the service network becomes a backbone network between mobility agents supporting mobility of users in terms of mobility, and for this purpose, a service network must be able to provide excellent speed and scalability. However, although the service network can be configured with MPLS (Multi-Protocol Label Switching), which is being standardized by the Internet Engineering Task Force (IETF), the IETF MPLS standard does not present a plan to specifically support the mobility of nodes. .

Conventionally, in constructing a service network supporting mobility, no efforts have been made in connection with the structure of a transport network when using mobile IP. For example, in the construction of a service packet network, an ATM (Asynchronous Transfer Mode) switch supporting MPLS that can be exchanged through cell switching has been configured, and mobile IP has been applied as it is without any change in the MPLS structure. . An example thereof will be described in detail with reference to FIG. 1.

1 is a diagram illustrating a packet processing procedure according to a simple combination of a conventional mobile IP and an MPLS network.

As shown in FIG. 1, a first incoming packet finds a care of address (COA) where an IP destination is located by referring to a mobility binding list. When a referral address is found, a forwarding equivalence class (FEC) classification is performed. At the same time, a label capable of being transmitted through a label exchange path (LSP) with a caretaker address as a destination is selected, and then a packet is transmitted by mapping the classified forwarding equivalence class to the selected label.

At this time, the structure of the header by a simple combination may include an IP header for the destination host, an IP header for the care-of address, and an MPLS header for transmission in the MPLS domain. For ATM, a cell header is added.

Therefore, in the conventional MPLS network, when the mobile IP is applied, the packet header of the third layer is additionally added for tunneling to support mobility in the case of IP and mobile IP of three or more layers, and the second layer is transmitted to the MPLS exchange. Packets have been exchanged by adding a cell header. This does not take into account the characteristics of mobile IP in the MPLS network, and there is a problem that causes a delay due to transmission inefficiency and additional processing due to header abuse, duplication of functions of the second and third layers.

The present invention has been made to solve the above problems, by combining the registration message and the MPLS label distribution of the mobile IP to enable the MPLS and mobile IP interworking, when tunneling IP packets in the network (service network) By using tunneling of layer 2 (ATM layer) rather than encapsulation of layer 3 (IP layer), header abuse is prevented, and packets flowing into the home agent (HA) are delayed in the mobility binding list. The purpose of the present invention is to provide a method of accommodating mobile IP in a multi-protocol label switching (MPLS) network that can efficiently accommodate mobile IP by reducing the number of mobile IPs, and a computer-readable recording medium recording a program for implementing the method. have.

1 is an explanatory diagram for a packet processing procedure according to a simple combination of a conventional mobile IP and an MPLS network.

2 is a diagram illustrating an embodiment of an MPLS network for accepting mobile IP according to the present invention;

3 is a diagram illustrating an embodiment of a label distribution method based on a MIP registration request for a mobile IP reception method in an MPLS network according to the present invention;

4 is a diagram illustrating an embodiment of a topology-based label distribution method for a mobile IP acceptance method in an MPLS network according to the present invention.

FIG. 5 is a diagram illustrating an embodiment of a packet processing process of a home agent for a method of receiving mobile IP in an MPLS network according to the present invention. FIG.

The present invention for achieving the above object is, in the mobile IP (IP) acceptance method applied to the Multi-Protocol Label Switching (MPLS) network, and the forwarding equivalence class (FEC) classified by the mobile IP registration message and Mapping a label capable of being transmitted to the care address; And a second step of adding a label mapped to the classified equivalent forwarding class and transmitting the packet to a home agent to an external agent.

In addition, the present invention provides a multi-protocol label switching (MPLS) system having a processor, a function of mapping a label that can be transmitted to a forwarding equivalence class (FEC) classified by a mobile IP registration message and a care address; And a computer readable recording medium having recorded thereon a program for realizing a function of adding a label mapped to the classified equivalent forwarding class and transmitting the packet to a home agent to an external agent.

The present invention relates to a structure and procedure of a network for accommodating mobile IP for supporting a user's mobility in packet switching in constructing a service packet network for an IMT-2000 service. Here, the network structure allows the agent to efficiently operate through the structure in which the physical network structure correspondence method and function are mapped to accommodate the mobile IP. This structure provides easy acceptance of technology based on the standardization process currently underway in the MPLS Working Group (WG), and can be used as a packet network for IMT-2000 service with rapid expansion of technology.

That is, the present invention combines the characteristics of the mobile IP with the MPLS network to enable mutually efficient interaction. In addition, compared to MPLS and mobile IP simple combination that does not accommodate the characteristics of mobile IP, the present invention can reduce the IP encapsulation of the three layers to increase the transmission efficiency compared to the simple combination, thereby reducing processing loss and delay It also provides advantages that can reduce the search delay of mobility binding list in Mobile IP. As a result, these advantages can compensate for the requirements for quality of service (QoS) guarantees and delay-sensitive IMT-2000 services.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is an embodiment configuration diagram of an MPLS network for accommodating mobile IP according to the present invention, and is applicable to a service packet network for an IMT-2000 service, and applies an agent function to a border router.

As shown in FIG. 2, a service network has an interface with the Internet and an interface with a wireless network as a network to which the same management is applied.

The switch of the MPLS network is divided into a label boundary router (LER) and a label switching router (LSR) according to its functions and characteristics. Here, when looking at the function of each router, the label boundary router (LER) performs the role of the interface with the outside and classify the incoming packets to perform the policy, and at the same time transmits to other boundary routers in the MPLS domain. . In the case of a label switching router (LSR), a simple fast switching is performed by using a label for a packet (cell in ATM based case) transmitted from a label boundary router (LER). That is, the Label Switching Router (LSR) checks the input label without performing a special policy for incoming packets from the outside and only exchanges them. In the case of mobile IP, a mobility agent is required, and in order to support mobility of a host, tunneling between mobility agents is performed including additional addresses. In this case, tunneling in mobile IP is meaningful only between agents, and intermediate routers perform no procedures other than exchanging packets. As a result, in FIG. 2, in configuring an MPLS network that accommodates mobile IP, a home agent (HA) and a foreign agent (FA) of a mobility agent are placed in a label boundary router (LER), and routers between agents. Is defined as a Label Switched Router (LSR) that performs only simple fast switching.

Accordingly, the service packet network has an interface with a wireless network and the Internet, where FIG. 2 applies a home agent (HA) to a label boundary router (LER) having an interface with the Internet, and a label having an interface with the wireless network. Apply an external agent (FA) to the border router (LER).

FIG. 3 is a diagram illustrating an MIP registration request based label distribution method for a mobile IP acceptance method in an MPLS network according to the present invention. FIG. 3 shows an MPLS label during an MPLS operation associated with a mobile IP in an MPLS network that accommodates a mobile IP. A mobile IP registration request driven label distribution scheme in which distribution is combined with a mobile IP registration message.

As shown in FIG. 3, the external agent FA transmits a mobile IP registration request message, which is a control message for performing mobility binding, to the home agent HA (31). The home agent (HA) receiving the mobile IP registration request message performs a forwarding equivalence class (FEC) classification based on the home address (32). Then, the home agent (HA) distributes the label to the label switched path (LSP) between the home agent and the external agent while sending a MIP registration reply to the external agent FA (33). ). Finally, the home agent HA performs mapping between the label that can be transmitted to the external agent FA and the forwarding equivalence class (34). Here, the label distribution may constitute an extended form of the MIP registration message or may be a label distribution protocol (LDP).

FIG. 4 is a diagram illustrating a topology-based label distribution method for a mobile IP acceptance method in an MPLS network according to the present invention. FIG. 4 is a diagram illustrating MPLS label distribution during an MPLS operation associated with mobile IP in an MPLS network that accommodates mobile IP. A topology driven label distribution performed by a three-layer routing protocol is shown.

As shown in Fig. 4, this is a layer 3 routing protocol that distributes labels and is not directly related to the mobile IP registration message. The labels are all distributed according to the topology of the network to each agent (41), and the MIP registration request message is received (42). At the same time, the home agent (HA) forwards an equivalent class based on the home address among the received registration messages. A forwarding equivalence class (FEC) classification is performed, and a mapping between a label that can be transmitted to an external agent (FA) and a forwarding equivalence class is performed (43). Thereafter, the home agent HA sends a MIP registration reply message to the external agent FA (44).

FIG. 5 is a diagram illustrating an embodiment of a packet processing process of a home agent for a method for accepting a mobile IP in an MPLS network according to the present invention.

As shown in FIG. 5, in the MPLS network that accommodates mobile IP, a label capable of being transmitted to a forwarding equivalent class and a care-of address is mapped by a MIP registration request message as shown in FIGS. 3 and 4. Therefore, when a packet flows into the home agent HA, the home agent HA does not search the mobility binding list by adding and transmitting a label mapped to the classified forwarding equivalence class (FEC).

In this case, when looking at the structure of the header, the IP header for transmission to the care-of address is not included. Since the tunneling to the agent is performed at Layer 2, the IP header for the destination host and the MPLS for transmission in the MPLS domain Only the header (or cell header in the case of ATM) is needed.

As described above, the present invention proposes an MPLS network for accommodating mobile IP in constructing a service packet network for an IMT-2000 service, and in this structure, a topology-based label distribution method capable of operating with support of the MPLS network. And label distribution based on MIP registration request. Therefore, compared to the simple combined structure of the mobile IP and the MPLS network, the MPLS network that accommodates the mobile IP does not add a three-layer IP header for transmission to an external agent in tunneling in the network. This increases the transmission efficiency by reducing the header / pure data ratio, and reduces the processing cost and delay due to the addition of an IP header for transmission to an external agent.

Meanwhile, in the case of a simple coupling structure, the mobile agent refers to a forwarding information base (FIB) and a label information base (LIB: Label Information Base) after referring to a mobility binding list for tunneling to an external agent. During the registration process, preparation for tunneling has already been completed so that tunneling can be performed by referring to only the forwarding information base and the label information base without referring to the mobility binding list.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention does not add a three-layer IP header for transmission to an external agent, thereby increasing transmission efficiency by reducing a ratio of header / pure data, and according to the addition of an IP header for transmission to an external agent. Processing costs and delays can be reduced, and preparation for tunneling is already completed during the MIP registration process. Therefore, tunneling can be performed only by referring to the forwarding information base and the label information base without referring to the mobility binding list.

Accordingly, the present invention can be used not only as a basic structure of a service packet network for the mobile Internet in IMT-2000 that performs interworking with the wireless network and the internet, but also supports mobile IP in the global Internet. There is an effect that can also be used as a backbone network (Internet Service Provider) ISP.

Claims (5)

In the mobile IP (IP) acceptance method applied to the Multi-Protocol Label Switching (MPLS) network, A first step of mapping a forwarding equivalence class (FEC) classified by the mobile IP registration message and a label capable of being transmitted to the care of address; And A second step of adding a label mapped to the classified equal forwarding class and transmitting the packet to a home agent to an external agent Mobile IP acceptance method comprising a. The method of claim 1, The first step is, Transmitting a mobile IP registration request message, which is a control message for performing mobility binding, to a home agent (HA); A fourth step of the home agent (HA) receiving the mobile IP registration request message performing a forwarding equivalence class (FEC) classification based on a home address; After performing the forwarding equivalence class classification, a label is distributed to a label switched path (LSP) between the home agent and an external agent while simultaneously transmitting a mobile IP registration reply message to an external agent (FA). A fifth step; And A sixth step of the home agent distributing the label to perform mapping between a label that can be transmitted to the foreign agent and a forwarding equivalence class Mobile IP acceptance method comprising a. The method of claim 2, The label distribution is, Mobile IP acceptance method characterized in that configured in the extended form of the mobile IP registration message or a label distribution protocol (LDP). The method of claim 1, The first step is, A third step of distributing a label according to the topology of the network to each agent without destination being directly related to the mobile IP registration request message; After the label distribution, the mobile IP registration request message is received and a forwarding equivalence class (FEC) classification is performed based on a home address among registration messages received by a home agent (HA), and an external agent ( Performing a mapping between a label capable of being transmitted to FA) and a forwarding equivalent class; And A fifth step of transmitting a mobile IP registration reply message to the foreign agent FA after performing the mapping; Mobile IP acceptance method comprising a. In a multi-protocol label switching (MPLS) system with a processor, A function of mapping a forwarding equivalence class (FEC) classified by a mobile IP registration message and a label capable of being transmitted to a care of address; And When a packet flows into a home agent, a function that adds a label mapped to the classified equal forwarding class and transmits it to an external agent A computer-readable recording medium having recorded thereon a program for realizing this.