External header conversion communication device and communication network

Abstract

To achieve a rapid movement registration by configuring a mobile host to perform a movement registration not only with respect to a source but also an immediately preceding transfer point.SOLUTION: In addition to prior art in which a packet addressed to a mobile host is encapsulated in a source and is transferred to a destination, a destination address of an external header is transferred by converting it from a previous transfer point to a current transfer point at the previous transfer point. Although a movement registration is performed with respect to a source in prior art, a destination address conversion of the external header is made possible by performing it with respect to the previous transfer point.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to path control of data networks such as the Internet, intranet, IP telephone network, mobile telephone network, and cloud network.

Background Art

[0002] These networks use the Internet Protocol of IPv4 or IPv6. These communications are performed in units called IP packets or datagrams. And the technology for delivering a datagram to a destination is called path control.

[0003] Path control is essential not only when the communication partner is fixed but also when it moves. Especially when it moves, it is necessary to follow the movement, and a technology for this is required. Also, the same applies to virtual environments such as virtual machines in the cloud. Usually, a virtual machine virtually exists on a specific server, but for some reason or due to a hardware failure, it may move to a different server, which is called migration.

[0004] FIG. 1 is a diagram for explaining a conventional mobile host technology described in RFC3344, IP Mobility Support. In this figure, when not moving, the Mobile Node belonging to the Home Agent moves, moves to Foreign Agent #1, and further shows the state of moving to Foreign Agent #2. When the Mobile Node does not move, it exists in the network to which the Home Agent is connected. The communication partner sends a packet to the Mobile Node. In FIG. 1, the packet indicated by P1 is this packet. This packet passes through the Home Agent. When the Mobile Node is not moving, the Home Agent directly forwards the packet to the Mobile Node. When the Mobile Node moves, the Mobile Node learns the address of the Foreign Agent to which it is connected, and notifies and registers that address and its own address with the Home Agent. Through this notification, called a Binding update, the Home Agent learns that it can send packets destined for the Mobile Node via the notified Foreign Agent. This learned content is stored in the table shown as T1 in FIG. 1. Upon receiving a packet sent from a communication partner to the Mobile Node, the Home Anent encapsulates and forwards the packet to the Foreign Agent to which the Mobile Node is connected at that time. In FIG. 1, the packet of P3 is the packet that is encapsulated and forwarded. In this figure, the Mobile Node has moved to the network under Foreign Agent #3. Foreign Agent #3 extracts the encapsulated packet and forwards it to the Mobile Node.

[0005] The above technology is a basic technology. For example, in a mobile phone network, the GPRS Tunneling Protocol (GTP) is used. The IP packets that the user communicates are encapsulated with a GTP header and further encapsulated with ATM cells or UDP / IP. Although the use of the GTP header is different, the point that it is a tunneling technology is the same. There is also a technology that realizes the part encapsulated or transferred through a tunnel with source routing, which is described in, for example, draft-rekhter-lsr-mobile-hosts-00.txt, “Loose Source Routing for Mobile Hosts”. Also, in the cloud or the like, the movement of virtual machines is targeted, and GRE or the like that can encapsulate L2 frames is used. GRE is described in RFC1701, “Generic Routing Encapsulation (GRE)”. These technologies, in general, are tunneling technologies and can be said to be technologies that follow movement in a virtual circuit. And generally, the path from the end point that encapsulates the capsule to the end point that removes the capsule is carried on the shortest path based on the IP address assigned to the encapsulating end point.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, if the movement continues and the distance between the Mobile Node and the Home Agent increases, the delay time increases, so that the Binding update cannot keep up, and there is a possibility that the number of cases where the packet encapsulated and transferred to the previous Foreign Agent cannot be received increases, which is a problem. An object of the present invention is to reduce the time associated with updates and reduce packet discard by enabling destination updates at points other than the encapsulation point.

Means for Solving the Problems

[0009] Figure 2 is a diagram for showing the inventive principle of the present invention. The Mobile Node has moved from the Home Network, and after moving to the network under Foreign Agent #1, it has moved to the network under Foreign Agent #2. The communication partner sends a packet to the Mobile Node. P1 in Figure 2 corresponds to this packet.

[0010] The Home Agent that has received this packet encapsulates this packet and transfers it to the Foreign Agent. When moving from the Home Network to Foreign Agent #1, FA1 is set as the destination in the external header. P2 in Figure 2 corresponds to this packet. The Home Agent manages T1 in Figure 2, which is a table for managing the movement, and resolves the destination of the encapsulated packet.

[0011] When the Mobile Node further moves to the Foreign Agent #2, in the prior art, the destination of the encapsulated external header sent from the Home Agent is set to FA2. In contrast, in the present invention, the Foreign Agent #1 rewrites the external header of the received encapsulated packet addressed to FA1 to FA2 and forwards it. P3 in FIG. 1 corresponds to this packet. The Foreign Agent #1 manages T2 in FIG. 2, which is a table for managing mobility.

[0012] At this time, to identify the packet to be converted, examine the inner header of the encapsulated packet. If the destination is the MN, convert the destination of the encapsulated external header from FA1 to FA2 and forward it. The Mobile Node that has moved to the network under the Foreign Agent #2 sends a Binding update to the Foreign Agent #1. In the prior art, it is sent to the Home Agent.

Advantages of the Invention

[0013] In the prior art, the Binding update is always sent to the Home Agent, but in the present invention, it is sent to the previous Foreign Agent before the movement. Therefore, since it is sent to an Agent closer from the perspective of the Mobile Node, the propagation time is reduced, and the registration of the movement can be performed quickly.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] It is realized by a process of retrieving based on the header information of the packet, obtaining the destination information of the external header to be converted, and using that information to convert the destination information of the external header. This is realized by using a table for storing internal header information for obtaining the destination information of the external header and searching this table.

EXAMPLE

[0016] FIG. 3 is an example diagram of the present invention. It is composed of a packet receiving unit, a packet transmitting unit, an internal header and external header information extraction unit, an external header rewriting unit, a table search unit, and a table. Depending on the technology for encapsulation, the configuration of the table is different, and the configuration of the table is described corresponding to claims 3, 4, and 5.

[0017] FIG. 4 is a diagram showing a configuration example of a table when the external header and the internal header are IPv4 or IPv6, and is a diagram corresponding to claim 3. It includes the case where the external header is IPv6 and the internal header is IPv6, the case where the external header is IPv6 and the internal header is IPv4, the case where the external header is IPv4 and the internal header is IPv6, and the case where the external header is IPv4 and the internal header is IPv4. Also, an example including the port numbers of TCP and UDP as internal header information is illustrated. Although not included in this figure, for example, a table configuration including the FlowLabel field of the IPv6 header may be adopted.

[0018] FIG. 5 is a diagram showing a configuration example of a table when the external header and the internal header are IPv4 or IPv6 or Ethernet (registered trademark), and is a diagram corresponding to claim 4.

[0019] FIG. 6 is a diagram showing a configuration example of a table when the external header and the internal header are IPv4 or IPv6 or GTP, and is a diagram corresponding to claim 5. In this example, an example including the port numbers of TCP and UDP is illustrated.

Industrial Applicability

[0020] As described above, according to the present invention, since it is possible to quickly respond to movement, it is expected that when further moving from a designated destination, the case where packets have to be discarded can be reduced.

[0021] In addition, policy routing and the like that transmit packets on different routes by specifying different destinations by encapsulation without changing the information of the packets that meet specific conditions can also be realized, which greatly contributes to the sound development of the Internet.

Explanation of Signs

[0022] P Packet T Table

Claims

1. A communication device, characterized by generating or modifying information of an external header of an encapsulated packet based on information of an internal header and the external header.

2. A communication network that, in an encapsulated packet, only converts information of the external header without making changes to the encapsulated packet.

3. The communication device and the communication network according to Claims 1 and 2, characterized in that the external header and the internal header are IPv4 or IPv6.

4. The communication device and the communication network according to Claims 1 and 2, characterized in that the external header and the internal header are IPv4 or IPv6 or Ethernet (registered trademark) or IEEE 802.3 or IEEE 802.

11.

5. The communication device and the communication network according to Claims 1 and 2, characterized in that the external header and the internal header are IPv4 or IPv6 or GTP.

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