JP3385186B2 - Packet routing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet routing device, and more particularly to a technique for suitably routing an IP packet based on data transmitted / received to / from a mobile terminal.

[0002]

2. Description of the Related Art One of systems for routing packets transmitted and received by mobile terminals on a network is disclosed in JP-A-7-
There is one disclosed in Japanese Patent No. 170286. The system according to this conventional example will be described below.

FIG. 7 is a block diagram of the above-mentioned conventional system, in which 101 is an OSPF backbone network, 102 is a home network, 103 is a new area network, and 104 is another area network. 105 is a mobility support boundary router (MSBR),
Reference numeral 106 denotes a mobility support router (MSR). A fixed host (SH) data processing device and a data processing (DP) device (not shown) are connected to the home network 102, the new area network 103, and the separate area network 104. In addition, in this system, a mobile host (MH) data processing device (mobile terminal) (not shown) is connected to these networks 102, 10
It moves between 3, 104 and is communicatively connected to any of the networks.

As shown in FIG. 1, in the system according to this conventional example, the home network 102 is connected to at least one mobility support boundary router (MSBR) 105a connected to the OSPF backbone network 101.
It is configured to include. Similarly, the new area network 103 is the OSPF backbone network 101.
At least one MSBR 105b connected between
It is configured to include. Further, another area network 104, which is the third network, is connected to the OSPF backbone network 101 and MSBR 105.
It is configured to include c. The mobile host (MH) data processor can then move between three or more networks and continue to communicate with all other fixed or mobile data processors that are coupled to those networks.

Here, the first data processing (DP) device coupled to the home network 102 is usually associated with the home network 102, but has moved to the new area network 103, for example. When sending a data packet to a data processing device,
The data packet is transmitted by the first DP device to the mobility support router (MS) which is located closest to the first DP device.
R) 106a. The MSR 106a initiates a local search to determine if the MH data processor is currently bound to the home network 102, and if determined to be bound, the MSR 106a routes the data packet to the home network 102. To the MH data processing device. On the other hand, if it is determined that the MH data processing device is not connected to the home network, M
The SBR 105a seeks the network in which the MH data processing device was located at the earliest, and searches the tunnel route table describing the position information of the MH data processing device.

Next, the MSBR 105a is replaced by the MSR 106a.
"OTHER HA" request to "WHO HAS"
The current position of the MH data processing device is sent to the MS
Notify R106a. Therefore, the MSR 106a is
The H data processing device tunnels the data packet to the MSBR 105b belonging to the currently connected new area network, and the MSBR 105b tunnels the data packet to the MSR 106c. The MSR 106c of the new area network 103 then sends the data packet to the MH data processor. The movement of the MH data processing device inside the new area network 103 is the MSB of the new area network 103.
The message transmitted from the DP device of the new area network 103 to the MH data processing device as detected by R105b is simply the new area network 1
Routing is optimized because it need not be sent to the 03 closest MSR 106c and sent to the MSBR 105a of the home network 102.

When a DP device connected to another area network 104 desires to send a data packet to the MH data processing device, the DP device coupled to the other area network 104 first sends the data packet. The data is transmitted to the MSBR 105a connected to the home network 102 of the MH data processing device. The MSBR 105a of the home network 102 searches the tunnel route table and determines that the MH data processing device is located in the new area network 103. Therefore, the data packet is transmitted to the new area network 10
3 MSBR105b is tunneled to the MSB
The R105b sends the data packet to the MH data processing device, so
Tunnel to R106c. Home network 1
No. 02 MSBR 105a is another area network 10
4 to the MSBR 105c, a redirection message for retransmitting the data packet is transmitted, so that all subsequent data packets transmitted between the DP device and the MH data processing device of the different area network are transmitted to the different area network. Direct tunneling from the MSBR 105c at 104 to the MSBR 105b at the new area network 103, thereby again optimizing routing.

For example, the MH data processing device is changed from the new area network 103 to another area network 10
4 to the local MSR 106 in another area network 104 to which the MH data processor is currently connected.
b notifies the home network 102 and the MSBRs 105a and 105b of the new area network 103 to which the MH data processing device was previously connected that the MH data processing device is currently connected to another area network 104. By this notification, the MSBRs 105a to 105c of the home network 102, the new area network 103, and the different area network 104
Since the tunnel route table of the above is updated, any data packet destined to the MH data processing device is directly transmitted to the MSBR 105c of the another area network 104. When the MH data processing device further moves to the different area network 104 again, the MH data processing device notifies the new local MSR 106c of the MSR to which the MH data processing device was previously connected. Then, the MSR 106c determines the MSBR 105 of the previous area in which the MH was included and the current area and home area.
Notify a to 105c. This allows the MSBR105
a-105c can update its tunnel route table.

[0009]

In the system according to the conventional example, the MH data processing device can be moved between networks, and data packets can be transmitted / received across networks. Therefore, the OSPF backbone network 101 is provided for each network. In addition, since a mobility support boundary router (MSBR) for connecting the network is required, there is a problem that the network configuration becomes complicated.

In order to manage the position of the MH data processor in the home network 102, the MSBR 105a of the home network 102 and the MSs of other networks are managed.
Between the BR and the MSBR1 of the home network 102
"WHO HAS" between 05a and MSR106a
There is a problem that it is necessary to send and receive special messages such as "I HAVE" and "OTHER HAS".

Further, in the above system, the MSB of the home network is first transmitted for the purpose of transmitting / receiving the data packet directly between the MSBR of the transmission source and the MSBR of the transmission destination without passing through the MSBR of the home network.
A data packet is sent to R, and a redirection message is sent from that MSBR to the source MSBR of the data packet. Therefore, there is a problem in that the data packet transmission procedure becomes complicated.

The present invention has been made in view of the above problems, and an object thereof is a packet routing device capable of realizing data transmission / reception to / from a mobile terminal moving between a plurality of sub-networks with a simple structure. To provide.

[0013]

In order to solve the above-mentioned problems, a packet routing device according to the first invention is connected to a plurality of sub-networks and performs a packet routing between the plurality of sub-networks by one unit. A packet routing device, comprising a plurality of network interface cards each connected to one of the plurality of sub-networks, and a terminal connected to each of the plurality of network interface cards and communicatively connected to a corresponding sub-network. A plurality of sub-network relay means for respectively relaying IP packets transmitted and received by the sub-network relay means, and an IP packet connected to the plurality of sub-network relay means and received from the sub-network relay means based on the header information of the other sub-network. Luci as a relay IP packet routing means for routing the IP packet to the mobile terminal whose home network is a sub-network connected to the sub-network relay means via the network interface card. When it is received from the IP packet routing means, it is connected to the means for returning to the IP packet routing means so as to transfer it to the movement destination sub-network of the mobile terminal, the sub-network relay means and the network interface card. And a means for relaying, to a mobile terminal, an IP packet transferred to the mobile terminal when the mobile terminal having another subnetwork as a home network is communicatively connected to the subnetwork.

A packet routing device according to a second aspect of the present invention is the packet routing device according to the first aspect of the present invention, wherein the sub-network relay means is connected to the sub-network relay means via the network interface card. An IP address including information specifying a network is assigned.

A packet routing device according to a third aspect of the present invention is the packet routing device according to the first or second aspect of the present invention, wherein the sub-network relay means has at least some of the functions of both the foreign agent and the home agent. It is provided in the same module.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1. FIG. 1 is a block diagram of a packet routing device according to the present invention. In the figure, 1
Shows the present packet routing device. 2 is an IP (Internet Protocol) provided in the packet routing device 1.
l) A routing unit, which has a function equivalent to that of an existing IP router, routes an IP packet to a corresponding sub-network according to an IP address included in its header information.

Reference numerals 3a and 3b denote IP encapsulation / decapsulation units, and internal memory (not shown) that stores the position information (such as the network address of the destination subnetwork) of the mobile terminal whose home network is the corresponding subnetwork 5a to 5c. Stored in the IP routing unit 2
The IP packet addressed to the mobile terminal received by is encapsulated with the address of the destination network and sent out to the network again. Furthermore, when a mobile terminal whose home network is another network moves to any of the sub-networks 5a to 5c, the IP encapsulation / decapsulation unit 3 encapsulates the IP packet addressed to the mobile terminal. Is transferred, the IP packet is decapsulated and I / O of the lower layer is decapsulated.
It is sent to the network via the F card 4. This I
The P encapsulation / decapsulation units 3a to 3c are HAs described later.
The position management unit 8 and the FA position management unit 9 constitute a sub-network relay unit.

Reference numerals 4a to 4c are I / F cards (network interface cards) that connect the IP encapsulation / decapsulation units 3a to 3b and their corresponding sub-networks 5a to 5b. When the mobile terminal managed by the corresponding IP encapsulation / decapsulation unit 3 is moving to another network, this I / F card 4 sends the IP packet addressed to the mobile terminal to the corresponding subnetwork 5a ... 5c, and sends it to the IP encapsulation / decapsulation units 3a to 3c. The packet routing device 1 has three or more I / Fs.
A slot (not shown) capable of storing a card is provided, and the I / F cards 4a to 4c are stored in this slot.

A subnetwork 5 is managed by each IP encapsulation / decapsulation unit 3. Reference numeral 6 denotes a mobile terminal which uses the sub-network 5a as a home network and can move and communicate with the sub-networks 5a to 5c so that IP packets can be transmitted and received even at the destination. Further, 7a is a fixed terminal connected to the sub-network 5a, and 7b is a fixed terminal connected to the sub-network 5c.

Reference numeral 8 denotes an HA location management section having a location management function of a home agent (HA) which performs location management of a mobile terminal having each IP encapsulation / decapsulation section 3 as a home network. On the other hand, 9 is an FA location management unit having a location management function of a foreign agent (FA) that manages an IP address at the destination when each mobile terminal moves to a subnetwork 5a to 5c other than the home network. Home agents and foreign agents are IETF (Internet Engineering Tas
k Force) RFC2002 “IP Mobility Support”.

FIG. 2 shows a case where the fixed terminal 7a in the subnetwork 5a sends an IP packet to the mobile terminal 6 when the mobile terminal 6 moves from its home network, the subnetwork 5a, to the subnetwork 5b. 5 is a diagram for explaining routing of the IP packet in FIG.

As shown in the figure, the sub-network 5a
When the fixed terminal 7a in the mobile terminal 6 transmits an IP packet addressed to the mobile terminal 6, the IP encapsulation / decapsulation unit 3a recognizes that the mobile terminal 6 is moving to the subnetwork 5b. The IP by the card 4a
The packet is taken in, encapsulated with the address of the destination IP encapsulation / decapsulation unit 3 based on the position information of the mobile terminal 6, and transferred to the IP routing unit 2. The IP routing unit 2 refers to the destination address of the encapsulated IP packet and transfers the IP packet to the IP encapsulation / decapsulation unit 3b. IP
The encapsulation / decapsulation unit 3b decapsulates the received IP packet and transfers it from the I / F card 4b to the subnetwork 5b. Thus, the IP packet can be transferred to the mobile terminal 6 in the subnetwork 5b.

Embodiment 2. FIG. 3 shows a case where the fixed terminal 7b in the subnetwork 5c transmits an IP packet addressed to the mobile terminal 6 when the mobile terminal 6 moves from its home network, the subnetwork 5a, to the subnetwork 5b. It is a figure explaining the routing of an IP packet.

As shown in the figure, since the destination address of the IP packet transmitted from the fixed terminal 7b is the subnetwork 5a, the IP encapsulation / decapsulation unit 3
The c acquires the IP packet from the I / F card 4c and transfers it to the IP routing unit 2. In the IP routing unit 2, since the destination address of the received IP packet belongs to the subnetwork 5a in the lower layer of the IP encapsulation / decapsulation unit 3a, the IP packet is sent to the IP encapsulation / decapsulation unit 3a. Forward.
The IP encapsulation / decapsulation unit 3a receives the received IP
From the destination address of the packet, it is identified that the IP packet is addressed to the mobile terminal 6. And
The IP encapsulation / decapsulation unit 3a uses the location management information of the mobile terminal 6 to determine that the mobile terminal 6 is a subnetwork 5 of a lower layer of the IP encapsulation / decapsulation unit 3b.
Since it is recognized that the IP packet is connected to b, the received IP packet is encapsulated with the address of the IP encapsulation / decapsulation unit 3b and transferred to the IP routing unit 2. The IP routing unit 2 transfers the IP packet from the destination address of the encapsulated IP packet to the IP encapsulation / decapsulation unit 3b. The IP encapsulation / decapsulation unit 3b decapsulates the received encapsulated IP packet and transfers the IP packet from the I / F card 4b to the subnetwork 5b. Thus, the IP packet can be transferred to the mobile terminal 6 in the subnetwork 5b.

As described in the first and second embodiments above, in the packet routing device 1, the plurality of I / F cards 4a to 4c and the IP encapsulation / decapsulation unit 3 are used.
a to 3c are attached and communication relay with the sub-networks 5a to 5c is performed by them. As a result, the IP routing unit 2 is shared, and the location management and encapsulation / decapsulation processing of each mobile terminal are independently performed in units of sub-networks. Using the unit 2 as it is, it is possible to easily add a subnetwork corresponding to the mobile terminal. Thus, even when a mobile terminal moves between a plurality of sub-networks by one packet routing device, proper packet transfer can be performed.

Embodiment 3. FIG. 4 is a sequence diagram illustrating the operation of the packet routing device 1 when the mobile terminal 6 having the subnetwork 5a as the home network moves from the subnetwork 5b to the subnetwork 5c.

As shown in the figure, first, when the mobile terminal 6 moves from the subnetwork 5b to the subnetwork 5c, the IP encapsulation / decapsulation unit 3c announces the network IP address of the subnetwork 5c ( S20), when the mobile terminal 6 receives this network IP address, the mobile terminal 6 determines that the mobile terminal 6 has moved from the sub-network 5b to the sub-network 5c, and the IP encapsulation / decapsulation unit 3c makes a provisional provision in the sub-network 5c. I to request another IP address
A P packet (position registration request) is transmitted (S21).

Upon receipt of this IP packet, the IP encapsulation / decapsulation unit 3c instructs the FA position management unit 9 to communicate with the IP encapsulation / decapsulation unit 3a which is in charge of managing the mobile terminal 6. A request is made to allocate a temporary IP address to be used for transferring the IP packet to S6 (S22). Next, the FA location management unit 9 notifies the IP encapsulation / decapsulation unit 3c of the temporary IP address assigned to the mobile terminal 6 (S23),
The HA position management unit 8 is also notified of the newly assigned temporary IP address (S24). Upon receipt of this IP address, the HA location management unit 8 sends to the IP encapsulation / decapsulation unit 3a the I destination that is the transfer destination of the IP packet addressed to the mobile terminal 6.
The mobile terminal 6 is notified of the P address (S25).
Is a temporary I registered in the IP encapsulation / decapsulation unit 3b that manages the sub-network 5b before moving.
A request is made to delete the P address (S26).

Further, the IP encapsulation / decapsulation unit 3
a newly registers the provisional IP address assigned to the mobile terminal in the destination subnetwork 5c as the location information of the mobile terminal 6, and the IP address assigned in the subnetwork 5b that has been registered until then. When it is deleted, a response indicating that the registration / deletion process has been completed
It returns to the A position management unit 8 (S27). Further, the IP encapsulation / decapsulation unit 3b deletes the position information regarding the mobile terminal 6 and returns a response to the HA position management unit 8 (S28).
Then, the HA position management unit 8, the FA position management unit 9, and I
The P encapsulation / decapsulation unit 3c notifies each of the completion of registration (S29, S30, S31).

By allocating one IP address to each IP encapsulation / decapsulation unit 3 in this way,
Notification of registration or deletion of position information associated with the movement of the mobile terminal 6 managed by each IP encapsulation / decapsulation unit 3 is sent between the HA position management unit 8 and the FA position management unit 9 in one device. This can be done using IP packets.

Fourth Embodiment FIG. 5 is a functional block diagram showing a packet routing device according to the fourth embodiment. This packet routing device 1a shown in the figure is an HA in the packet routing device 1 already shown in FIG.
It is configured to include agent / IP encapsulation units 10a to 10c in which the functions of the position management unit 8 and the FA position management unit 9 are included in the IP encapsulation / decapsulation units 3a to 3c, respectively. For other configurations, see FIG.
Since it is the same as the packet routing device 1 already shown in FIG.

In FIG. 6, the mobile terminal 6 whose home network is the sub-network 5a is the sub-network 5b.
FIG. 9 is a sequence diagram illustrating an operation of the packet routing device 1a when moving from the sub network 5c to the sub network 5c.

As shown in the figure, first, when the mobile terminal 6 moves from the subnetwork 5b to the subnetwork 5c, the agent / IP encapsulation / decapsulation unit 10c informs the network IP address of the subnetwork 5c. Cage (S40), this network I
When the mobile terminal 6 receives the P address, the mobile terminal 6 itself moves from the sub-network 5b to the sub-network 5c.
Agent / IP encapsulation /
An IP packet (location registration request) requesting a temporary IP address in the subnetwork 5c is transmitted to the decapsulation unit 10c (S41). Agent / IP encapsulation / decapsulation unit 10 that receives this IP packet
The c allocates an IP address for transferring the IP packet to the mobile terminal 6 to the agent / IP encapsulation / decapsulation unit 10a, and notifies the agent / IP encapsulation / decapsulation unit 10a of the IP address (S42). ).

The agent / IP encapsulation / decapsulation unit 10a manages the sub-network 5b that the mobile terminal 6 was in before the movement.
The decapsulation unit 10b is requested to delete the registered temporary IP address (S43). Then, the agent / IP encapsulation / decapsulation unit 10b
The P-address is deleted, and the agent
Responds to the IP encapsulation / decapsulation unit 10a (S
44).

Further, the agent / IP encapsulation / decapsulation unit 10a uses the destination subnetwork 5c.
When the IP address assigned in step 2 is registered as the location information of the mobile terminal 6 and the IP address assigned in the sub-network 5b that has been registered up to that point is deleted, a response indicating that the registration / deletion process has been completed is sent to the agent. -Return to the IP encapsulation / decapsulation unit 10c (S45). And the agent that received this response
The IP encapsulation / decapsulation unit 10c returns to the mobile terminal 6 that the location registration request has been accepted (S46).

The packet routing device according to the present embodiment is different from the packet routing device according to the above-mentioned third embodiment in that the HA position management unit 8 and the FA position management unit 9 and the agent / IP encapsulation / Since the transmission and reception of the position information with the decapsulation unit 10 is eliminated, the processing can be simplified.

[0038]

As described above, according to the packet routing device of the first aspect, a plurality of sub-networks are connected through a plurality of network interface cards, and the sub-network relaying means performs IP in sub-network units. Since the packet is relayed by communication, it is possible to easily add or delete the subnetwork to be managed. Further, since one packet routing device manages a plurality of sub-networks, the network configuration can be simplified.

According to the packet routing device of the second aspect, since the IP address is assigned to the sub-network relaying means, the communication between each sub-network relaying means and the IP routing means is performed by using the IP packet. be able to. Further, according to this configuration, by encapsulating / decapsulating with a predetermined IP header, the IP packet can be easily transferred between the sub-network relay units.

According to the packet routing device of the third aspect, since at least a part of the functions of the home agent and the foreign agent are included in the sub-network relay means as the same module, the communication amount in the packet routing device is reduced. The amount can be reduced.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a packet routing device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an IP packet transfer route in a packet routing device according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of an IP packet transfer route in a packet routing device according to an embodiment of the present invention.

FIG. 4 is a diagram showing a position registration sequence of a mobile terminal in the packet routing device according to the embodiment of the present invention.

FIG. 5 is a functional block diagram of a packet routing device according to another embodiment of the present invention.

FIG. 6 is a diagram showing a position registration sequence of a mobile terminal in a packet routing device according to another embodiment of the present invention.

FIG. 7 is a diagram showing a configuration of a communication system according to a conventional example.

[Explanation of symbols]

1, 1a packet routing device, 2 IP routing unit, 3a to 3c IP encapsulation / decapsulation unit,
4a-4c I / F card (network interface card), 5a-5c sub-network, 6 mobile terminals, 7a, 7b fixed terminal, 8 HA position management unit, 9
FA location management unit, 10a to 10c Agent I
P encapsulation / decapsulation unit.

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-4-319837 (JP, A) JP-A-5-83260 (JP, A) JP-A-8-56263 (JP, A) JP-A-6- 337824 (JP, A) JP-A-6-149689 (JP, A) JP-A-9-214516 (JP, A) JP-A-7-129488 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/56 H04B 7/26

Claims (3)

(57) [Claims] 1. A packet routing device that is connected to a plurality of sub-networks and performs packet routing between the plurality of sub-networks by one unit, and a plurality of packet routing devices that are respectively connected to any of the plurality of sub-networks. A network interface card, a plurality of sub-network relay units that are respectively connected to the plurality of network interface cards and relay IP packets transmitted and received by terminals that are communicatively connected to a corresponding sub-network, and the plurality of sub-network relays IP packet routing means connected to the sub-network relay means for routing the IP packet received from the sub-network relay means to another sub-network relay means based on the header information of the sub-network relay means. When an IP packet addressed to a mobile terminal whose home network is a sub-network connected to the sub-network relay means via the network interface card is received from the IP packet routing means, the IP packet is transferred to the destination sub-network of the mobile terminal. Means for returning to the IP packet routing means for transferring the data, and a mobile terminal having another subnetwork as a home network is communicatively connected to the subnetwork connected to the subnetwork relay means through the network interface card. And a means for relaying an IP packet transferred to the mobile terminal to the mobile terminal when the packet routing apparatus is present. 2. An IP address including information for identifying a sub-network connected to the sub-network relaying means via the network interface card is assigned to the sub-network relaying means. The described packet routing device. 3. The packet routing device according to claim 1, wherein the sub-network relay unit includes at least a part of both functions of a foreign agent and a home agent in the same module.