WO2021229658A1 - Packet transfer system and packet transfer method - Google Patents

Abstract

A packet transfer system, according to the present invention, comprising: a transfer control device that controls packet transfer; a transfer device that transfers packets on the basis of a transfer rule defined by the transfer control device; and a communication device newly connected to the transfer device, wherein the communication device sends a control packet to the transfer device, the transfer device adds, to the control packet sent from the communication device, physical port identifying information that specifies a physical port which has received the control packet, and identifying information for the transfer device itself, and transfers the control packet to the transfer control device, and the transfer control device acquires the transfer device identifying information and physical port identifying information added to the control packet.

Description

Packet transfer system and packet transfer method

The present invention relates to a packet transfer system and a packet transfer method.

The outline of the technique disclosed in Non-Patent Document 1 will be described with reference to FIG. FIG. 9 is a block diagram showing a communication network system 100 in which the OpenFlow protocol operates. The communication network system 100 includes an OpenFlow controller 101, OpenFlow switches 110, 111, 112, and a DHCP (Dynamic Host Configuration Protocol) server 120.

The OpenFlow switches 110 and 111 are connected, and each of them has established a connection with the OpenFlow controller 101 in advance. The OpenFlow switch 111 is connected to the DHCP server 120. In this state, it is assumed that the OpenFlow switch 112 is newly connected to the OpenFlow switch 110.

When the OpenFlow switch 112 is connected to the OpenFlow switch 110, it is connected to the OpenFlow switch 110 by using the data transfer port instead of the management port. In the OpenFlow switch 112, the DHCP client is operating, and the OpenFlow switch 112 is recognized by the OpenFlow controller 101 by the following procedure.

(1) The OpenFlow switch 112 transmits a DHCP message to the OpenFlow switch 110. The OpenFlow switches 110 and 111 transfer the DHCP message transmitted by the OpenFlow switch 112 to the DHCP server 120.

(2) The DHCP server 120 transmits the IP (Internet Protocol) address and port number of the OpenFlow controller 101 to the OpenFlow switch 112. The OpenFlow switches 110 and 111 transfer the IP address and port number of the OpenFlow controller 101 transmitted by the DHCP server 120 to the OpenFlow switch 112.

(3) The OpenFlow agent operating in the OpenFlow switch 112 takes in the IP address and port number of the OpenFlow controller 101. The OpenFlow agent connects to the OpenFlow controller 101 based on the captured IP address and port number. The OpenFlow controller 101 detects the connection relationship between the OpenFlow switches 110, 111, 112 by using LLDP (Link Layer Discovery Protocol) or the like.

In this way, the newly connected OpenFlow switch 112 establishes a connection with the OpenFlow controller 101 by superimposing it on the data network without using the management port and network. The OpenFlow controller 101 can detect the connection relationship between the OpenFlow switches 110, 111, 112. Therefore, it is possible to reduce the cost required for the installation and management of management ports and networks.

In the technique disclosed in Non-Patent Document 1, it is necessary that the DHCP client and the OpenFlow agent are operating in the newly connected OpenFlow switch 112. Further, in the technique disclosed in Non-Patent Document 1, it is premised that the OpenFlow switch 112 is provided with a CPU (Central Processing Unit) or the like for operating them.

Here, it is assumed that the device connected to the OpenFlow switch 110 is a modular communication device. Such modular communication devices may not have a port dedicated to management. Further, in terms of size and cost, it may not be equipped with an OpenFlow agent, a CPU for operating a DHCP client, or the like. Therefore, in such a modular communication device, it may not be possible to connect to the OpenFlow controller 101.

In view of the above circumstances, an object of the present invention is to provide a technique capable of connecting to a controller by a simple method even if it is a communication device that cannot operate an OpenFlow agent, a DHCP client, or the like.

One aspect of the present invention is a transfer control device that controls the transfer of a packet, a transfer device that transfers the packet based on a transfer rule defined by the transfer control device, and a communication device newly connected to the transfer device. A packet forwarding system comprising: The communication device sends a control packet to the forwarding device, and the forwarding device receives the control packet for the control packet sent from the communication device. The physical port identification information that identifies the physical port and the identification information of the own device are added and transferred to the transfer control device, and the transfer control device uses the identification information of the transfer device assigned to the control packet. And a packet forwarding system that acquires the physical port identification information.

One aspect of the present invention is a transfer control device that controls the transfer of a packet, a transfer device that transfers the packet based on a transfer rule defined by the transfer control device, and a communication device newly connected to the transfer device. A packet forwarding method in a packet forwarding system comprising the above, wherein the communication device sends a control packet to the forwarding device, and the forwarding device controls the control packet sent from the communication device. The physical port identification information that identifies the physical port that received the packet and the identification information of the own device are added and transferred to the transfer control device, and the transfer control device transfers the transfer attached to the control packet. This is a packet forwarding method for acquiring device identification information and the physical port identification information.

According to the present invention, even a communication device that cannot operate an OpenFlow agent, a DHCP client, or the like can be connected to a controller by a simple method.

It is a block diagram which shows the structure of the packet transfer system in 1st Embodiment. It is a block diagram which shows the structure of the packet transfer system which is a specific example of 1st Embodiment. It is a sequence diagram which shows the flow of the connection configuration collection processing by the packet transfer system in 1st Embodiment. It is a figure which shows the information of the connection structure recorded by the transfer control apparatus in 1st Embodiment. It is a block diagram which shows the structure of the packet transfer system in 2nd Embodiment. It is a sequence diagram which shows the flow of a part of the connection configuration collection processing by a packet transfer system in 2nd Embodiment. It is a block diagram which shows the structure of the packet transfer system in 3rd Embodiment. It is a sequence diagram which shows the flow of a part of the connection configuration collection processing by a packet transfer system in 3rd Embodiment. It is a figure for demonstrating the technique disclosed in Non-Patent Document 1.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Overview)
First, the outline of the packet transfer system of the present invention will be described.
In the packet transfer system of the present invention, one or more transfer devices are connected to the transfer control device. One or a plurality of transfer devices have a plurality of ports, and a spanning tree-shaped logic path rooted at the transfer control device is preset in the plurality of ports. The spanning tree-shaped logical path may be set by the transfer control device in each transfer device, or may be set in each transfer device according to an instruction from the transfer control device.

When a communication device is newly connected to any of the transfer devices, the communication device transmits a control packet to the transfer control device through the logical path. The communication device transmits a control packet at regular intervals from the time when the power is turned on and started, or transmits a control packet in response to an instruction from the outside (for example, a transfer control device). Since the logical path is configured in a spanning tree shape, loops of control packets and the like do not occur. The control packet always reaches the transfer control device through the port of the transfer device corresponding to the root.

The transfer device to which the communication device is connected receives the control packet through the logical path. The transfer device to which the communication device is connected attaches the identification information of the physical port that received the control packet and the identification information of the transfer device (own device) to the control packet, and transfers the control packet to the transfer control device.

The transfer control device identifies the newly connected communication device based on the information given to the control packet transferred from the transfer device, and also identifies the transfer device newly connected to the communication device and its physical port. .. By setting the spanning tree-shaped logical path for one or a plurality of transfer devices in this way, the transfer device to which the communication device is newly connected and the physical port thereof can be specified. As a result, the newly connected communication device can be connected to the transfer control device. Therefore, even a communication device that cannot operate an OpenFlow agent, a DHCP client, or the like can be connected to the controller by a simple method.
Hereinafter, embodiments that configure the above packet transfer system will be described.

(First Embodiment)
FIG. 1 is a block diagram showing a configuration of a packet transfer system 1 according to the first embodiment. The packet transfer system 1 includes a transfer control device 2, an OpenFlow switch 3, an autonomous transfer device 4, and a communication device 5.

The transfer control device 2 controls the packet route. The transfer control device 2 transmits information indicating a transfer rule defined in the transfer control device 2 (hereinafter referred to as “transfer rule information”) to the OpenFlow switch 3. The transfer control device 2 is, for example, a controller in SDN (Software Designed Network). In the following description, it is assumed that the transfer control device 2 is an OpenFlow controller.

The transfer rule information is, for example, an OpenFlow flow entry. The forwarding rule information includes information for identifying a packet to be forwarded and information indicating processing for the identified packet. The processing for the specified packet is, for example, a processing for transferring the packet to a specific route, a processing for rewriting or deleting a part of the data of the packet, a processing for discarding the packet, and the like.

The transfer control device 2 receives the Packet-In message of the OpenFlow protocol transmitted by the OpenFlow switch 3. The transfer control device 2 transmits a Packet-Out message of the OpenFlow protocol to the OpenFlow switch 3. The transfer control device 2 instructs the OpenFlow switch 3 and the autonomous transfer device 4 to set a logical path. The transfer control device 2 may set a logical path for the OpenFlow switch 3 and the autonomous transfer device 4.

The OpenFlow switch 3 includes an autonomous transfer device transmission / reception unit 31, a search logic path generation unit 32, a transfer rule storage unit 34, a transfer processing unit 35, a transfer control device transmission / reception unit 36, and an external transmission / reception unit 37.

The transfer control device transmission / reception unit 36 is a physical port connected to the transfer control device 2. The transfer control device transmission / reception unit 36 connects to the transfer control device 2 via the physical line 7. The transfer control device transmission / reception unit 36 establishes a secure channel connection with the transfer control device 2 and transmits / receives data according to the OpenFlow protocol.
The external transmission / reception unit 37 is a port to which another OpenFlow switch, a communication network such as the Internet, or the like is connected to the OpenFlow switch 3. The communication device 5 may be directly connected to the external transmission / reception unit 37. The external transmitter / receiver 37 may be a single or a plurality of physical ports.

The autonomous transfer device transmission / reception unit 31 is a physical port connected to the autonomous transfer device 4. FIG. 1 shows an example in which the autonomous transfer device transmission / reception unit 31 is connected to the autonomous transfer device 4 via a physical line 6-n. When the OpenFlow switch 3 is connected to a plurality of autonomous transfer devices 4, the OpenFlow switch 3 includes an autonomous transfer device transmission / reception unit 31 corresponding to each of the plurality of autonomous transfer devices 4.

The autonomous transfer device transmission / reception unit 31, transfer control device transmission / reception unit 36, and external transmission / reception unit 37 have different names for convenience of explanation, but they are all physical ports included in the OpenFlow switch 3. The physical port connected to the transfer control device 2 becomes the transfer control device transmission / reception unit 36, the physical port connected to the autonomous transfer device 4 becomes the autonomous transfer device transmission / reception unit 31, and the other physical ports are the external transmission / reception unit 37. become.

The transfer rule storage unit 34 stores the transfer rule information transmitted by the transfer control device 2 to the OpenFlow switch 3. The forwarding rule information is written in the forwarding rule storage unit 34 as follows. The transfer control device transmission / reception unit 36 receives transfer rule information from the transfer control device 2. The transfer control device transmission / reception unit 36 outputs the received transfer rule information to the transfer processing unit 35. The transfer processing unit 35 writes the transfer rule information output by the transfer control device transmission / reception unit 36 to the transfer rule storage unit 34.

The search logical path generation unit 32 generates a logical path composed of spanning trees having the transfer processing unit 35 as a node in response to an instruction from the transfer control device 2. The spanning tree has a physical link between the transfer devices (for example, between the OpenFlow switch 3 and the autonomous transfer device 4) as a branch, and the transfer processing unit of the transfer device directly connected to the transfer control device as a root. However, it is configured so that loops do not occur. Here, for example, the tag VLAN (Virtual Local Area Network) is applied to the generation of the logical path. The search logical path generation unit 32 associates a VLAN-ID (Identifier) indicating the generated logical path with identification information (hereinafter referred to as “physical port identification information”) that identifies the autonomous transfer device transmission / reception unit 31. Add to the transfer rule information stored in the transfer rule storage unit 34. The forwarding rule information may be preset with a rule for Packet-In the control packet. For example, when a control packet is received, a rule for forwarding a Packet-In message to the forwarding control device 2 may be set in advance in the forwarding rule information.

The transfer processing unit 35 selects a process for the received packet based on the transfer rule information stored in the transfer rule storage unit 34, and performs the selected process on the packet.

The autonomous transfer device 4 is, for example, a device corresponding to a Layer 2 switch. The autonomous transfer device 4 includes physical ports 41-1 to 41-N, an autonomous search logic path generation unit 42, an autonomous transfer processing unit 44, and an autonomous transfer rule storage unit 45. Physical lines 6-1 to 6-N are connected to each of the physical ports 41-1 to 41-N. Note that N is an integer of 2 or more, and n is an arbitrary integer of 1 to N. In FIG. 1, the physical line 6-n is assumed to indicate any one of the physical lines 6-1 to 6-N.

The autonomous transfer rule storage unit 45 stores predetermined autonomous transfer rule information. The autonomous transfer rule information is information indicating the rules of the transfer process performed by a general Layer2 switch. For example, the autonomous forwarding rule information includes information for identifying a packet to be forwarded and information indicating processing for the identified packet. The process for the specified packet is, for example, a process of transferring the packet to the physical ports 41-1 to 41-N to which the device having the destination MAC (Media Access Control) address is connected. For example, it is assumed that the following information is also registered in the autonomous forwarding rule information. In the spanning tree logical path, packets received on a physical port connected to a node far from the root of the spanning tree (ie, children in the tree structure) and packets received on the physical port corresponding to the leaves of the spanning tree are nodes near the root (ie, tree). Sent to the physical port connected to the parent) in the structure.

The autonomous search logic path generation unit 42 permits the communication device 5 to connect to the physical ports 41-1 to 41-N with the OpenFlow switch 3 as the root in response to the instruction of the transfer control device 2. That is, the autonomous search logic path generation unit 42 generates a logic path constituting a spanning tree having physical ports 41-1 to 41-N to which the communication device 5 may be connected as leaves.

The autonomous search logical path generation unit 42 assigns the same VLAN-ID as the VLAN-ID assigned to the logical path by the search logical path generation unit 32 of the OpenFlow switch 3 to the generated logical path. .. The logic path generation unit 42 for autonomous search includes identification information (hereinafter referred to as “physical port identification information”) that identifies physical ports 41-1 to 41-N to which VLAN-ID is assigned, and the assigned VLAN-ID. Is associated with and written in the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45.

The autonomous transfer processing unit 44 selects a process for the received packet based on the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45, and performs the selected process on the packet. When the control packet transmitted by the communication device 5 is captured, the autonomous transfer processing unit 44 performs the following processing. Specifically, when the captured control packet is not given the assigned information regarding the other autonomous transfer device 4, the autonomous transfer processing unit 44 stores the identification information of its own device in the internal storage area in advance. And the assigned information including the physical port identification information that received the control packet is attached to the control packet, and then the control packet is forwarded.

The communication device 5 is, for example, a modular communication device having an IP communication function. Here, the modular communication device is a communication device having limited functions, for example, which does not have a port dedicated to management and does not have a CPU on which an OpenFlow agent or a DHCP client operates. In FIG. 1, for convenience of explanation, the communication device 5 is connected to the physical port 41-1 of the autonomous transfer device 4 via the physical line 6-1. Such a modular communication device is not available. There is also a form in which the physical port 41-1 is connected as it is without using the physical line 6-1.

When the power is turned on and started, the communication device 5 sends out a control packet containing the identification information of the own device at regular intervals. The identification information of the own device is, for example, information such as a MAC address and an IP address.

FIG. 2 is a block diagram showing a configuration of a packet transfer system 1a which is a specific example of the first embodiment. In FIG. 2, the same components as those in FIG. 1 are designated by the same reference numerals. The packet transfer system 1a includes a transfer control device 2, an OpenFlow switch 3, autonomous transfer devices 4a and 4b, and communication devices 5a and 5b. In the following description, when each of the internal functional parts of the autonomous transfer devices 4a and 4b is shown, "a" and "b" are added to the reference numerals of the respective functional parts.

The autonomous transfer device 4a includes four physical ports 41a-1, 41a-2, 41a-3. The autonomous transfer device 4b includes four physical ports 41b-1, 41b-2, 41b-3.

The physical port 41a-1 of the autonomous transfer device 4a and the autonomous transfer device transmission / reception unit 31 of the OpenFlow switch 3 are connected by a physical line 6a-1. The physical port 41a-3 of the autonomous transfer device 4a and the physical port 41b-1 of the autonomous transfer device 4b are connected by a physical line 6a-3. The communication device 5a is connected to the physical port 41b-2 of the autonomous transfer device 4b via the physical line 6b-2, and communicates with the physical port 41a-2 of the autonomous transfer device 4a via the physical line 6a-2. The device 5b is connected.

The search logic path generation unit 32 of the OpenFlow switch 3, the autonomous search logic path generation unit 42a of the autonomous transfer device 4a, and the autonomous search logic path generation unit 42a of the autonomous transfer device 4b are transfer control devices. The logic path 60 shown in FIG. 2 is generated according to the instruction of 2.

The search logic path generation unit 32 assigns any one free VLAN-ID to the autonomous transfer device transmission / reception unit 31. Here, for example, it is assumed that "1001" is assigned as the VLAN-ID. The search logic path generation unit 32 transmits the assigned VLAN-ID “1001” to the autonomous search logic path generation units 42a and 42b. The search logical path generation unit 32 writes the transfer rule information stored in the transfer rule storage unit 34 in association with the physical port identification information of the autonomous transfer device transmission / reception unit 31 and the VLAN-ID “1001”.

The autonomous search logic path generation units 42a and 42b receive the information of the VLAN-ID "1001" transmitted by the search logic path generation unit 32. The autonomous search logic path generation unit 42a has the physical port identification information corresponding to each of the physical ports 41a-1, 41a-2, 41a-3 and the VLAN-ID "1001" received from the search logic path generation unit 32. Is written in the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45a in association with. Similarly, the autonomous search logical path generation unit 42b also has the physical port identification information corresponding to each of the physical ports 41b-1, 41b-2, and 41b-3, and the VLAN-ID received from the search logical path generation unit 32. It is written in the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45b in association with "1001". As a result, the logical path 60 corresponding to the VLAN-ID "1001" is generated.

(Connection configuration collection process by the packet transfer system in the first embodiment)
FIG. 3 is a sequence diagram showing a flow of processing for collecting the connection configuration of the communication device 5a by the packet transfer system 1a shown in FIG. It is assumed that the communication device 5a is started in a state of being connected to the physical port 41b-2 of the autonomous transfer device 4b. The communication device 5a sends a control packet including the identification information of the own device to the physical line 6b-2 at regular intervals (step Sa1).

The physical port 41b-2 of the autonomous transfer device 4b receives the control packet transmitted by the communication device 5a. The physical port 41b-2 outputs the received control packet to the autonomous transfer processing unit 44b (step Sa2). The autonomous transfer processing unit 44b captures the control packet output by the physical port 41b-2. No grant information is given to the captured control packet. Therefore, the autonomous transfer processing unit 44b reads out the identification information of the autonomous transfer device 4b from the internal storage area. The autonomous transfer processing unit 44b generates grant information including the read identification information of the autonomous transfer device 4b and the physical port identification information of the physical port 41b-2 that has captured the control packet. The autonomous transfer processing unit 44b adds the generated grant information to the control packet (step Sa3).

The autonomous transfer processing unit 44b refers to the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45b, and refers to the control packet via the logical path 60 associated with the physical port 41b-2 that has captured the control packet. Is transferred (step Sa4). Specifically, the transfer is performed as follows. In the autonomous forwarding rule information stored in the autonomous forwarding rule storage unit 45b, the VLAN-ID "1001" is associated with the physical port 41b-2 that has captured the control packet. The autonomous transfer processing unit 44b refers to the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45b, and refers to the physical ports 41b-1, 41b-2, 4b associated with the VLAN-ID "1001". -3 is detected.

Further, the physical port 41b-2 that has taken in the control packet is a port corresponding to the spanning tree leaf. Therefore, the autonomous transfer processing unit 44b refers to the autonomous transfer rule information, assigns the VLAN-ID "1001" to the control packet, and transfers the control packet to the physical port 41b-1, which is a port near the root of the spanning tree. do.

The physical port 41b-1 sends a control packet via the physical line 6a-3. The physical port 41a-3 of the autonomous transfer device 4a receives a control packet via the physical line 6a-3 (step Sa5). The physical port 41a-3 outputs the received control packet to the autonomous transfer processing unit 44a. The autonomous transfer processing unit 44a captures the control packet output by the physical port 41a-3. The captured control packet is already given information about the autonomous transfer device 4b. Therefore, the autonomous transfer processing unit 44a does not add the given information to the control packet to which the given information is given.

The autonomous transfer processing unit 44a refers to the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45a, and refers to the control packet via the logical path 60 associated with the physical port 41a-3 that has captured the control packet. Is transferred (step Sa6). Specifically, the transfer is performed as follows. The VLAN-ID "1001" is assigned to the control packet captured by the autonomous transfer processing unit 44a. Therefore, the autonomous transfer processing unit 44a refers to the autonomous transfer rule information stored in the autonomous transfer rule storage unit 45a, and refers to the physical ports 41a-1, 41a-2 associated with the VLAN-ID "1001". , 41a-3 are detected.

Further, the physical port 41a-3 that has taken in the control packet is a port corresponding to the spanning tree leaf. Therefore, the autonomous transfer processing unit 44a refers to the autonomous transfer rule information and transfers the control packet to the physical port 41a-1 corresponding to the root of the spanning tree.

The physical port 41a-1 sends a control packet via the physical line 6a-1. The autonomous transfer device transmission / reception unit 31 of the OpenFlow switch 3 receives a control packet via the physical line 6a-1 (step Sa7).

The autonomous transfer device transmission / reception unit 31 of the OpenFlow switch 3 outputs the received control packet to the transfer processing unit 35. The transfer processing unit 35 refers to the transfer rule information stored in the transfer rule storage unit 34, and identifies the control packet from which the VLAN-ID "1001" is removed from the control packet and the physical port of the received autonomous transfer device transmission / reception unit 31. Generate a Packet-In message containing information. The transfer processing unit 35 transmits the generated Packet-In message to the transfer control device 2 via the transfer control device transmission / reception unit 36 (step Sa8). The transfer processing unit 35 does not have to remove the VLAN-ID when transferring the control packet.

The transfer control device 2 receives the Packet-In message transmitted by the transfer control device transmission / reception unit 36 (step Sa9). The transfer control device 2 has the identification information of the autonomous transfer device 4b included in the grant information given to the control packet included in the Packet-In message, and the physical port of the physical port 41b-2 that has captured the control packet. The identification information and the identification information of the communication device 5a included in the control packet are read out, and the read information is recorded in the internal storage area (step Sa10).

For example, the transfer control device 2 generates a table having three items of "communication device", "connection destination device", and "connection destination port" shown in FIG. The transfer control device 2 refers to the generated table with the information shown in the first row shown in FIG. 4, that is, the identification information of the communication device 5a, the identification information of the autonomous transfer device 4b, and the physical port 41b-2. Write the physical port identification information.

By performing the same processing in the communication device 5b as in the case of the communication device 5a, the information shown in the second row of the table shown in FIG. 4 is recorded. As a result, in the transfer control device 2, the communication device 5a is connected to the physical port 41b-2 of the autonomous transfer device 4b by referring to the table shown in FIG. 4, and the communication device 5b is connected to the autonomous transfer device 4a. It can be recognized that it is connected to the physical port 41a-2 of.

In the configuration of the first embodiment described above, the physical ports 41a-2, 41b-that are physical ports included in the autonomous transfer devices 4a and 4b and are allowed to be connected to the communication devices 5a and 5b with the OpenFlow switch 3 as the starting point. A logical path 60 of a spanning tree having 2,41b-3 as leaves is generated. The communication devices 5a and 5b are connected to the physical ports 41a-2 and 41b-2 of the autonomous transfer devices 4a and 4b, and send a control packet containing the identification information of the own device to the connected autonomous transfer devices 4a and 4b. .. When the communication devices 5a and 5b are connected to the physical ports 41a-2 and 41b-2 of the own device and the control packets are received from the communication devices 5a and 5b, the autonomous transfer devices 4a and 4b receive the control packets. The physical port identification information for identifying the physical ports 41a-2 and 41b-2 and the identification information of the own device are added to the control packet, and the control packet is transmitted via the logical path 60. The OpenFlow switch 3 transfers the control packet received via the logical path 60 to the transfer control device 2. The transfer control device 2 receives the control packet, and the identification information and the physical port identification information of the autonomous transfer devices 4a and 4b added to the received control packet, and the communication devices 5a and 5b included in the control packet. And read out the identification information of.

Thereby, the transfer control device 2 can specify the transfer device (for example, the autonomous transfer device 4a, 4b or the OpenFlow switch 3) to which the communication device is newly connected and its physical port. As a result, the newly connected communication device can be connected to the transfer control device 2. Therefore, even a communication device that cannot operate an OpenFlow agent, a DHCP client, or the like can be connected to the transfer control device 2 by a simple method.

(Second embodiment)
FIG. 5 is a block diagram showing a configuration of the packet transfer system 1b according to the second embodiment. In FIG. 5, the same configurations as those of the packet transfer systems 1 and 1a shown in FIGS. 1 and 2 are designated by the same reference numerals, and different configurations will be described below. The packet transfer system 1b includes a transfer control device 2b, an OpenFlow switch 3, autonomous transfer devices 4a and 4b, and a communication device 5ab.

The transfer control device 2b has the following configurations in addition to the configurations of the transfer control device 2. The transfer control device 2b generates a control packet transmission instruction packet. The control packet transmission instruction packet is a packet including an instruction for transmitting a control packet to a communication device newly connected to a transfer device such as the OpenFlow switch 3 or the autonomous transfer devices 4a and 4b. The transfer control device 2b transmits a Packet-Out message including an instruction to send a control packet transmission instruction packet from the autonomous transfer device transmission / reception unit 31 of the OpenFlow switch 3 and a generated control packet transmission instruction packet to the OpenFlow switch 3. ..

The communication device 5ab is, for example, a modular communication device, like the communication devices 5, 5a, 5b of the first embodiment. The communication device 5ab has a configuration different from that of the communication devices 5, 5a, 5b in the following points. When the communication device 5ab receives the control packet transmission instruction packet, the communication device 5ab transmits a control packet including the identification information of the own device.

(Connection configuration collection process by the packet transfer system of the second embodiment)
FIG. 6 is a sequence diagram showing a partial flow of processing for collecting the connection configuration of the communication device 5ab by the packet transfer system 1b shown in FIG.

The transfer control device 2b generates a control packet transmission instruction packet. The transfer control device 2b transmits a Packet-Out message including an instruction to send a control packet transmission instruction packet from the autonomous transfer device transmission / reception unit 31 of the OpenFlow switch 3 and a generated control packet transmission instruction packet to the OpenFlow switch 3. (Step Sb1).

The transfer control device transmission / reception unit 36 of the OpenFlow switch 3 receives the Packet-Out message transmitted by the transfer control device 2b (step Sb2), and the transfer control device transmission / reception unit 36 receives the received Packet-Out message in the transfer processing unit 35. Output to. The transfer processing unit 35 captures the Packet-Out message output by the transfer control device transmission / reception unit 36.

The transfer processing unit 35 transmits the control packet transmission instruction packet from the physical port 31 according to the instruction to transmit the control packet transmission instruction packet from the autonomous transfer device transmission / reception unit 31 included in the Packet-Out message (step Sb2). ).

The autonomous transfer device transmission / reception unit 31 transmits a control packet transmission instruction packet via the physical line 6a-1. The physical port 41a-1 of the autonomous transfer device 4a receives the control packet transmission instruction packet via the physical line 6a-1 (step Sb4). The physical port 41a-1 outputs the received control packet transmission instruction packet to the autonomous transfer processing unit 44a.

The autonomous transfer processing unit 44a transmits a control packet transmission instruction packet from a physical port other than the physical port (here, physical port 41a-1) that has received the control packet transmission instruction packet (step Sb5). As a result, the control packet transmission instruction packet is transmitted to the physical ports 41a-2 and 41a-3. No device is connected to the physical port 41a-2. Therefore, the control packet transmission instruction packet is not transmitted from the physical port 41a-2.

The physical port 41a-3 transmits a control packet transmission instruction packet via the physical line 6a-3. The physical port 41b-1 of the autonomous transfer device 4b receives the control packet transmission instruction packet via the physical line 6a-3 (step Sb6). The physical port 41b-1 outputs the received control packet transmission instruction packet to the autonomous transfer processing unit 44b.

The autonomous transfer processing unit 44b transmits a control packet transmission instruction packet from a physical port other than the physical port (here, physical port 41b-1) that has received the control packet transmission instruction packet (step Sb6). As a result, the control packet transmission instruction packet is transmitted to the physical ports 41b-2 and 41b-3. None of the devices are connected to physical port 41b-3. Therefore, the control packet transmission instruction packet is not transmitted from the physical port 41b-3.

The physical port 41b-2 transmits a control packet transmission instruction packet via the physical line 6b-2. The communication device 5ab receives the control packet transmission instruction packet via the physical line 6b-2 (step Sb8). The communication device 5ab sends a control packet including the identification information of the own device to the physical line 6b-2. After that, the processes of steps Sa2 to Sa10 shown in FIG. 3 are performed. As a result, the transfer control device 2b acquires the information shown in the first row of the table shown in FIG. 4, as in the transfer control device 2 of the first embodiment.

In the second embodiment described above, when the communication device 5ab receives the packet transmission instruction packet without transmitting the control packet at regular intervals, the control packet is transmitted. Therefore, it is not necessary for the communication device 5ab to be equipped with a clock or the like for transmitting control packets at regular intervals. In the case of the communication devices 5, 5a and 5b of the first embodiment, a large number of control packets may be sent due to a malfunction, but in the communication device 5ab of the second embodiment, the control packet transmission instruction packet is sent. Since the control packet is transmitted at the timing of receiving the control packet, it is possible to suppress the transmission of unnecessary control packets as compared with the first embodiment.

Further, the format of the control packet transmission instruction packet may be the same as that of the control packet. In this case, since the communication device 5ab only needs to send back the received control packet transmission instruction packet without generating a new control packet, the function of the communication device 5ab can be further reduced.

In the second embodiment, when the transfer control device 2b generates the control packet transmission instruction packet, the control packet transmission instruction packet may be generated including the information indicating the format of the logical path 60. As a result, when the communication device 5ab receives the control packet transmission instruction packet, the communication device 5ab can generate a control packet based on the information indicating the format of the logical path 60 included in the control packet transmission instruction packet.

For example, it is assumed that the OpenFlow switch 3 and the autonomous transfer devices 4a and 4b change the format of the logical path 60. The OpenFlow switch 3 transmits information in the form of the changed logical path 60 to the transfer control device 2b. As a result, the transfer control device 2b can notify the communication device 5ab of the format of the changed logic path 60 by the control packet transmission instruction packet, so that the communication device 5ab changes the format of the logic path 60. Can be flexibly followed.

Here, as a format of the logical path 60, for example, there is a VLAN-ID. In the first and second embodiments described above, the configuration is not shown as a configuration in which a VLAN-ID is assigned to the communication devices 5, 5a, 5b, 5ab in advance, but the communication devices 5, 5a, 5b, 5ab have a logic path 60. It is also possible to register the VLAN-ID "1001" in advance. In this case, the autonomous transfer processing unit 44a of the autonomous transfer device 4b does not need to assign a VLAN-ID to the control packet captured via the physical port 41b-2. In such a configuration, for example, when the VLAN-ID is changed from "1001" to "1002", the change of the VLAN-ID can be notified to the communication device 5ab by the control packet transmission instruction packet. ..

(Third embodiment)
FIG. 7 is a block diagram showing a configuration of the packet transfer system 1c according to the third embodiment. In FIG. 7, the same configurations as those of the packet transfer systems 1, 1a and 1b shown in FIGS. 1, 2 and 5 are designated by the same reference numerals, and different configurations will be described below. The packet transfer system 1c includes a transfer control device 2c, an OpenFlow switch 3, 3c, an autonomous transfer device 4a, and a communication device 5ab.

The OpenFlow switch 3c has the same internal configuration as the OpenFlow switch 3 shown in FIG. Hereinafter, in the OpenFlow switch 3c, when each of the functional units corresponding to the functional units included in the OpenFlow switch 3 is shown, the code of each functional unit is indicated by a reference numeral “c”.

The OpenFlow switch 3c includes a transfer control device transmission / reception unit 36c, a transfer processing unit 35c, a transfer rule storage unit 34c, a search logic path generation unit 32c, an external transmission / reception unit 37c-1, 37c-2, and an autonomous transfer device transmission / reception unit 31c-. It is equipped with 1,31c-2.

The transfer control device transmission / reception unit 36c is connected to the transfer control device 2c via the physical line 7c. The transfer control device transmission / reception unit 36c establishes a secure channel connection with the transfer control device 2c, and transmits / receives data according to the OpenFlow protocol. The autonomous transfer device transmission / reception unit 31c-1 is connected to the physical port 41a-3 of the autonomous transfer device 4a by a physical line 6a-3. A communication device 5ab is connected to the external transmission / reception unit 37c-2 via the physical line 6b-2.

The search logic path generation unit 32c of the OpenFlow switch 3c generates a logic path composed of spanning trees according to the instruction of the transfer control device 2c. The search logic path generation unit 32c is preset so that the OpenFlow switch 3c does not serve as the starting point of the spanning tree.

As shown in FIG. 7, it is assumed that the same logical path 60 as in the first and second embodiments is generated in the packet transfer system 1c of the third embodiment. It is assumed that the VLAN-ID "1001" is used to generate the logical path 60. In this case, the search logical path generation unit 32c of the OpenFlow switch 3c receives the transfer rule information stored in the transfer rule storage unit 34c by the autonomous transfer device transmission / reception unit 31c-1 and the external transmission / reception units 37c-1, 37c-. The identification information of 2 is written in association with the VLAN-ID "1001".

The transfer control device 2c has the following configuration in addition to the configuration of the transfer control device 2b. When the OpenFlow switch 3c receives the control packet, the transfer control device 2c transmits the transfer rule information including the instruction to transfer the control packet received to the transfer control device 2b by the Packet-In message to the OpenFlow switch 3c. The transfer control device transmission / reception unit 36c receives the transfer rule information transmitted by the transfer control device 2c, and outputs the received transfer rule information to the transfer processing unit 35c. The transfer processing unit 35c writes the transfer rule information output by the transfer control device transmission / reception unit 36c to the transfer rule storage unit 34c.

(Connection configuration collection process by the packet transfer system of the third embodiment)
In the third embodiment, as in the second embodiment, the process of transmitting the control packet transmission instruction packet shown in FIG. 6 from the transfer control device 2c is started. In steps Sb1 to Sb5, the transfer control device 2c, the OpenFlow switch 3, and the autonomous transfer device 4a perform the same processing as in the second embodiment. Regarding the processing of steps Sb6 and Sb7, the OpenFlow switch 3c performs the same processing instead of the autonomous transfer device 4b. In step Sb8, the communication device 5ab receives the control packet transmission instruction packet transmitted by the external transmission / reception unit 37c-1 of the OpenFlow switch 3c to the physical line 6b-2.

FIG. 8 is a sequence diagram showing a flow of processing performed after the communication device 5ab receives the control packet transmission instruction packet in the third embodiment. The communication device 5ab sends a control packet including the identification information of the own device to the physical line 6b-2 (step Sd1).

The external transmission / reception unit 37c-1 of the OpenFlow switch 3c receives the control packet transmitted by the communication device 5ab. The external transmission / reception unit 37c-1 outputs the received control packet to the transfer processing unit 35c (step Sd2).

The transfer processing unit 35c refers to the transfer rule information stored in the transfer rule storage unit 34c. The forwarding rule information stored in the forwarding rule storage unit 34c defines an instruction to forward the control packet to the forwarding control device 2c by a Packet-In message. The transfer rule information includes information regarding the VLAN-ID "1001". However, it is assumed that the instruction to transfer the control packet to the transfer control device 2c by the Packet-In message has priority. In this case, the transfer processing unit 35c does not transfer the control packet via the logical path 60. The transfer processing unit 35c transmits a Packet-In message including a control packet and a physical port identification information that identifies the received external transmission / reception unit 37c-1 to the transfer control device 2c via the transfer control device transmission / reception unit 36c. (Step Sd3).

The transfer control device 2c receives the Packet-In message transmitted by the transfer control device transmission / reception unit 36c (step Sd4). The transfer control device 2c detects that the device that has received the control packet is the OpenFlow switch 3c by referring to the information of the source of the Packet-In message. The transfer control device 2c can acquire the information of the physical port to which the communication device 5ab is connected from the physical port identification information of the external transmission / reception unit 37c-1 included in the Packet-In message. The transfer control device 2c can acquire the identification information of the communication device 5ab by referring to the control packet included in the Packet-In message.

Therefore, the transfer control device 2c acquires a combination of three pieces of information recorded in the table having the items of "communication device", "connection destination device", and "connection destination port" shown in FIG. 4 from the Packet-In message. be able to. The transfer control device 2c records the acquired three pieces of information in the table of the internal storage area (step Sd5).

In the configuration of the third embodiment described above, the OpenFlow switch 3c is connected to the autonomous transfer device 4a, and the logical path 60 is connected to the physical port included in the OpenFlow switch 3c, that is, the external transmission / reception unit and the communication device 5ab. The OpenFlow switch 3c is connected to the transfer control device 2c by a physical line 7c which is a route other than the logical path 60. The communication device 5ab is connected to the OpenFlow switch 3c. When the OpenFlow switch 3c receives the control packet transmitted by the communication device 5ab, the OpenFlow switch 3c uses the transfer rule information stored in the transfer rule storage unit 34c together with the physical port identification information that identifies the external transmission / reception unit 37c-1 that received the control packet. Based on this, a control packet is sent to the transfer control device 2c via the physical line 7c.

As a result, even if the communication device 5ab that does not have a port dedicated to management and the OpenFlow agent or DHCP client is not operating is connected to the OpenFlow switch 3c in which the OpenFlow agent is operating, the communication device 5ab and the OpenFlow switch 3c are connected. It is possible to detect the connection configuration with. The OpenFlow switch 3c connected to the communication device 5ab does not transfer the control packet to the device higher than the logical path 60, but directly transmits the control packet to the transfer control device 2c by the Packet-In message. Therefore, the control packet is not transferred to the autonomous transfer device 4a and the OpenFlow switch 3 existing above the logical path 60, so that the bandwidth utilization rate can be improved as compared with the configuration of the second embodiment. ..

In the first to third embodiments described above, the starting point of the logical paths 60, 61, 62 is set to the OpenFlow switch 3, but the starting point of the logical paths 60, 61, 62 is set to the transfer control devices 2, 2b. , 2c may be used. In this case, the transfer of the control packet from the OpenFlow switch 3 to the transfer control devices 2, 2b, 2c is performed via the logical paths 60, 61, that is, based on the VLAN-ID. The transfer of the control packet transmission instruction packet from the transfer control devices 2b and 2c to the OpenFlow switch 3 is also performed based on the VLAN-ID.

In the first to third embodiments described above, the generation of the logic paths 60, 61, 62 is performed by the search logic path generation units 32, 32c and the autonomous search according to the instructions of the transfer control devices 2, 2b, 2c. Although it is designed to be performed by the logical path generation units 42a and 42b, the generation of the logical path does not have to be limited to this. For example, when the configuration is not complicated, the administrators of the packet transfer systems 1a, 1b, and 1c may generate the logical paths 60, 61, and 62 so as to configure the spanning tree. In this case, the administrator decides to add information about the VLAN-ID to the forwarding rule information stored in the forwarding rule storage units 34 and 34c and the autonomous forwarding rule information stored in the autonomous forwarding rule storage units 45a and 45b. Become.

A logical path may be set for each transfer device so that the transfer control devices 2, 2b, 2c form a spanning tree. In this configuration, the OpenFlow switches 3 and 3c do not have to include the search logic path generator 32, and the autonomous transfer devices 4, 4a and 4b do not have to include the search logic path generator 42. good. Instead, the transfer control devices 2, 2b, 2c include a logic path generator for constructing a spanning tree.
In the first to third embodiments described above, the control packet includes the identifiers of the communication devices 5, 5a, 5b, and 5ab, but the control packet contains the identifiers of the communication devices 5, 5a, 5b, and 5ab. May not be included. When configured in this way, the communication devices 5, 5a, 5b, and 5ab communicate at regular intervals from the time when the power is turned on and started, or in response to an instruction from the outside (for example, a transfer control device). A control packet that does not include the identifiers of the devices 5, 5a, 5b, and 5ab is transmitted.

In the first to third embodiments described above, it is assumed that the OpenFlow protocol among the SDNs is operating in the transfer control devices 2, 2b, 2c and the OpenFlow switches 3, 3c, but the OpenFlow protocol is shown. An SDN communication protocol other than the above may be operating.

In the first to third embodiments described above, the packet transfer systems 1, 1a, 1b, 1c have an OpenFlow switch (for example, OpenFlow switches 3, 3c) and an autonomous transfer device (for example, 4, 4a, 4b). Although the configuration including both is shown, the packet transfer system 1, 1a, 1b, 1c may be configured to include any one of the transfer devices. Taking FIG. 2 as an example of such a configuration, the packet transfer system 1a includes a transfer device of either the OpenFlow switch 3 or the autonomous transfer devices 4a and 4b. Then, the packet transfer system 1a sets a spanning tree-shaped logic path rooted in the transfer control device 2 in the transfer device provided.

The transfer control devices 2, 2b, 2c, the OpenFlow switches 3, 3c, and the autonomous transfer devices 4, 4a, 4b according to the first to third embodiments described above may be realized by a computer. In that case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, and a storage device such as a hard disk built in a computer system. Further, a "computer-readable recording medium" is a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and dynamically holds the program for a short period of time. It may also include a program that holds a program for a certain period of time, such as a volatile memory inside a computer system that is a server or a client in that case. Further, the above program may be for realizing a part of the above-mentioned functions, and may be further realized for realizing the above-mentioned functions in combination with a program already recorded in the computer system. It may be realized by using a programmable logic device such as FPGA (Field Programmable Gate Array).

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and the design and the like within a range not deviating from the gist of the present invention are also included.

It can be applied to a communication network in which a device having an SDN communication protocol and a device not having an SDN communication protocol are interconnected.

1 ... Packet transfer system, 2 ... Transfer control device, 3 ... OpenFlow switch, 4 ... Autonomous transfer device, 5 ... Communication device, 31 ... Autonomous transfer device transmission / reception unit, 32 ... Search logic path generation unit, 34 ... Transfer Rule storage unit, 35 ... Transfer processing unit, 36 ... Transfer control device transmission / reception unit, 37 ... External transmission / reception unit, 41-1 to 41-N ... Physical port, 42 ... Autonomous search logic path generation unit, 44 ... Autonomous type Transfer processing unit, 45 ... Autonomous transfer rule storage unit

Claims (7)

1. A packet transfer system including a transfer control device that controls packet transfer, a transfer device that transfers the packet based on a transfer rule defined by the transfer control device, and a communication device newly connected to the transfer device. There,
   The communication device sends a control packet to the transfer device,
   The transfer device assigns the physical port identification information for identifying the physical port that received the control packet and the identification information of the own device to the control packet transmitted from the communication device, and performs the transfer control. Transfer to the device
   The transfer control device acquires the identification information of the transfer device and the physical port identification information attached to the control packet.
   Packet forwarding system.
2. The transfer device is a physical port included in the transfer device, the transfer processing unit of each transfer device is a section, the physical port that allows connection to the communication device is a leaf, and the transfer device is connected to the transfer control device. The logical path of the spanning tree rooted in the transfer processing unit is generated,
   The packet transfer system according to claim 1.
3. Further provided with an autonomous transfer device that directly or indirectly connects to the transfer device and forwards packets based on autonomous transfer rules.
   The transfer device is connected to the autonomous transfer device, and a logical path is generated in a physical port included in the transfer device that allows connection to the communication device. Further, the transfer device is logical. It is connected to the transfer control device by a route other than the path,
   When the transfer device receives the control packet transmitted by the communication device, the transfer device requests to send the control packet to the transfer control device through a route other than the logical path based on the transfer rule defined by the transfer control device. Item 1. The packet transfer system according to Item 1.
4. When the power is turned on while the communication device is connected to the transfer device, the communication device sends the control packet to the connected transfer device at predetermined intervals.
   The packet transfer system according to any one of claims 1 to 3.
5. The transfer control device transmits a control packet transmission instruction packet via the transfer device.
   When the communication device receives the control packet transmission instruction packet, the communication device transmits the control packet.
   The packet transfer system according to any one of claims 1 to 4.
6. The transfer control device is
   Information indicating the format of the logical path for transmitting the control packet transmission instruction packet is included in the control packet transmission instruction packet.
   The communication device is
   When the control packet transmission instruction packet is received, the control packet corresponding to the information indicating the format of the logic path included in the control packet transmission instruction packet is generated, and the generated control packet is transmitted to the logic path. do,
   The packet transfer system according to claim 5.
7. In a packet transfer system including a transfer control device that controls packet transfer, a transfer device that transfers the packet based on a transfer rule defined by the transfer control device, and a communication device newly connected to the transfer device. It ’s a packet forwarding method.
   The communication device sends a control packet to the transfer device,
   The transfer device assigns the physical port identification information for identifying the physical port that received the control packet and the identification information of the own device to the control packet transmitted from the communication device, and performs the transfer control. Transfer to the device
   The transfer control device acquires the identification information of the transfer device and the physical port identification information attached to the control packet.
   Packet forwarding method.

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