Source: https://patents.google.com/patent/JP5381194B2/en
Timestamp: 2020-01-21 12:15:50
Document Index: 452327633

Matched Legal Cases: ['art 1', 'art 1', 'art 1', 'art 2', 'art 1', 'art 2', 'art 2']

JP5381194B2 - Communication program, relay node, and communication method - Google Patents
Communication program, relay node, and communication method Download PDF
JP5381194B2
JP5381194B2 JP2009063492A JP2009063492A JP5381194B2 JP 5381194 B2 JP5381194 B2 JP 5381194B2 JP 2009063492 A JP2009063492 A JP 2009063492A JP 2009063492 A JP2009063492 A JP 2009063492A JP 5381194 B2 JP5381194 B2 JP 5381194B2
JP2009063492A
JP2010219812A (en
和樹 兵頭
2009-03-16 Application filed by 富士通株式会社 filed Critical 富士通株式会社
2009-03-16 Priority to JP2009063492A priority Critical patent/JP5381194B2/en
2010-09-30 Publication of JP2010219812A publication Critical patent/JP2010219812A/en
2014-01-08 Publication of JP5381194B2 publication Critical patent/JP5381194B2/en
2029-03-16 Anticipated expiration legal-status Critical
The present disclosure relates to a communication program for transferring information, a relay node, and a communication method.
In recent years, modularization for each function is performed in machine control devices such as automobiles, industrial robots, and humanoid robots. In addition, with the advent of sensors having a network function, it has become common for terminal devices (modules) mounted on machine control devices to form a network.
In a machine control device including such a network, real-time communication and non-real-time communication are usually mixed. Here, the real-time communication is, for example, communication with a small absolute delay that is periodically executed for feedback control. Non-real-time communication is communication that requires high throughput but does not require real-time performance such as distribution of a correction program and file transfer.
On the other hand, in a machine control device including a network, a general-purpose network (for example, Ethernet (registered trademark)) including an aggregation / distribution device such as a switch device in a route from the viewpoint of flexibility of system configuration, expandability, and ease of construction. ) Is desired.
However, generally, in a switch device, when a plurality of inputs transferred to the same output terminal exceed the throughput of the output terminal, the communication queue in the switch apparatus grows. Therefore, in a network including a switch device in the middle of a route, there is a problem that it is difficult to execute real-time communication properly because there is a possibility that communication delay increases and packet loss may occur due to the growth of the communication queue. there were.
Therefore, conventionally, there is a technique for distinguishing temporally the implementation periods of real-time communication and non-real-time communication using the periodicity of real-time communication. Specifically, the terminal device on the receiving side monitors the communication status of data to itself, thereby detecting non-real-time communication that interferes with real-time communication and limiting the flow rate of non-real-time communication to switch device Prevent communication queue growth.
Japanese Patent Laid-Open No. 10-107769
However, the above-described conventional technology does not consider a topology in which terminal devices that transmit and receive data are connected via a plurality of switch devices. For this reason, in a network including a plurality of switch devices on a path connecting terminal devices, it is difficult to control the flow rate of non-real-time communication, and real-time communication may not be performed properly. is there.
In addition, if a network system cannot be constructed using a plurality of switch devices, the maximum number of connectable terminal devices is limited, and there is a problem that the flexibility and expandability of the system configuration is reduced. Here, the problem of the prior art will be described with reference to FIG.
FIG. 22 is an explanatory diagram showing the problems of the prior art. In the network system 2200, terminal devices 2201 to 2203 and terminal devices 2204 to 2206 are connected via switch devices 2210 and 2220. Here, for the sake of explanation, the terminal devices 2201 to 2203 are assumed to be transmission sides, and the terminal devices 2204 to 2206 are assumed to be reception sides.
In the network system 2200, data transmitted from the transmission side to the reception side collide between the switch device 2210 and the switch device 2220. At this time, data transmitted from the terminal devices 2201 and 2202 to the terminal device 2204 can be detected by the terminal device 2204.
However, the data transmitted from the terminal device 2203 to the terminal device 2206 cannot be detected by the terminal device 2204. Therefore, it is difficult to correctly control the flow rate by detecting non-real time communication that interferes with real time communication on the receiving side. As a result, the communication queue increases in the switch device 2210, and data relating to real-time communication may not be processed within a specified time.
In order to solve the above-described problems caused by the conventional technology, the disclosed technology is capable of reducing collision between real-time communication and non-real-time communication performed between nodes in a network, a relay node, and An object is to provide a communication method.
In order to solve the above-described problem and achieve the object, the present disclosure provides the first in a network that performs real-time communication between the nodes via a relay device that connects the first and second nodes. The own node selected from the node group of the node sets a path from the own node to the other node selected from the second node group, and excludes the own node from the first node group From the remaining nodes, the local node receives data related to non-real-time communication with respect to the remaining nodes other than the other nodes in the second node group, and the received data is set using the set route, It is characterized in that it is transferred from its own node to the other node.
According to the present disclosure, one non-real-time communication between nodes executed via a relay device is performed using a virtual link set between nodes respectively selected from the first and second node groups. Can be controlled together.
According to the communication program, the relay node, and the communication method, there is an effect that collision between real-time communication and non-real-time communication performed between nodes in the network can be reduced.
It is explanatory drawing which shows the outline | summary of this communication method. It is a system configuration diagram (part 1) of the network system according to the embodiment. It is a block diagram which shows the hardware constitutions of the node concerning embodiment. It is explanatory drawing (the 1) which shows an example of the memory content of an address table. It is explanatory drawing (the 2) which shows an example of the memory content of an address table. It is explanatory drawing which shows an example of the memory content of a transmission destination table. It is a block diagram which shows the functional structure of a relay node. It is explanatory drawing which shows an example of the data structure of non-real time data. It is explanatory drawing which shows the specific example of a correspondence table. It is explanatory drawing which shows an example of the memory content of a reception condition table. It is explanatory drawing (the 1) which shows an example of the memory content of an allocation table. It is explanatory drawing (the 2) which shows an example of the memory content of an allocation table. It is a block diagram which shows the functional structure of a normal node. It is a flowchart which shows an example of the communication processing procedure of a relay node. It is a flowchart which shows an example of the specific process sequence of the flow volume allocation process of step S1206. It is a flowchart which shows an example of the specific process sequence of the 1st transfer process of step S1207. It is a flowchart which shows an example of the 1st reception process procedure of a relay node. It is a flowchart which shows an example of the 2nd reception process procedure of a relay node. It is a flowchart which shows an example of the 2nd transfer processing procedure of a relay node. It is a flowchart which shows an example of the communication processing procedure of a normal node. It is a flowchart which shows an example of the specific process sequence of the non-real-time communication process of step S1810. It is a flowchart which shows an example of the real-time communication processing procedure of a normal node. It is a system configuration | structure figure (the 2) of the network system concerning an embodiment. It is explanatory drawing which shows the problem of a prior art.
Exemplary embodiments of a communication program, a relay node, and a communication method according to the present invention are explained in detail below with reference to the accompanying drawings.
(Outline of this communication method)
First, an outline of this communication method will be described. In this communication method, control is performed so that non-real-time communication does not interfere with real-time communication in a local network where real-time communication that is executed periodically and non-real-time communication that is executed irregularly are mixed.
FIG. 1 is an explanatory diagram showing an outline of this communication method. As shown in FIG. 1, in a certain local network, node groups N1 to N3 and node groups N4 to N6 are connected via switch devices SW1 and SW2. In this communication method, the following (1) to (4) are performed in a local network including a plurality of switch devices SW1 and SW2 as shown in FIG.
(1) Group nodes directly connected to the individual switch devices SW1, SW2. Here, a group A is formed by the node groups N1 to N3 directly connected to the switch device SW1, and a group B is formed by the node groups N4 to N6 directly connected to the switch SW2.
(2) A relay node that relays non-real-time communication between groups is installed for each of groups A and B. Here, the node N1 is selected from the node groups N1 to N3 as the relay node, and the node N4 is selected from the node groups N4 to N6. As a result, the non-real-time communication via the switch devices SW1 and SW2 is concentrated on the relay nodes N1 and N4.
(3) Using an existing virtual network technology, a virtual link (hereinafter referred to as “virtual link VL”) from the relay node N1 to the relay node N4 is set. Thereby, the non-real-time communication between the relay nodes N1 and N4 is integrated into one, and the collision with the real-time communication in the physical link L between the switch devices SW1 and SW2 is reduced.
(4) All nodes N1 to N6 are synchronized in order to share the implementation period of real-time communication and non-real-time communication with all nodes N1 to N6. Thereby, the implementation period of real-time communication and non-real-time communication can be distinguished, and it controls so that non-real-time communication does not interfere with real-time communication.
As described above, in this communication method, the non-real time communication between the groups via the switch devices SW1 and SW2 is collectively controlled by using the virtual link VL connecting the relay nodes N1 and N4. Reduce interference with communications. Although the relay nodes N1 and N4 are selected from the node groups N1 to N3 and N4 to N6 here, the present invention is not limited to this. For example, apart from the node groups N1 to N6, a relay node that relays non-real-time communication between the groups A and B may be dedicated.
(System configuration diagram of network system)
FIG. 2 is a system configuration diagram (part 1) of the network system according to the embodiment. In the network system 200, nodes N1 to N12 and switch devices SW1 to SW5 are communicably connected via a network 210 such as a LAN (Local Area Network).
Here, the nodes N1 to N12 are communication devices having a communication function (real-time communication, non-real-time communication). For example, the nodes N1 to N12 are ECUs (Electric Control Units), sensors, and actuators mounted on automobiles and robots. is there. The switch devices SW1 to SW5 are relay devices having a switching function. A detailed description of the switching function will be described later.
In the network system 200, groups G1 to G4 are formed by node groups N1 to N3, N4 to N6, N7 to N9, and N10 to N12 that are directly connected to the individual switch devices SW1 to SW4. In the network system 200, relay nodes N1, N4, N7, and N10 that relay non-real-time communication between groups are installed for each of the groups G1 to G4.
In the network system 200, virtual links VL1 to VL6 that connect the relay nodes are set. Specifically, virtual links VL1 to VL3 that connect the relay node N1 of the group G1 and the relay nodes N4, N7, and N10 of the groups G2 to G4 are set. In addition, virtual links VL4 and VL5 that connect the relay node N4 of the group G2 and the relay nodes N7 and N10 of the groups G3 and G4 are set. Furthermore, a virtual link VL6 that connects the relay node N7 of the group G3 and the relay node N10 of the group G4 is set.
(Node hardware configuration)
FIG. 3 is a block diagram of a hardware configuration of the node according to the embodiment. In FIG. 3, nodes N1 to N12 (hereinafter simply referred to as “node N”) include a CPU (Central Processing Unit) 301, a ROM (Read-Only Memory) 302, a RAM (Random Access Memory) 303, and an I / F (Interface) 304. Note that the node N may include a magnetic disk drive, a magnetic disk, an optical disk drive, and an optical disk. Each component is connected by a bus 300.
Here, the CPU 301 governs overall control of the node N. The ROM 302 stores a program such as a boot program. The RAM 303 is used as a work area for the CPU 301. An interface (hereinafter abbreviated as “I / F”) 304 is connected to a network 210 such as a LAN through a communication line, and is connected to other devices via the network 210. The I / F 304 controls an internal interface with the network 210 and controls data input / output from an external device.
The magnetic disk drive controls data read / write with respect to the magnetic disk according to the control of the CPU 301. The magnetic disk stores data written under the control of the magnetic disk drive. The optical disc drive controls reading / writing of data with respect to the optical disc according to the control of the CPU 301. The optical disk stores data written under the control of the optical disk drive, and allows the computer to read data stored on the optical disk.
(Address table storage contents)
Next, various address tables used by the node N will be described. The address table is stored in a storage device such as the ROM 302, RAM 303, magnetic disk, or optical disk shown in FIG. In the following, among all the nodes in the network 210, the node N that relays non-real-time communication is referred to as “relay node JN”, and the remaining nodes N excluding the relay node N are referred to as “normal node SN”. write.
FIG. 4A is an explanatory diagram (part 1) of an example of the contents stored in the address table. 4A, the address table 400 includes information indicating a node ID, a physical address, a system node address, a group node address, and a relay node for each node N. The address table 400 is held by each of the nodes N1 to N12 in the network system 200.
Here, the node ID is an identifier of the node N. The physical address is an address unique to the I / F 304 connected to the LAN, such as an Ethernet MAC address. The system node address is an address of the node N that is uniquely determined in the entire network system 200. The group node address is an address of a node N that is uniquely determined by each group G1 to G4 in the network system 200.
In the example of FIG. 4A, the first to third numbers out of the four numbers separated by the dot “.” Of the group node address are group numbers for identifying the groups G1 to G4. Is a node number for identifying the node N in the group. The notation “/ 3” indicates that the numbers up to the third are group numbers. By changing the number of numbers assigned to the group number and the node number, the number of groups in the system and the number of nodes in the group are adjusted.
FIG. 4B is an explanatory diagram (part 2) of an example of the contents stored in the address table. 4B, the address table 401 includes a node ID, a system node address, a corresponding physical address, a group node address, and a corresponding physical address. The address table 401 is held by the node N belonging to the group G1.
Here, each of the system node address and the group node address is associated with a physical address (corresponding physical address). Data in which the system node address or group node address is set is directly transmitted to the node N of the corresponding physical address. Also, data transmission for a group node address of a group different from the group to which the corresponding physical address does not exist and the group to which it belongs is transferred via the relay node.
The relay node is determined by preset information or a selection algorithm. One (or more) relay nodes are always determined from the group. When transmitting data to a group different from the group to which the other node belongs, the other nodes perform route setting so as to relay and transfer the determined relay node (see FIG. 4-3).
FIG. 4C is an explanatory diagram of an example of the contents stored in the transmission destination table. In FIG. 4C, the transmission destination table 402 shows the destination address and physical address of the node N that is the transmission destination of the node N belonging to the group G1 in association with each other.
(Functional configuration of relay node)
Next, a functional configuration of the relay node JN (for example, the nodes N1, N4, N7, and N10 in the network system 200) will be described. FIG. 5 is a block diagram illustrating a functional configuration of the relay node. In FIG. 5, the relay node JN includes a setting unit 501, a receiving unit 502, an associating unit 503, a transferring unit 504, a detecting unit 505, a calculating unit 506, an assigning unit 507, and a transmitting unit 508. It is the composition which includes. Specifically, the functions (setting unit 501 to transmission unit 508) serving as the control unit execute, for example, a program stored in a storage device such as the ROM 302, RAM 303, magnetic disk, or optical disk shown in FIG. Or the function is realized by the I / F 304.
The setting unit 501 has a function of setting a route from the own node selected from the first node group in the network 210 to the other node selected from the second node group. Here, the network 210 is a local network including a plurality of switch devices, for example. Each node group is a set of nodes directly connected to individual switch devices in the network 210.
In the following, when a specific example of each function is described, the node N1 in the network system 200 is assumed as the relay node JN. That is, the node groups N1 to N3 are the first node group, and the node groups N4 to N6, the node groups N7 to N9, and the node groups N10 to N12 are the second node group.
In this case, for example, assuming that the address table 400 of FIG. 4-1 is given as the system setting information, the setting unit 501 refers to the address table 400 and sets “Yes” in the field of the relay node excluding the own node N1. The other nodes N4, N7, and N10 for which “is set” are specified. Then, using the existing virtual network technology, the setting unit 501 sets virtual links VL1 to VL3 (see FIG. 2) that connect the own node N1 and other nodes N4, N7, and N10.
As the virtual network technology, for example, an overlay network can be used. However, a detailed description of the virtual link setting method is omitted because it is an existing technology. The setting result is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
The receiving unit 502 has a function of receiving data related to non-real time communication (hereinafter referred to as “non-real time data”) from the normal node SN in the first node group. Here, the non-real-time data is data that does not require real-time performance, for example, improved program correction data. Here, in particular, the non-real time data from the normal node SN of the first node group to the normal node SN of the second node group is targeted.
Specifically, for example, the receiving unit 502 receives non-real time data for the node N5 of the group G2 from the node N3 of the group G1 via the switch device SW1. The reception result is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
Here, the data structure of non-real time data will be described. FIG. 6 is an explanatory diagram showing an example of the data structure of the non-real time data. In FIG. 6, the data structure 600 has a header area and a data area. In the header area, a physical destination address, a logical destination address, and a data amount are set. Data exchanged by the application of each node N is written in the data area.
The physical destination address is a physical address indicating a direct transmission destination of non-real time data. The logical destination address is a logical address indicating the final destination of non-real time data. Specifically, the logical destination address corresponds to a system node address and a group node address. Here, a group node address that is valid only within each group is set as the logical destination address. The data amount is a data amount of non-real time data.
Note that the switch devices SW1 to SW4 shown in FIG. 2 transfer the received data to the destination node according to the designated physical destination address.
Returning to the description of FIG. 5, the associating unit 503 has a function of associating the received non-real time data with the set route. Note that the non-real-time data here is data received from the normal node SN of the first node group. Specifically, for example, the associating unit 503 creates a correspondence table 700 (see FIG. 7) for determining a transfer destination from a destination address based on the address table 400 given as system setting information.
FIG. 7 is an explanatory diagram showing a specific example of the correspondence table. In FIG. 7, the correspondence table 700 has a destination address field and a transfer destination field. By setting information in each field, the transfer destination of non-real time data is stored as a record.
In FIG. 7, “VLM-N” represents a virtual link from the group GM to the group GN. “VLM-N” and “VLN-M” represent the same virtual link. In FIG. 7, the transfer destination table is managed for each group number, although the transfer correspondence table for outside the group is described as having a transfer destination for each destination address.
Returning to the description of FIG. 5, the transfer unit 504 has a function of transferring the received non-real time data. Specifically, for example, the transfer unit 504 refers to the correspondence table 700 illustrated in FIG. 7 and transfers the received non-real time data to another node.
The detection unit 505 has a function of detecting a cycle start time of real-time communication that is periodically executed in the network 210. Specifically, for example, the detection unit 505 measures the time at its own node and detects the time when the real-time communication cycle start time is reached. However, the time interval of the real-time communication that is periodically executed is set in advance.
The transmission unit 508 has a function of transmitting a synchronization packet to another node as a result of detecting the period start time of real-time communication. Specifically, for example, the transmission unit 508 transmits a synchronization packet provided with an identifier for synchronizing the timing of executing real-time communication to another node. Thereby, synchronization can be established between the relay nodes JN in the network system 200.
Further, the transmission unit 508 transmits the synchronization packet to the normal node SN. As a result, all nodes in the group can be synchronized. That is, all nodes N1 to N12 can be synchronized by transmitting a synchronization packet to the remaining nodes N other than the own node in the network system 200 with the own node as a base point.
However, when receiving the synchronization packet from another node before the real-time communication cycle start time, the detection unit 505 detects the reception time of the synchronization packet as the real-time communication cycle start time. The detection result is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
The transfer unit 504 may transfer the non-real time data to another node at a time different from the detected cycle start time of the real time communication. This makes it possible to distinguish between execution timings of real-time communication and non-real-time communication, and avoids collision between real-time communication and non-real-time communication via relay devices (for example, switch devices SW1 to SW5). can do.
In the following, the time interval of periodically executed real-time communication is defined as a first cycle, and the time interval obtained by dividing the first cycle into M is defined as a second cycle for executing non-real-time data transfer processing. . However, the M is arbitrarily set according to the system requirements of the network system 200 and the like.
The receiving unit 502 has a function of receiving non-real time data from other nodes using the set route. Specifically, for example, the receiving unit 502 receives non-real time data from the node N4 using the virtual link VL1. In addition, the group node address of the normal node SN in the same group as the own node is set in the non-real time data transferred from another node.
FIG. 8 is an explanatory diagram of an example of the contents stored in the reception status table. In FIG. 8, the reception status table 800 has fields for virtual link ID and data flow rate, and stores the data flow rate for each of the virtual links VL1 to VL3 as a record. However, the data flow rate is the received amount of non-real time data received from another node in the previous phase of the second period. Further, the data flow rate is represented by, for example, a communication speed (Mbps, Kbps, etc.) per unit time.
In addition, the transfer unit 504 has a function of transferring the received non-real time data to the normal node SN. Specifically, for example, the transfer unit 504 transfers the received non-real time data to the group node address set in the non-real time data via the switch device SW1.
Thereby, the non-real time data from the normal node SN of another group can be transferred to the normal node SN in the same group. Further, the transfer unit 504 may transfer the non-real time data to the normal node SN according to the data flow rate assigned to the physical link PL that connects the local node and the normal node SN.
The calculation unit 506 has a function of calculating the data flow rate assigned to the set route based on the transmission capability of the network 210. Here, the transmission capability of the network 210 is, for example, the capacity of the physical link of the network system 200 (communication speed per unit time). Specifically, for example, the calculating unit 506 divides the physical link capacity by the set number of virtual links VL to calculate the data flow rate to be allocated to each virtual link VL.
As an example, the capacity of the physical link of the network system 200 is 12 [Mbps]. In this case, the data flow rate assigned to each of the virtual links VL1 to VL3 is 4 (= 12/3) [Mbps]. Thereby, the capacity of the physical link can be equally allocated to the virtual links VL1 to VL3. The calculation result is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
Further, the calculation unit 506 may calculate the data flow rate assigned to the set route based on the data flow rate of the non-real time data received from another node. Specifically, for example, the calculation unit 506 refers to the reception status table 800 illustrated in FIG. 8 and determines the virtual link VL1 based on the data flow rate of the non-real time data received from the other nodes N4, N7, and N10. Calculate the data flow rate assigned to VL3.
More specifically, for example, the data flow rate for each of the virtual links VL1 to VL3 is calculated so as not to exceed the capacity of the physical link and to make the most effective use. Thereby, the data flow rate allocated to the virtual links VL1 to VL3 can be dynamically controlled according to the communication status of the non-real time communication between the relay nodes. Since the technique for controlling the data flow rate allocated according to the communication status is an existing technology, a detailed description thereof is omitted.
The allocation unit 507 has a function of allocating the calculated data flow rate to the set route. Specifically, for example, the assignment unit 507 associates the virtual link VL connecting the node with another node and the data flow rate assigned to the virtual link VL and stores them in the assignment table 900 shown in FIG. Here, an example of the contents stored in the allocation table 900 will be described.
FIG. 9 is an explanatory diagram (part 1) of an example of the contents stored in the allocation table. In FIG. 9, an allocation table 900 has fields for virtual link ID and data flow rate, and stores allocation results for each of the virtual links VL1 to VL3 as records. The allocation table 900 is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
The transmission unit 508 has a function of transmitting the allocation result to another node. Specifically, for example, first, the transmission unit 508 refers to the allocation table 900 and specifies the data flow rate allocated to the virtual link VL that connects the own node and another node. Further, the transmission unit 508 refers to the address table 400 and identifies the system node address of another node. Then, the transmission unit 508 transmits the specified data flow rate to another node using the specified system node address.
In addition, the receiving unit 502 has a function of receiving, from another node, an assignment result assigned to a route from its own note to reaching another node. Note that the received allocation result of the virtual link VL is stored in the allocation table 1000 illustrated in FIG. 10 in association with the virtual link ID by the associating unit 503, for example.
FIG. 10 is an explanatory diagram (part 2) of an example of the contents stored in the allocation table. In FIG. 10, the allocation table 1000 has fields for virtual link ID and data flow rate, and stores allocation results for each of the virtual links VL1 to VL3 as records. The allocation table 1000 is stored in a storage device such as the RAM 303, a magnetic disk, or an optical disk.
In addition, the transfer unit 504 has a function of transferring non-real time data to another node according to the received allocation result. Specifically, for example, the transfer unit 504 refers to the allocation table 1000 and transfers the non-real time data to the node N4 so as not to exceed the data flow rate X ′ allocated to the virtual link VL1. Thereby, for example, non-real-time communication exceeding the capacity of the physical link in the network system 200 can be avoided, and an increase in the communication queue of the switch device SW1 can be suppressed.
(Functional configuration of normal node)
Next, a functional configuration of the normal node SN (for example, the nodes N2 and N3 in the group G1) will be described. FIG. 11 is a block diagram illustrating a functional configuration of a normal node. In FIG. 11, the normal node SN includes a first execution unit 1101, a second execution unit 1103, a transmission unit 1102, a reception unit 1104, a calculation unit 1105, and an allocation unit 1106. . Specifically, the functions (the first execution unit 1101 to the allocation unit 1106) serving as the control unit are, for example, programs stored in a storage device such as the ROM 302, the RAM 303, the magnetic disk, and the optical disk illustrated in FIG. The function is realized by causing the CPU 301 to execute it or by using the I / F 304.
The first execution unit 1101 has a function of executing real-time communication. Specifically, for example, the first execution unit 1101 controls the transmission unit 1102 to set the system node of the node N as a destination address, and data related to real-time communication (hereinafter referred to as “real-time data”). ).
Here, the real-time data is data that requires real-time characteristics, for example, data for feedback control. Note that the first execution unit 1101 periodically executes real-time communication at preset time intervals. However, the cycle start time of real-time communication is the reception time when the synchronization packet is received from the relay node JN in the same group.
The second execution unit 1103 has a function of executing non-real time communication. Specifically, for example, the second execution unit 1103 controls the transmission unit 1102, sets the group node address of the node N as the destination address, and transmits non-real time data. However, when transmitting non-real-time data to a node N in a different group, the data is transmitted to the node N via the relay node JN in the same group as the own node N.
In the following, when a specific example of each function is described, the node N2 in the network system 200 is assumed as the normal node SN.
The receiving unit 1104 has a function of receiving real time data and non-real time data. Specifically, for example, the reception unit 1104 receives real-time data or non-real-time data via the switch device SW1.
The calculation unit 1105 has a function of calculating a data flow rate to be allocated to a path connecting the own node and another node in the first node group based on the data flow rate of the received non-real time data. Here, the path connecting the own node and another node is a physical link PL that connects the node N2 and the nodes N1 and N3 connected via the switch device SW1.
Note that the calculation process performed by the calculation unit 1105 is the same as the calculation process performed by the calculation unit 506 of the relay node JN described above, and thus the description thereof is omitted here.
The allocating unit 1106 has a function of allocating the calculated data flow rate to a path connecting the own node and another node. Specifically, for example, the assigning unit 1106 associates and holds the physical link PL that connects the own node and another node and the data flow rate assigned to the physical link PL.
The transmission unit 1102 has a function of transmitting the allocation result to another node. Specifically, for example, the transmission unit 1102 refers to the address table 402 and identifies the system node address of another node. Then, the transmission unit 1102 transmits the data flow rate assigned to the physical link PL set between the own node and another node using the specified system node address.
In addition, the reception unit 1104 has a function of receiving, from another node, an assignment result assigned to a route from its own node to the other node. Then, the second execution unit 1103 executes the non-real time data according to the received allocation result. Specifically, for example, the second execution unit 1103 controls the transmission unit 1102 to transmit non-real time data to other nodes so as not to exceed the data flow rate allocated to the physical link VL.
(Relay node communication processing procedure)
Next, a communication processing procedure of the relay node JN will be described. However, of all the node groups in the network system 200, the other relay nodes JN other than the own node are expressed as “relay nodes JNi (i = 1, 2,..., N)”. Further, the normal node SN in the same group as the own node is denoted as “normal node SNj (j = 1, 2,..., M)”. The virtual links VL1 to VLn that connect the own node and the relay nodes JN1 to JNn are set in advance.
FIG. 12 is a flowchart illustrating an example of a communication processing procedure of the relay node. In the flowchart of FIG. 12, first, the detection unit 505 determines whether or not the time corresponding to the period interval of the first period has elapsed since the network system 200 was activated (step S1201).
Here, when the time interval of the first cycle has not elapsed (step S1201: No), the receiving unit 502 determines whether or not a synchronization packet has been received from the relay node JNi (step S1202). If no synchronization packet has been received (step S1202: No), the process returns to step S1201.
On the other hand, when the synchronization packet is received (step S1202; Yes), the detection unit 505 detects the reception time of the synchronization packet as the cycle start time of the first period (step S1203). Then, a flow rate assigning process for assigning a data flow rate to the virtual link VLi connecting the own node and the relay node JNi is executed (step S1206).
Thereafter, the transfer unit 504 executes a first transfer process for transferring the non-real time data to the relay node JNi using the virtual link VLi (step S1207). Next, it is determined whether or not there is an instruction to stop the network system 200 (step S1208).
Here, when there is no stop instruction (step S1208: No), it waits until the cycle start time of the second cycle is reached (step S1209: No). And when it becomes the period start time of a 2nd period (step S1209: Yes), it returns to step S1206.
In step S1201, when the time interval of the first cycle has elapsed (step S1201: Yes), the detection unit 505 sets the time elapsed for the time interval of the first cycle as the cycle start time of the first cycle. It detects (step S1204). Then, the transmission unit 508 transmits a synchronization packet to the relay nodes JN1 to JNn (step S1205), and the process proceeds to step S1206.
In step S1208, when there is an instruction to stop the network system 200 (step S1208: Yes), a series of processes according to this flowchart is ended. Note that the stop instruction for the network system 200 may be received at an arbitrary timing, for example.
<Flow rate allocation procedure>
Next, a specific processing procedure of the flow rate allocation processing in step S1206 shown in FIG. 12 will be described. FIG. 13 is a flowchart illustrating an example of a specific processing procedure of the flow rate allocation processing in step S1206.
In the flowchart of FIG. 13, it is first determined whether or not the current time is the cycle start time of the first cycle (step S1301). Here, in the case of the cycle start time of the first cycle (step S1301: Yes), the transmission unit 508 transmits a synchronization packet to the normal nodes SN1 to SNm (step S1302).
Thereafter, the allocation unit 507 allocates the data flow rate “0” to the virtual links VL1 to VLn that connect the own node and the relay nodes JN1 to JNn (step S1303). Then, the transmission unit 508 transmits the allocation result to the relay nodes JN1 to JNn (step S1304), and the process proceeds to step S1207 shown in FIG.
On the other hand, if it is determined in step S1301 that the current time is not the cycle start time of the first cycle (step S1301: No), i = 1 is set (step S1305), and it is determined whether i> n (step S1306). Here, if i ≦ n (step S1306: NO), the calculation unit 506 calculates the data flow rate to be allocated to the virtual link VLi (step S1307).
Then, the allocation unit 507 allocates the calculated data flow rate to the virtual link VLi (step S1308), and the transmission unit 508 transmits the allocation result to the relay node JNi (step S1309). Thereafter, i = i + 1 is set (step S1310), and the process returns to step S1306.
In step S1306, if i> n (step S1306: Yes), the process proceeds to step S1207 shown in FIG.
Thereby, the implementation period of real-time communication and non-real-time communication can be distinguished, and the collision with real-time communication and non-real-time communication can be avoided.
<First Transfer Processing Procedure>
Next, a specific processing procedure of the first transfer processing in step S1207 shown in FIG. 12 will be described. FIG. 14 is a flowchart illustrating an example of a specific processing procedure of the first transfer processing in step S1207.
In the flowchart of FIG. 14, first, i = 1 is set (step S1401), and it is determined whether i> n (step S1402). Here, if i ≦ n (step S1402: No), the transfer unit 504 refers to the allocation table 1000 to identify the data flow rate allocated to the virtual link VLi (step S1403).
Next, the transfer unit 504 reads the non-real time data corresponding to the virtual link VLi from the storage device with reference to the correspondence table 700 (step S1404). The transfer unit 504 transfers the read non-real-time data using the virtual link VLi according to the data flow rate specified in step S1403 (step S1405).
Thereafter, i = i + 1 is set (step S1406), and the process returns to step S1402. If i> n is satisfied (step S1402: Yes), the process proceeds to step S1208 shown in FIG.
Thereby, the data flow rate of non-real-time communication can be controlled according to the capacity of the physical link of the network 210 and the actual communication status.
<First Reception Processing Procedure>
Next, a processing procedure of a first reception process for receiving non-real time data from the normal node SNj in the same group will be described. FIG. 15 is a flowchart illustrating an example of a first reception processing procedure of the relay node. In the flowchart of FIG. 15, first, the receiving unit 502 determines whether or not non-real time data has been received from the normal node SNj (step S1501).
Here, after waiting for the reception of non-real time data (step S1501: No), if received (step S1501: Yes), the destination address set in the received non-real time data by the associating unit 503 The relay node JNi in the same group as the node N is identified (step S1502).
Thereafter, the associating unit 503 specifies the virtual link VLi that connects the local node and the specified relay node JNi (step S1503). Finally, the association unit 503 associates the data ID of the non-real time data and the virtual link ID of the virtual link VLi and stores them in the correspondence table 700 (step S1504), and ends the series of processes according to this flowchart.
Thereby, the virtual link VLi used for the transfer of the non-real time data can be specified from the plurality of virtual links VL1 to VLn.
<Second reception processing procedure>
Next, a processing procedure of a second reception process for receiving the assignment result assigned to the virtual link VLi connecting the own node and the relay node JNi will be described. FIG. 16 is a flowchart illustrating an example of a second reception processing procedure of the relay node. In the flowchart of FIG. 16, first, the receiving unit 502 determines whether or not an allocation result has been received from the relay node JNi (step S1601).
Here, after waiting for the allocation result to be received (step S1601: No), if it is received (step S1601: Yes), the associating unit 503 specifies the virtual link VLi that connects the local node and the relay node JNi ( Step S1602). Finally, the associating unit 503 associates the identified virtual link VLi with the received allocation result and stores it in the allocation table 1000 (step S1603), and ends the series of processes in this flowchart.
Thereby, the data flow rate of the non-real-time data allocated to each virtual link VL1 to VLn can be specified.
<Second transfer processing procedure>
Next, a processing procedure of a second transfer process for transferring non-real time data from the relay node JNi to the normal node SNj will be described. FIG. 17 is a flowchart illustrating an example of the second transfer processing procedure of the relay node.
In the flowchart of FIG. 17, first, the receiving unit 502 determines whether or not non-real time data has been received from the relay node JNi (step S1701). Here, it waits for the reception of non-real time data (step S1701: No), and when it is received (step S1701: Yes), the transfer unit 504 converts the received non-real time data into the non-real time data. Transfer to the set group node address (step S1702).
Thereby, non-real time data between different groups can be transferred via the relay node JN.
(Normal node communication processing procedure)
Next, the communication processing procedure of the normal node SN will be described. However, the remaining nodes N excluding the own node in the same group are expressed as “group node GNk (k = 1, 2,..., M)”. FIG. 18 is a flowchart illustrating an example of the communication processing procedure of the normal node. In the flowchart of FIG. 18, first, it is determined whether or not the current time is the cycle start time of the first cycle (step S1801).
Here, in the case of the cycle start time of the first cycle (step S1801: Yes), the allocation unit 1106 allocates the data flow rate “0” to the physical links VL1 to VLm that connect the local node and the group nodes GN1 to GNm ( Step S1802). Then, the transmission unit 1102 transmits the allocation result to the group nodes GN1 to GNm (step S1803), and the process proceeds to step S1810.
On the other hand, if it is determined in step S1801 that the current time is not the cycle start time of the first cycle (step S1801: No), k = 1 is set (step S1804), and it is determined whether k> m is satisfied (step S1805). If k ≦ m (step S1805: NO), the calculation unit 1105 calculates the data flow rate assigned to the physical link PLk (step S1806).
The allocation unit 1106 allocates the calculated data flow rate to the physical link PLk (step S1807), and the transmission unit 1102 transmits the allocation result to the group node GNk (step S1808). Thereafter, k = k + 1 is set (step S1809), and the process returns to step S1805.
In step S1805, if k> m (step S1805: Yes), the second execution unit 1103 executes non-real-time communication processing (step S1810). Next, it is determined whether or not there has been an instruction to stop the network system 200 (step S1811).
Here, when there is no stop instruction (step S1811: No), it waits until the cycle start time of the second cycle is reached (step S1812: No). When the cycle start time of the second cycle is reached (step S1812: Yes), the process returns to step S1801. In step S1811, when there is an instruction to stop the network system 200 (step S1811: Yes), the series of processes according to the flowchart ends.
As a result, it is possible to distinguish between execution periods of real-time communication and non-real-time communication, and to avoid collision between real-time communication and non-real-time communication.
<Non-real-time communication processing procedure>
Next, a specific processing procedure of the non-real time communication processing of step S1810 shown in FIG. 18 will be described. FIG. 19 is a flowchart illustrating an example of a specific processing procedure of the non-real time communication processing in step S1810.
In the flowchart of FIG. 19, first, k = 1 is set (step S1901), and it is determined whether or not k> m (step S1902). Here, if k ≦ m (step S1902: No), the second execution unit 1103 identifies the data flow rate assigned to the physical link PLk (step S1903).
Next, the second execution unit 1103 reads non-real time data corresponding to the physical link PLk from the storage device (step S1904). Then, the second execution unit 1103 controls the transmission unit 1102 to transmit the read non-real time data according to the data flow rate specified in step S1903 using the physical link PLk (step S1905).
Thereafter, k = k + 1 is set (step S1906), and the process returns to step S1902. If k> m is satisfied (step S1902: Yes), the process proceeds to step S1811 shown in FIG.
<Real-time communication processing procedure>
Next, the real-time communication processing procedure of the normal node SN will be described. FIG. 20 is a flowchart illustrating an example of a real-time communication processing procedure of a normal node. In the flowchart of FIG. 20, first, it is determined whether or not the current time is the cycle start time of the first cycle (step S2001).
Here, when the current time becomes the cycle start time of the first cycle (step S2001: No) and the cycle start time of the first cycle is reached (step S2001: Yes), the first execution The unit 1101 reads real-time data corresponding to the physical links PL1 to PLm from the storage device (step S2002). Then, the second execution unit 1103 controls the transmission unit 1102 to transmit the read real-time data using the physical links PL1 to PLm (step S2003).
In this specification, the real-time data and the non-real-time data are distinguished by the difference in the destination address, but the present invention is not limited to this. Specifically, for example, information indicating any communication may be added as header information of real time data and non-real time data.
As described above, according to the disclosed technology, it is possible to transfer non-real time data between groups using the virtual link VL that connects between the relay nodes JN selected from each group. Thereby, the non-real time data between groups can be put together and the collision with real time communication can be reduced.
Further, according to the disclosed technology, it is possible to transfer non-real time data between groups at a time different from the cycle start time of the real time communication periodically executed in the network 210. Thereby, the implementation period of real-time communication and non-real-time communication can be distinguished, and the collision with real-time communication and non-real-time communication can be avoided.
Further, according to the disclosed technology, the network system 200 can be constructed using a plurality of switch devices, so that the flexibility and expandability of the system configuration can be improved.
Further, according to the disclosed technology, it is possible to calculate the data flow rate allocated to the virtual link VL based on the transmission capability of the network 210. Thereby, the data flow rate of non-real-time communication can be controlled according to the capacity of the physical link of the network 210.
Further, according to the present disclosure technique, it is possible to calculate the data flow rate allocated to the virtual link VL based on the non-real time data transferred from the relay node JN of another group. Thereby, the data flow rate of non-real-time communication can be controlled according to the actual communication status between groups.
Further, according to the disclosed technique, real-time communication can be performed using the destination address of the node N that is uniquely determined in the entire network system 200. Further, according to the disclosed technology, it is possible to execute non-real-time communication using the destination address of the node N that is uniquely determined in each group. Thereby, in the network system 200, real time data and non-real time data can be distinguished.
Further, in the communication method described above, there is a topology restriction that a switch device that is not directly connected to the relay node JN cannot be connected adjacently. Specifically, for example, when a switch device that connects switch devices such as a core switch and a router switch is installed, a switch device that is not directly connected to the relay node JN is connected adjacently. In this case, data collides between switch devices that are not directly connected to the relay node JN, resulting in the same problem as in the prior art.
Therefore, the relay node JN is installed in the switch device that connects the switch devices. Specifically, the relay node JN is installed in the switch device that connects the switch device directly connected to the relay node JN and the switch device not directly connected to the relay node JN.
FIG. 21 is a system configuration diagram (part 2) of the network system according to the embodiment. In the network system 2100, small groups SG1 to SG15 formed by a node group (not shown) directly connected to the individual switch devices SW1 to SW16 are communicably connected via the network 210.
The large group BG1 is formed by the small groups SG1 to SG5, the large group BG2 is formed by the small groups SG6 to SG10, and the large group BG3 is formed by the small groups SG11 to SG15. Here, the switch devices SW5, SW10, and SW15 are core switches that connect the switch devices. Therefore, relay nodes 2110, 2120, and 2130 are installed in the switch devices SW5, SW10, and SW15.
In the network system 2100, non-real time communication exceeding the large groups BG1 to BG3 is performed by transmitting non-real time data to a large group relay node (for example, the relay nodes 2110, 2120, 2130) once as communication between small groups. To do. Further, for communication between large groups, non-real time communication can be executed without interfering with real time communication by performing the same communication processing procedure as that between relay nodes between small groups.
In this way, it is possible to cope with a large-scale system by preventing adjacent switch devices that do not have a direct relay node.
The communication method described in this embodiment can be realized by executing a program prepared in advance on a computer such as a personal computer or a workstation. The communication program is recorded on a computer-readable recording medium such as a hard disk, a flexible disk, a CD-ROM, an MO, and a DVD, and is executed by being read from the recording medium by the computer. The communication program may be distributed via a network such as the Internet.
200, 2100 Network system 210 Network 501 Setting unit 502, 1104 Reception unit 503 Association unit 504 Transfer unit 505 Detection unit 506, 1105 Calculation unit 507, 1106 Allocation unit 508, 1102 Transmission unit 1101 First execution unit 1103 Second execution Part N Node JN Relay Node SN Normal Node
A first relay device directly connected to a first node group in the network that performs real-time communication and non-real-time communication between the nodes, and a second relay device connected to the first relay device in the network. Sets a route from the self-node selected from the first node group to the other node selected from the second node group via a second relay device directly connected to the node group A setting process to
A receiving step of receiving data relating to non-real-time communication from the remaining nodes other than the own node in the first node group to the remaining nodes other than the other node in the second node group;
A transfer step of transferring the data received by the reception step from the own node to the other node using the path set by the setting step;
Is executed by the computer of the node itself.
Causing the computer to execute a detection step of detecting a periodic start time of real-time communication periodically executed in the network;
The transfer step includes
Data related to the non-real time communication is transferred from the own node to the other node using a path set by the setting step at a time different from the cycle start time of the real time communication detected by the detecting step. communication program according to claim 1, characterized in that.
Based on the transmission capabilities of the previous SL network, a calculating step of calculating a data flow rate to be assigned to the set route,
Dividing the data flow calculated by the previous SL calculating step to the path and those Teru allocating step,
A transmission step of transmitting the allocation result allocated by the previous SL allocating step to the other node,
A communication program according to claim 1 or 2, characterized by causing the computer to perform.
The calculation step includes
4. The communication program according to claim 3, wherein a data flow rate to be assigned to a set path is calculated based on a data flow rate of non-real time data transferred from the other node to the own node.
Data relating to non-real time communication to the remaining nodes except the own node of the previous SL second node the first node group from the remaining nodes except the other nodes of the group, set by the setting step A non-real-time data receiving step for receiving from the other node using a path ;
And non-real-time data transfer step of transferring the data received by the pre-Symbol non-real time data reception step to the remaining nodes except the own node of the first node group,
An address that uniquely identifies a node included in the network is set in data related to real-time communication, and an address that uniquely specifies a node included in each node group is set in data related to non-real-time communication. The communication program according to any one of claims 1 to 5, wherein:
A first relay device directly connected to a first node group in the network that performs real-time communication and non-real-time communication between the nodes, and a second relay device connected to the first relay device in the network. Sets a route from the self-node selected from the first node group to the other node selected from the second node group via a second relay device directly connected to the node group Setting means to
Receiving means for receiving data relating to non-real-time communication from a remaining node excluding the own node in the first node group to a remaining node excluding the other node in the second node group;
Transfer means for transferring the data received by the receiving means to the other node using a path set by the setting means;
A relay node comprising:
Is executed by the computer of the self-node.
JP2009063492A 2009-03-16 2009-03-16 Communication program, relay node, and communication method Active JP5381194B2 (en)
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US12/723,751 US9049048B2 (en) 2009-03-16 2010-03-15 Recording medium having communication program recorded therein, relay node and communication method
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