JP2011082618A - Transmission-speed setting method and network hub device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission-speed setting method, capable of setting a transmission speed suitable to a hierarchical structure of a network, without limiting the degree of freedom of a network configuration, and to provide a network hub device to which the same is applied. <P>SOLUTION: In a process in which a predetermined control frame is transmitted to each network hub device, directly or indirectly connected to a port from the port of a network hub device included in the highest-order hierarchy of a network of a hierarchical structure including a plurality of hierarchies, and a network hub device of each hierarchy relays the control frame to own subordinate hierarchy, the network hub device of each hierarchy identifies a port from which the control frame is received as a port for a higher order connected to a network hub device of a higher order, and sets a transmission speed of each port other than the port for a higher order provided in its own device to a speed that does not exceed the transmission speed of the port for a higher order. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a transmission rate setting method for setting a transmission rate by auto-negotiation in a local area network or the like, and a network hub device having an auto-negotiation function.

  In a small to medium-sized network such as a local area network, a star type or tree type network configuration is often adopted.

  In a star-type or tree-type network configuration, it is desirable to set the transmission speed of a port connected to a higher-level network device higher than the transmission speed of a port connected to a lower-level network device.

  Conventionally, network administrators have optimized transmission rates for network devices in each layer by setting appropriate transmission rates for each port according to the position that each network device occupies in the network configuration. .

  In addition, the highest-level network device collects information on the transmission speed that each network device conforms to from each level of network device, and sets an appropriate transmission rate for each network device based on the collected information. Technology has also been proposed (see Patent Document 1).

  On the other hand, network devices that reduce the price by minimizing the functions to be installed are also commercially available. In such network devices, only automatic setting by auto-negotiation may be provided as a method for setting the transmission speed of each port.

JP 2004-104794 A

  By the way, in recent years, a general user often purchases commercially available network devices and uses an automatic setting function implemented in the network devices to construct a small network in the office. Such a small-scale network administrator does not necessarily have sufficient knowledge about the performance of individual network devices and the appropriate transmission rate to be set for each device. For this reason, when a new network device is added in the lower layer of the network, a higher transmission speed is set for the port connected to the added network device than to the port connected to the network device in the upper layer of the network. There was a case where it was done. Thus, if a commercially available network device is simply connected and the speed setting is left to auto-negotiation, it may not be possible to set a transmission speed suitable for the hierarchical structure of the network.

  On the other hand, in the technique in which the highest-level network device sets the transmission speed of the lower-level network device from the top-down, the highest-level network device has the function of collecting information on the lower-level network device and the setting of the lower-level network device. Additional control functions are provided. Therefore, the degree of freedom in the network configuration is limited, for example, a network device that does not have the additional function described above cannot be placed at the top.

  An object of the present disclosure is to provide a transmission rate setting method capable of setting a transmission rate suitable for a hierarchical structure of a network without limiting the degree of freedom of the network configuration, and a network hub device to which the transmission rate setting method is applied. .

  The above-described object can be achieved by the transmission rate setting method disclosed below.

  A transmission rate setting method according to one aspect is provided from a port of a network hub device included in the highest layer of a hierarchical network including a plurality of layers to each network hub device connected directly or indirectly to this port. In the process of transmitting a predetermined control frame and the network hub device of each layer relaying the control frame to each lower layer, the network hub device of each layer sets the port that received the control frame to the upper network hub. The port is identified as an upper port connected to the apparatus, and the transmission speed of each port other than the upper port provided in the own apparatus is set to a speed not exceeding the transmission speed of the upper port.

  The above-described object can be achieved by the network hub device disclosed below.

  A network hub device according to one aspect is a network hub device included in a hierarchical network including a plurality of layers, and includes a plurality of ports each capable of setting a transmission speed and one of the plurality of ports. When receiving a predetermined control frame, the port that received the control frame is identified as an upper port connected to the network hub device in the upper layer, and port information holding that maintains the transmission rate set for the upper port Control the transmission rate setting for the lower port so that the transmission speed of the lower port other than the upper port is equal to or lower than the transmission rate held in the upper port information holding unit. A network hub device in the lower hierarchy that sends the setting control unit and the control frame via each lower port And a frame relay section for relaying.

  According to the transmission rate setting method and the network hub apparatus described above, it is possible to set a transmission rate suitable for the hierarchical structure of the network without limiting the degree of freedom of the network configuration.

It is a figure which shows one Embodiment of the transmission rate setting method. It is a figure which shows one Embodiment of a network hub apparatus. It is a figure which shows another embodiment of a network hub apparatus. It is a figure which shows the example of a port information table. It is a flowchart showing the operation | movement according to reception of a control frame. It is a figure which shows another embodiment of a network hub apparatus. It is a flowchart showing operation | movement of a flame | frame transmission part. It is a figure which shows embodiment of the transmission rate setting method applied to virtual LAN. It is a figure which shows another embodiment of a network hub apparatus. It is a figure which shows the example of a port information table. It is a flowchart showing operation | movement of a network hub apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a transmission rate setting method.

  In the network shown in FIG. 1, the network hub device of the middle layer 1 is connected to one of the ports provided in the network hub device of the highest hierarchy connected to the server device. At least one network hub device included in the intermediate layer 2 is connected to at least one port of the network hub device. In addition, at least one network hub device in the lowest hierarchy is connected to at least one port provided in each of these network hub devices included in the intermediate layer 2. A terminal and a printer are connected to each port provided in each network hub device in the lowest hierarchy.

With such a connection, a tree-structured network is formed that branches according to the number of ports of each network hub device included in each layer.
In such a network, a method for automatically setting the transmission speed of the ports provided in the network hub devices of each hierarchy in consideration of the position occupied by each network hub device in the network structure will be described.

  First, when each network hub device receives a predetermined control frame transmitted from the network hub device at the highest layer, it identifies the port that has received this control frame as an upper port connected to the upper layer. To do. Each network hub device identifies each port other than the upper port as a lower port, and sets a transmission rate that does not exceed the transmission rate of the upper port to these lower ports. Thereafter, each network hub device relays the control frame described above to the lower layer via these lower ports.

  In this way, in the process of relaying the above-described control frame according to the tree structure, in the network hub device of each layer, the upper port is identified as described above, and the transmission speed of the lower port is higher. Limited to the transmission speed of the target port.

  Thereby, the transmission rate of the port of each network hub device can be automatically set so that the transmission rate on the backbone side of the network is higher than the transmission rate on the peripheral side. Therefore, even when a new network device is added to the lower layer of the network, the transmission speed of each port of the network device can be limited so as not to exceed the transmission speed of the port connected to the upper layer. . This prevents the occurrence of a transmission rate reversal such that the transmission speed of the port connected to the lower layer network device is set higher than that of the port connected to the upper layer network device. Can be prevented.

  As the predetermined control frame, for example, a control frame in which an identification code indicating that it is a control frame for automatic setting of a transmission rate is set in LLC (Local Link Control) arranged at the head of the data portion. Can be used.

  Here, in the transmission rate setting method shown in FIG. 1, the transmission rate of each port is set autonomously by each network hub device. Therefore, when this transmission rate setting method is applied, it is necessary to provide a specific network device with a function of collecting information on the transmission rate of the entire network or setting the transmission rate of all ports in a top-down manner. Absent. That is, according to this transmission rate setting method, it is possible to set a transmission rate suitable for the hierarchical structure of the network while maintaining the degree of freedom of the network configuration.

  Such a transmission rate setting method can be realized by providing a network hub device as described below in each layer.

  FIG. 2 shows an embodiment of a network hub device.

  The network hub device 210 illustrated in FIG. 2 includes n ports P1 to Pn, a frame relay unit 211, a port information holding unit 212, and a setting control unit 213.

  In the example shown in FIG. 2, the port P1 is connected to an upper layer network hub device (not shown), and the ports P2 to Pn are connected to a lower layer network hub device (not shown). . That is, in the example shown in FIG. 2, the port P1 is an upper port connected to the upper layer, and the ports P2 to Pn are lower ports connected to the lower layer. In these ports, when the opposite network hub device is connected, the highest transmission rate applicable to each opposite destination is set by auto-negotiation.

  When a predetermined control frame is received, the port information holding unit 212 holds information indicating the transmission rate already set for the port that has received this control frame. Further, the port that has received the control frame described above is identified as an upper port, and the identifier (for example, P1) of this port is held as information indicating the upper port.

  In addition, the setting control unit 213 sets the transmission rate of these ports to the higher level for each port (for example, ports P2 to Pn) other than the higher level port indicated by the port identifier held in the port information holding unit 212. Control the setting so that it is less than the transmission speed of the port. For example, when the transmission rate already set for each port other than the higher-order ports (for example, ports P2 to Pn) is higher than the transmission rate of the higher-order port, the setting control unit 213 The setting can be changed up to the upper limit.

  In this way, in response to reception of the control frame, the transmission rate applied to the other lower ports is changed up to the upper limit of the transmission rate set in the upper port that received this control frame, It can be controlled so that it is less than the transmission speed of the port.

  After that, the frame relay unit 211 sends the control frame described above via each lower port, relays it to the lower layer network hub device, and uses it for the transmission rate setting process in the relay destination network hub device.

  As described above, in the network hub device shown in FIG. 2, in the process of relaying the predetermined control frame described above to the lower layer, the transmission rate of each lower port is transmitted to the upper port by the setting control unit 213. It is set not to exceed the speed. Then, such a transmission rate setting process is executed in the network hub device of each layer of the network in the process of relaying the above-described control frame from the highest layer to the lowest layer of the tree-structured network. The Thereby, the transmission rate of the port of each network hub device can be automatically set so that the transmission rate on the backbone side of the network is higher than the transmission rate on the peripheral side.

Next, another embodiment of the network hub device will be described.
(Embodiment 1)
FIG. 3 shows another embodiment of the network hub device. Note that among the components shown in FIG. 3, the same components as those shown in FIG. 2 are denoted by the same reference numerals, and description thereof is omitted.

  The network device control unit 214 illustrated in FIG. 3 controls communication with network devices connected via the ports P1 to Pn. The frame control unit 215 controls relaying and transmission for a predetermined control frame for the transmission rate setting process described above.

  The relay control unit 216 provided in the frame control unit 215 monitors communication control processing by the network device control unit 214, detects reception of the predetermined control frame described above, and displays information indicating the received port as a port information holding unit 212 to be held. Also, the relay control unit 216 relays the above-described control frame to a lower layer via the network device control unit 214. In the network hub device shown in FIG. 3, the relay control unit 216 and the network device control unit 214 perform the same function as the frame relay unit 211.

  A frame transmission unit 217 provided in the frame control unit 215 generates a predetermined control frame for setting a transmission rate, and transmits this control frame. Details of the operation of the frame transmission unit 217 will be described later.

  The port information holding unit 212 illustrated in FIG. 3 includes a port information table 221. The port information table 221 indicates, for example, directivity information indicating whether the port is connected to an upper layer or a lower layer and the transmission rate set for the port, corresponding to the identifier of each port. Holds speed information and port status information.

  FIG. 4 shows an example of the port information table. In the example shown in FIG. 4A, “UP” indicating a link-up state communicable with the opposite destination or “DOWN” indicating a link-down state is stored as the port state information. Further, in the example shown in FIG. 4A, the directivity information indicating that it is connected to the upper layer is indicated as “upward”, and the directivity information indicating that it is connected to the lower layer is indicated as “lower”. Indicated. The directivity information, speed information, and status information corresponding to each port are collected from each port when the reception of the control frame is detected and information indicating the received port is passed to the port information holding unit 212. And stored in the port information table 221.

  In the setting control unit 213 illustrated in FIG. 3, the speed comparison unit 218 compares the speed information held in the port information table 221 and detects a port for which a higher transmission speed is set than the upper port. Further, the speed setting unit 219 changes the transmission speed setting for each port detected by the speed comparison unit 218.

  The operation of controlling the transmission rate of each port in response to reception of the control frame in the network hub device shown in FIG. 3 will be described below.

  FIG. 5 is a flowchart showing an operation according to reception of a control frame.

  When the control frame for setting the transmission rate is received via any of the ports provided in the network hub device, the relay control unit 216 identifies the port that has received the control frame (step 301). The relay control unit 216 refers to, for example, the data part of the received signal processed by the network device control unit 214, and determines whether or not an identification code indicating that the control frame is used for setting the transmission rate is set in the LLC. The control frame described above can be discriminated.

  For example, as shown in FIG. 3, when the control frame described above is input to the port P1 connected to the upper layer, the relay control unit 216 identifies the port P1 as the port that received the control frame. The At this time, the relay control unit 216 sets the directivity information indicating that the control frame reception port (for example, port P1) is an upper port in the port information table 221 and indicates that the other ports are lower ports. Set the directional information. Further, speed information indicating the transmission speed set for each port and port status information are also set in the port information table 221 (step 302).

  In this way, by specifying the port to which the control frame having a predetermined format for setting the transmission rate is input, the port for the higher level connected to the network hub device of the higher layer among the plurality of ports Can be reliably identified. In the network hub device 210 shown in FIG. 3, the relay control unit 216 performs the process of step 302 described above, thereby fulfilling the function of the table management unit.

  Next, a process in which the setting control unit 213 optimizes the transmission rate setting for each port based on the directivity information and the speed information set in the port information table 221 as described above will be described.

  First, the speed comparison unit 218 shown in FIG. 3 refers to the port information table 221 and acquires the speed information held corresponding to the port indicated by the directivity information as the upper port (step 303). Next, the speed comparison unit 218 includes a transmission speed indicated by the speed information held corresponding to each port indicated by the directivity information as a lower port and a transmission speed indicated by the speed information of the upper port. Are sequentially compared (step 304).

  When the speed comparison unit 218 detects a low-order port set with a transmission speed that is not less than or equal to the transmission speed set for the high-order port (negative determination in step 305), the speed setting unit 219 detects The speed setting of the lower port is changed (step 306).

  At this time, for example, the speed setting unit 219 receives, from the speed comparison unit 218, the detected lower port identifier and the transmission speed set for the upper port, and transmits the received transmission speed to the port specified by this identifier. Execute the setting process. For example, the speed setting unit 219 can change the transmission speed setting of the port by limiting the synchronization signal used by the setting target port during auto-negotiation. That is, the speed setting unit 219 instructs the port to be speed set to selectively use a synchronization signal corresponding to a transmission speed equal to or lower than the transmission speed of the above-described upper port in the auto negotiation. Such transmission rate setting processing can also be performed via the network device control unit 214. Then, the speed setting change for each lower-order port performed as described above is reflected in the port information table 221 by the speed setting unit 219.

  On the other hand, if the determination in step 305 is affirmative, step 306 is skipped. In this way, it is possible to selectively change the transmission rate for the lower port, which has a transmission rate that exceeds the transmission rate set for the upper port, to limit the transmission rate to the transmission rate of the upper port. it can.

  Thereafter, in step 307, the speed comparison unit 218 determines whether or not the comparison with the speed set for the upper port is completed for all the lower ports, and returns to step 304 if the determination is negative. Then, the next lower port is processed.

  In this way, the processing of step 304 to step 307 is repeated for each lower port, and when the processing for all lower ports is completed (Yes determination in step 307), the processing proceeds to step 308.

  For example, when the relay controller 216 receives a notification from the speed comparator 218 that processing for all lower ports has been completed, the relay controller 216 uses the function of the network device controller 214 to transmit the control frame described above. Relay to lower layer (step 308). For example, the relay control unit 216 relays the control frame to the lower level network hub device by instructing the network device control unit 214 to transmit the control frame described above via each lower port. Can do.

  Then, in the lower layer network hub apparatus that has received the control frame relayed in this way, similarly, the upper port and the lower port are discriminated, and the transmission speed of the lower port is set to the upper port. It is adjusted below the transmission speed of Then, the above-described control frame is relayed from this relay destination network hub device to a lower layer network hub device. Then, in the process of relaying the control frame for setting the transmission rate described above, the transmission rate of the port provided in the network hub device of each layer is the transmission rate set to each port of the network hub device of the upper layer. The speed is adjusted to the upper limit. As described above, the network hub apparatus 210 as shown in FIG. 3 optimizes the transmission speed of the port of the network hub apparatus belonging to each layer by performing the above-described processing independently in response to reception of the control frame. can do. That is, the transmission speed of the port of the network hub device belonging to each layer can be adjusted so that the transmission speed on the backbone side of the network is higher than the transmission speed on the peripheral side.

  Note that the speed setting unit 219 can omit the above-described transmission speed setting change processing for the port indicated by the state information to be in the link-down state.

  For example, in the example shown in FIG. 4A, 100 Mbps is set as the transmission speed of the upper port (port P1), and 1 Gbps is set as the transmission speed of the ports P2 and Pn. In the port information table 221 shown in FIG. 4A, the state information indicates that the port P2 is in the link-up state, while the port Pn is in the link-down state.

  For example, the speed comparison unit 218 refers to the status information together with the speed information of each port, sets a transmission speed that exceeds the transmission speed of the upper port (for example, port P1), and is in a link-up state. Can be detected as a setting change target. In this way, for the port P2 indicated to be in the link-up state, the speed setting unit 219 performs processing for selectively changing the transmission speed to the same transmission speed as the upper port (for example, 100 Mbps). be able to. On the other hand, since it is indicated that the port Pn is in the link down state, the transmission rate setting is maintained as it is because it is not detected as a setting change target.

Next, an embodiment of a network hub device installed in the highest hierarchy will be described.
(Embodiment 2)
FIG. 6 shows another embodiment of the network hub device. 6 that are the same as those shown in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted.

  The port P1 of the network hub device 210 illustrated in FIG. 6 is connected to the server device 200. Also, network hub devices (not shown) belonging to different small networks can be connected to the other ports P2 to Pn. For example, when a small network as shown in FIG. 1 is connected to the port P2 of the uppermost network hub device 210 shown in FIG. 6, this port P2 is the base point (TOP port) of the small network described above. ).

  Further, the port information table 221 of the network hub device 210 shown in FIG. 6 stores the directional information “TOP” corresponding to the port serving as the base point of the small-scale network (FIG. 4B). reference). For example, when a user connects a small-scale network to the uppermost network hub device 210, the above-mentioned directivity information can be set in the port information table 221 corresponding to the port used for connection.

  Hereinafter, an operation in which the frame transmission unit 217 provided in the network hub device 210 transmits a control frame for setting a transmission rate based on the port information table 221 will be described.

  FIG. 7 is a flowchart showing the operation of the frame transmission unit.

  The frame transmission unit 217 refers to the port information table 221 (step 311), and determines whether there is a TOP port based on the directivity information (step 312). When a TOP port is detected (affirmative determination in step 312), a control frame transmission process to be described later is executed.

  First, the frame transmission unit 217 repeats Steps 313 and 314 for the TOP port searched in Step 311, and transmits a control frame for setting the transmission rate via all detected TOP ports.

  At this time, for example, as described above, the flake transmitting unit 217 can transmit a control frame in which a predetermined identification code is set in the LLC of the data unit without specifying the destination. Thereby, this control frame is delivered to all network devices included in the connected small network.

  Then, after transmitting the above-described control frame via all TOP ports, the frame transmission unit 217 repeats Step 315 until a predetermined time has elapsed. When a predetermined time has elapsed, as a positive determination in step 315, the process returns to step 311, and the TOP port is detected again with reference to the port information table 221.

  That is, the frame transmission unit 217 provided in the uppermost network hub device 210 repeats the process of transmitting the predetermined control frame described above from the TOP port at predetermined time intervals in the operating state. As a result, the control frame described above is input at a predetermined time interval to the small-scale network connected to this value and one of the TOP ports of the work hub device 210. Transmission rate setting processing is performed.

  In this way, by configuring the transmission of control frames at predetermined time intervals, the transmission rate setting is changed flexibly in response to a change in the configuration of a small-scale network after the start of operation. It becomes possible. As an example in which the configuration of the small-scale network is changed after the operation is started, for example, a case where a new network device is connected to the intermediate layers 1 and 2 shown in FIG. Even in such a case, when the transmission rate is set by auto-negotiation at the time of expansion, when the control frame is received, the port connected to the network device added based on the transmission rate of the host port The transmission speed is limited.

  On the other hand, when the TOP port is not set in the port information table 221 (No at Step 312), the processing of the frame transmission unit 217 is terminated. Note that in the case of a negative determination in step 312, the frame transmission unit 217 can skip steps 313 and 314 and proceed to step 315, and perform a process of searching for a TOP port again after a predetermined time has elapsed. Further, as a negative determination in step 312, the network hub device can be configured to perform an operation according to reception of the control frame shown in FIG. 5 after the processing of the frame transmission unit 217 is finished.

Next, a method for optimizing the transmission rate in each virtual LAN when a single network hub device is physically divided and belongs to a plurality of virtual LANs will be described.
(Embodiment 3)
FIG. 8 shows an embodiment of a transmission rate setting method applied to a virtual LAN. FIG. 9 shows another embodiment of the network hub device. 9 that are the same as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

The port P1 and the port P2 of the network hub device HUB0 in the highest hierarchy shown in FIG. 8 are the TOP ports of the virtual LANV10 and the virtual LANV20, respectively. Further, the virtual LANV 10 includes the lowest-layer network hub devices HUB2 _{2 to} HUB2 _m connected to the ports P2 to Pm of the intermediate-layer network hub device HUB1. The port P1 of the network hub device HUB1 described above is connected to the port P1 of the network hub device HUB0 in the highest hierarchy. On the other hand, the virtual LANV 20 includes the lowermost network hub devices HUB2 _{m + 1 to} HUB2 _n-1 connected to the ports Pm + 1 to Pn-1 of the above-described intermediate layer network hub device HUB1. The port Pn of the network hub device HUB1 is connected to the port P2 of the highest level network hub device HUB0.

  In the example shown in FIG. 8, the network hub device HUB1 in the middle layer is physically included in both of the two virtual LANs V10 and V20, though it is a single device. For example, the identifier of the virtual LAN that includes the port is stored in the port information table 221 provided in the network hub device 210 shown in FIG. 9 as part of the state information corresponding to each port. Can be shown by doing.

  FIG. 10 shows an example of the port information table. In the example shown in FIG. 10A, a VLAN identifier V10 indicating that it belongs to the virtual LAN V10 is stored as state information corresponding to the ports P1 to Pm. Further, a VLAN identifier V20 indicating that it belongs to the virtual LAN V20 is stored as state information corresponding to the ports Pm + 1 to Pn.

  Hereinafter, the operation when the transmission speed is set independently for each virtual LAN will be described.

  FIG. 11 is a flowchart showing the operation of the network hub device. Of the steps shown in FIG. 11, the same steps as those shown in FIG. 7 are denoted by the same reference numerals.

  In the flowchart shown in FIG. 11, first, the frame transmission unit 217 detects a TOP port based on the port information table 221 (steps 311 and 312). If a TOP port is detected (Yes in Step 312), a process for transmitting a control frame for setting a transmission rate is performed in the same manner as in Steps 313 to 315 shown in FIG. 7 (Step 312). 321), the process of returning to step 311 is repeated.

  On the other hand, when the TOP port is not detected (No at Step 312), the process for setting the transmission rate in response to the reception of the control frame and the process for relaying the control frame to the lower layer as described later Is done.

  The relay control unit 216 repeats step 322 and waits for input of a control frame. When the control frame is detected (Yes in step 322), the relay control unit 216 identifies the port that has received the control frame, and sets the directivity information indicating that the port is an upper port (step 322). 323). Also, the relay control unit 216 refers to the port information table 221 and acquires port information held corresponding to the port in which the directivity information indicating that the port is a higher port is set in response to reception of the control frame. (Step 324). Then, based on the acquired port information, the relay control unit 216 extracts a target port that is a target of the above-described process of relaying the control frame to a lower layer and a transmission rate setting process (step 325).

  For example, the relay control unit 216 includes a port in which the same virtual LAN identifier as the state information acquired for the above-described upper port is included in the state information held in the port information table 221 corresponding to each port. It can be extracted as a target port. For example, when a control frame is received via the port P1 belonging to the virtual LAN V10, the relay control unit 216 extracts ports P2 to Pm as target ports based on the port information table shown in FIG. be able to. Then, the relay control unit 216 sets directivity information indicating that the port is a lower port in the port information table 221 corresponding to the target port extracted in this way (step 326).

  Next, the target port extracted as described above is subjected to processing for setting the transmission rate of each port to be equal to or lower than the transmission rate of the higher-order port in the same manner as Step 304 to Step 308 shown in FIG. For example, the speed comparison unit 218 illustrated in FIG. 9 sequentially compares the transmission speed held in the port information table 221 corresponding to the ports P2 to Pm with the transmission speed of the upper port P1 (step 327). When the speed comparison unit 218 detects a port (for example, P2) in which a transmission rate higher than the transmission rate of the higher-order port is detected (No determination in step 328), the speed setting unit 219 A process for changing the transmission speed is performed for the port (step 329). At this time, the port transmission speed setting changed by the speed setting unit 219 is also reflected in the port information table 221.

  The processing from step 327 to step 330 is repeated for each extracted target port. Then, when the processing for all the target ports is completed (Yes determination at step 330), the relay control unit 216 transmits the above-described control frame via each target port (step 331).

  Thereafter, the processing of the network hub device 210 returns to step 311. Then, in response to the reception of the control frame to the port Pn (affirmative determination in step 322), step 323 is performed for the ports Pm + 1 to Pn−1 connected to the network hub devices belonging to the lowest layer of the virtual LAN V20. Processing of ~ step 331 is performed. By this series of processing, processing for optimizing the transmission speed of these ports Pm + 1 to Pn−1 and processing for relaying the control frame to the network hub device connected through these ports are performed.

  In this way, in the network system as shown in FIG. 8, in the process of transmitting the above-described control frame independently to each network hub device belonging to each virtual LAN, the transmission speed of the ports provided in each network hub device is increased. Can be optimized.

  Note that the network hub device 210 shown in FIG. 9 can be arranged not only in the intermediate layer but also in the highest hierarchy or the lowest hierarchy. When arranged in the highest hierarchy, the network hub device 210 repeats Steps 311, 312 and Step 321 in the flowchart shown in FIG. 11 and transmits a control frame from the TOP port at predetermined time intervals. On the other hand, when arranged in the lowest hierarchy, the network hub device 210 performs a process of optimizing the transmission rate of each port in the same manner as the above-described intermediate layer network hub device.

  In other words, by using the network hub device 210 configured as shown in FIG. 9, it is possible to share the specifications of the network devices constituting the small and medium-sized network. Sharing the specifications of network devices such as a network hub device can greatly improve the degree of freedom of network configuration. By using network devices that are commonly used, it is possible to simplify the work for a user to construct a network, and to make it easier to manage additions and transfers.

  When the network hub device 210 is arranged in the lowest layer, the process of relaying the control frame (step 331 in FIG. 11) can be omitted.

  In addition, for example, the above-described transmission speed optimization processing is performed on a port connected to a device that communicates only within a single virtual LAN, such as a port connected to a printer shared within the virtual LAN. It can be removed from the target.

  For example, as shown in FIG. 10B, corresponding to the port Pn-1 connected to the printer shared in the virtual LAN, the directional information “out” is stored in the port information table 221 in advance, Indicates that this port is excluded from the determination for the upper level or the lower level. In this case, whether or not the directional information “out” is included in the port information can be used as exclusion information. Then, in step 325 shown in FIG. 11, when the relay control unit 216 extracts the target port, the setting by the speed setting unit 219 is performed by excluding the port storing the directivity information “out” from the target port. This port can be removed from the target.

  In this case, the transmission rate set for the port (for example, Pn-1) for which the directional information “out” is set is set to auto regardless of the transmission rate of the upstream port corresponding to the network connected to this port. The transmission rate set in the negotiation is maintained.

  Note that the above-described directional information “out” can be stored in the port information table 221 by an operation by a user, for example. Further, the directivity information “out” is not rewritten by the processing of the relay control unit 216, similarly to the directivity information “TOP” indicating the port serving as the base point of the small-scale network. In addition, instead of setting the above-described directivity information “out” for the port to be excluded from the setting target, it is possible to add exclusion information indicating that the speed setting process excludes the port to the corresponding port information. You can also indicate excluded ports by.

Regarding the above description, the following items are further disclosed.
(Appendix 1) A predetermined control frame is transmitted from a port of a network hub device included in the highest layer of a hierarchical network including a plurality of layers to each network hub device connected directly or indirectly to this port. And
In the process in which the network hub device of each layer relays the control frame to the lower layer, the network hub device of each layer connects the port that received the control frame to the upper network hub device. As a higher port,
The network hub device of each layer sets the transmission rate of each port other than the upper port provided in the own device to a rate not exceeding the transmission rate of the upper port. .
(Appendix 2) A network hub device included in a hierarchical network including a plurality of layers,
Multiple ports with individually configurable transmission rates,
When a predetermined control frame is received via any of the plurality of ports, the port that has received the control frame is identified as an upper port connected to an upper layer network hub device, and the upper port A port information holding unit that holds the transmission rate set to
Controls the transmission rate setting for the lower port so that the transmission rate of the lower port other than the upper port is equal to or lower than the transmission rate held in the upper port information holding unit among the plurality of ports. A setting control unit to
A network hub device comprising: a frame relay unit that transmits the control frame via each of the lower ports and relays the control frame to a lower layer network hub device.
(Supplementary Note 3) When the network hub device is located at the highest level of the network having the hierarchical structure, among the plurality of ports provided in the network hub device, the designated port is connected to this port. The network hub device according to appendix 2, further comprising a frame transmission unit that transmits the predetermined control frame so as to be delivered to a network hub device connected directly or indirectly.
(Supplementary Note 4) The port information holding unit
A port information table for storing port information including directivity information indicating whether each of the plurality of ports is an upper port or a lower port;
In response to reception of the control frame, port information including directivity information indicating that the port that received the control frame is an upper port is stored in the port information table, and other ports are lower port. The network hub device according to appendix 2, further comprising: a table management unit that stores port information including directivity information in the port information table.
(Additional remark 5) The said setting control part restrict | limits the synchronous signal used when the said some port adjusts a transmission speed with the apparatus of a connection destination based on the transmission speed of the said port for higher ranks, and is transmitted. The network hub device according to appendix 2, wherein the speed setting is controlled.
(Supplementary Note 6) The port information stored in the port information table corresponding to the plurality of ports includes state information indicating a logical network to which the port belongs in addition to the directivity information.
In response to reception of the control frame, the table management unit displays port information including directivity information indicating that the port is a lower port corresponding to a port belonging to the same logical network as the received port. Stored in
The setting control unit controls transmission rate setting for a port in which directivity information indicating that the port is a low-order port is stored in the port information table in response to reception of the control frame,
The frame relay unit transmits the control frame via each port in which directivity information indicating that the port is a lower port is stored in the port information table in response to reception of the control frame. The network hub device described in 1.
(Supplementary Note 7) The port information stored in the port information table corresponding to each port includes exclusion information indicating whether or not to exclude the port from transmission rate setting by the setting control unit,
The network hub device according to appendix 4, wherein the setting control unit excludes a port whose exclusion information indicating that it is excluded from the transmission rate setting in the port information table is stored.

210 Network hub device 211 Frame relay unit 212 Port information holding unit 213 Setting control unit 214 Network device control unit 215 Frame control unit 216 Relay control unit 217 Frame transmission unit 218 Speed comparison unit 219 Speed setting unit 221 Port information table

Claims (5)

A predetermined control frame is transmitted from the port of the network hub device included in the highest layer of the hierarchical network including a plurality of layers to each network hub device connected directly or indirectly to the port,
In the process in which the network hub device of each layer relays the control frame to the lower layer, the network hub device of each layer connects the port that received the control frame to the upper network hub device. As a higher port,
The network hub device of each layer sets the transmission rate of each port other than the upper port provided in the own device to a rate not exceeding the transmission rate of the upper port. . A network hub device included in a hierarchical network including a plurality of layers,
Multiple ports with individually configurable transmission rates,
When a predetermined control frame is received via any of the plurality of ports, the port that has received the control frame is identified as an upper port connected to an upper layer network hub device, and the upper port A port information holding unit that holds the transmission rate set to
Controls the transmission rate setting for the lower port so that the transmission rate of the lower port other than the upper port is equal to or lower than the transmission rate held in the upper port information holding unit among the plurality of ports. A setting control unit to
A network hub device comprising: a frame relay unit that transmits the control frame via each of the lower ports and relays the control frame to a lower layer network hub device. The network hub device according to claim 2, wherein
When the network hub device is located at the highest level of the hierarchical network, the port is directly or indirectly connected to this port through a designated highest port among a plurality of ports provided in the network hub device. A network hub device comprising: a frame transmission unit that transmits the predetermined control frame so as to be delivered to a network hub device connected to the network hub. The network hub device according to claim 2, wherein
The port information holding unit
A port information table for storing port information including directivity information indicating whether each of the plurality of ports is an upper port or a lower port;
In response to reception of the control frame, port information including directivity information indicating that the port that received the control frame is an upper port is stored in the port information table, and other ports are lower port. A network hub device comprising: a table management unit that stores port information including directivity information in the port information table. The network hub device according to claim 4, wherein
Port information stored in the port information table corresponding to the plurality of ports includes state information indicating a logical network to which the port belongs, in addition to the directional information,
In response to reception of the control frame, the table management unit displays port information including directivity information indicating that the port is a lower port corresponding to a port belonging to the same logical network as the received port. Stored in
The setting control unit controls transmission rate setting for a port in which directivity information indicating that the port is a low-order port is stored in the port information table in response to reception of the control frame,
The frame relay unit transmits the control frame via each port in which directivity information indicating that the port is a lower port is stored in the port information table in response to reception of the control frame. apparatus.

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