Network relay apparatus

The present invention relates to a network relay device capable of switching to a power saving mode.

The usage mode in which a personal computer is always connected to the Internet and the operation mode in which a server machine operates 24 hours a day are increasing. Attempts have been made to reduce the power consumption of various electric appliances, but in such a constant use mode, it is possible to reduce the power consumption during standby when the computer or peripheral device is not in normal operation. It is needed.

Therefore, a function for switching the power saving mode has been incorporated into network relay devices such as hubs and routers, which have not been targeted for power saving until now. Patent Document 1 provides a mechanism for checking the presence or absence of a received signal of a multi-port relay device and turning off the power of the multi-port relay device when the terminal device of the other party connected to the relay device is inoperable. It is specified. Further, in Patent Document 2, in a network device having a plurality of ports, the presence / absence of a signal of each port is detected, and when there is no signal of all the ports for a specified time or more, the power of the network device is turned off. The mechanism to make it into a state is clearly stated.

Further, in Patent Document 3, in an electronic device including a transceiver and a physical layer (physical interface) that transmits / receives data to / from the transceiver, a signal is transmitted to the transceiver when the physical layer transitions to the power saving mode. A mechanism for power saving between the physical layer and the transceiver is disclosed by setting the transceiver in the power saving mode.<patcit num="1"><text>Japanese Unexamined Patent Publication No. 9-275411</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2002-32159</text></patcit><patcit num="3"><text>Japanese Patent Application Laid-Open No. 2002-118563</text></patcit>

<p> However, when the power of the network relay device is turned off as in Cited Document 1 and Cited Document 2, the physical interface included in the network relay device is naturally stopped. Normally, the physical interface includes a circuit that generates a link test pulse to confirm that the electronic devices physically connected to the network relay device are logically and correctly connected so that data communication is possible. , By stopping the physical interface in the power saving mode, it is automatically determined whether or not the relay device and the electronic device connected to the relay device are correctly connected without generating this link test pulse. It was difficult.</p><p> For example, when the network relay device is in the power saving mode, even if the LAN cable of the electronic device A connected to the network relay device is slightly disconnected from the electronic device A due to some vibration, it is in the power saving mode. It was impossible to detect the failure. When the network relay device returned from the power saving mode, it was finally possible to detect that the connection was not normal, but even in this case, it may be due to the effect of returning from the power saving mode, and the cause was early. It was difficult to identify.</p><p> Furthermore, since electronic device A confirms the connection of the LAN cable by the link test pulse, when the link test pulse is stopped, a cable disconnection error may be falsely reported or the lamp indicating the cable connection may turn off. there were.</p><p> Further, in Reference 3, in an electronic device including a transceiver and a physical layer that transmits / receives data to / from the transceiver, the physical layer transmits a tone signal to a destination electronic device connected via a network via the transceiver. There is a description to send. This checks whether the electronic device connected to the transceiver is in a standby state or a power-off state, and if the electronic device is in a standby state or a power-off state, the transceiver and the physical layer are placed in a power saving mode. It is for making.</p><p> Therefore, when the transceiver and the physical layer are in the power saving mode, the tone signal is not transmitted to the connected electronic device, and when the transition to the power saving mode is performed as in the cited document 1 or the cited document 2. , It has become impossible to automatically determine whether or not the electronic devices connected to the relay device are correctly connected so that data communication is possible.</p>

<p> In order to solve this problem, claim 1 and claim 2 of the present invention are a network relay device provided with a physical interface capable of switching to a power saving mode, and a link test included in the physical interface is provided. In addition to the pulse generation circuit, a circuit for generating a link test pulse in the power saving mode of the physical interface is separately provided as a link test pulse transmission unit.</p><p> Further, claim 3 and claim 4 of the present invention are a network relay device provided with a physical interface capable of switching to the power saving mode, in which the power transmission path into the physical interface is divided into two systems to achieve the power saving mode. At times, it is characterized in that power transmission to the link test pulse generation circuit included in the physical interface is maintained, and power transmission to other than the link test pulse generation circuit is stopped.</p>

<p> By using the present invention, whether or not the electronic devices connected to the network relay device are correctly connected so that data communication is possible even when the physical interface provided in the network relay device is shifted to the power saving mode. It has the effect of helping to make a judgment.</p>

Before explaining the embodiment of the hub provided with the present invention, the conventional configuration of a hub typical as a network relay device will be described. Figure 5 shows a conventional hub 1 with a power saving mode. Hub 1 has a LAN port 11 for connecting LAN cables from other electronic devices, a transformer 12 for removing high voltage and noise to protect the internal circuit of hub 1, and a physical interface with a switch controller. Interface 13, non-signal monitoring unit 14 that monitors whether a signal has been received for a certain period of time, analyzes the destination of the received signal, and requests that the signal be sent to the electronic device corresponding to the destination. It consists of a switch controller 15.

The physical interface 13 is also called a PHY (Physical Interface) and bidirectionally converts an analog signal handled by the 10BASE-T standard or 100BASE-TX standard and a digital signal handled by the switch controller 15 into a hub or router. It is a required interface.

In the 10BASE-T standard and 100BASE-TX standard, the data transmission / reception function of electronic devices sharing a network is stipulated to be activated by receiving a link test pulse from the other party. Therefore, if the link test pulse is not received for a certain period of time, the data transmission / reception function of the electronic device is stopped.

Figure 2 shows the outline of a general hub. The hub 1 shown in FIG. 2 includes a plurality of LAN ports 11, a console port 22, and a status display LED 23. A LAN cable is connected to LAN port 11.

Figure 3 shows the usage pattern of the console port 22. As shown in FIG. 3, the console port 22 connects the cable of the console terminal 31 to the console port 22, and the user of the hub 1 registers or changes the setting of the hub 1 from the console terminal 31. Used for.

Hub 1 can also have its own IP address, and as shown in Figure 4, a console terminal 31 connected via network 41 can TELNET to hub 1 to register hub 1 settings. Of course, it is possible to change it. Further, the status display LED 23 of the hub 1 shown in FIG. 2 is an LED for displaying the communication status.

&lt;First Embodiment&gt; Next, FIG. 1 shows the configuration of the network relay device according to the inventions of claims 1 and 2. The hub 2 shown in FIG. 1 has a configuration in which a link test pulse transmission unit 56, a jam signal transmission unit 57, and a preample detection unit 58 are added in addition to the configuration of the conventional hub 1 shown in FIG.

The link test pulse transmission unit 56 has a function of transmitting a link test pulse to an electronic device connected to the end of the LAN port 51 when the physical interface 53 of the hub 2 is in the power saving mode.

When the physical interface 53 of the hub 2 transitions from the power saving mode to the normal mode, the jam signal transmitting unit 57 sends a signal prompting the electronic device connected to the end of the LAN port 51 to retransmit the packet. It has the function of transmitting. Although the jam signal transmission unit 57 is described separately from the physical interface 53 in FIG. 5, it may be included in the physical interface 53.

The no-signal monitoring unit 54 has a function of checking whether or not the signal with the electronic device connected to the end of the LAN port 51 is in a no-signal state for a predetermined no-signal set time. As shown in FIG. 3, the user of the hub 2 connects the console terminal 31 to the console port 22 provided in the hub 2 and sets the no-signal setting time from the setting screen. It is also possible to set the no-signal setting time from the setting screen by connecting to the hub 2 by TELNET from the console terminal 31 sharing the network as shown in FIG. Figure 6 shows an example of the no-signal setting time setting screen displayed on the console terminal 31.

The preampl detector 58 detects the start signal of the frame transmitted from the electronic device connected to the end of the LAN port 51 when the physical interface 53 is in the power saving mode, and normally sets the physical interface 53 from the power saving mode. It has the function of transitioning to the mode. The preampl detection unit 58 does not detect the link test pulse.

Next, with reference to FIG. 7, the flow of processing in which the physical interface 53 transitions to the power saving mode and the flow of processing in which the physical interface 53 transitions from the power saving mode to the normal mode for each LAN port 51 will be described. It is assumed that the no-signal set time has been set for each port in advance.

Step S701 in FIG. 7 is a step in which the no-signal monitoring unit 54 resets its own no-signal timer. The next step S702 is a step in which the no-signal monitoring unit 54 activates the no-signal timer.

Step S703 is a step of determining whether the physical interface 53 has received a signal other than the link test pulse from the LAN port 51 or the switch controller 55. If the physical interface 53 has received a signal other than the link test pulse, step S701 If no signal other than the link test pulse is received, the process proceeds to step S704.

Step S704 is a step in which the no-signal monitoring unit 54 determines whether or not the time of the no-signal timer exceeds the preset no-signal set time. If the no-signal timer time exceeds the no-signal set time, the process proceeds to step S705, and if the no-signal timer time does not exceed the no-signal set time, the process proceeds to step S703. The no-signal setting time is preferably set to about 3 to 5 minutes.

Step S705 is a step in which the no-signal monitoring unit 54 shifts the physical interface 53 to the power saving mode. The power saving mode referred to here means to stop the power transmission to the physical interface 53, but the power transmission amount to the physical interface 53 may be reduced.

Step S706 is a step in which the link test pulse transmission unit 56 periodically transmits the link test pulse to the electronic device connected to the end of the LAN port 51. Specifically, it is desirable to send a link test pulse with a width of 80 to 130 ns at intervals of 8 to 24 ms according to a standard such as 10BASE-T or 100BASE-TX.

Step S707 is a step of determining whether or not the preamplifier detection unit 58 has received the preamplifier signal from the electronic device or switch controller 55 connected to the LAN port 51. If a pre-ample signal is received, the process proceeds to step S708, and if no pre-ample signal is received, the process returns to step S707.

Step S708 is a step in which the link test pulse transmission unit 56 stops the periodic transmission of the link test pulse to the electronic device connected to the LAN port 51.

Step S709 is a step in which the no-signal monitoring unit 54 shifts the physical interface 53 from the power saving mode to the normal mode. Here, it means that the power transmission to the physical interface 53 is restarted, but it may be possible to return the power transmission amount from the one that was smaller than the normal power transmission amount to the normal power transmission amount.

Step S710 is a step in which the jam signal transmitting unit 57 transmits a jam signal requesting retransmission of the packet to the electronic device connected to the end of the LAN port 51. As a result, it is possible to prevent the loss of the packet received immediately before the transition from the power saving mode to the normal mode.

The above is the flow of processing in which the physical interface 53 for each LAN port 51 transitions to the power saving mode and the flow of processing in which the physical interface 53 transitions from the power saving mode to the normal mode.

Although the embodiment to the hub has been described above, the invention of claim 1 is also applicable to a router, and FIG. 10 shows a configuration diagram when the invention is applied to a router.

As described above, in the first embodiment using the inventions of claims 1 and 2, a link test pulse is periodically applied to the electronic device connected to each port during the power saving mode of the physical interface in the network relay device. By transmitting to, the data transmission / reception function of the electronic device connected to each port can be kept active.

&lt;Second Embodiment&gt; Next, FIG. 8 shows the configuration of the network relay device according to the inventions of claims 3 and 4. In addition to the configuration of the conventional hub 1 shown in FIG. 5, the hub 8 shown in FIG. 8 has two power transmission paths to the physical interface 83, a power transmission path to the link test pulse transmission circuit 86, and a link test pulse transmission. It shall have a power transmission path to circuits other than circuit 86.

Next, with reference to FIG. 9, the flow of processing in which the physical interface 83 transitions to the power saving mode and the flow of processing in which the physical interface 83 transitions from the power saving mode to the normal mode for each LAN port 81 will be described. It is assumed that the no-signal set time has been set for each port in advance.

Steps S901 to S904 of FIG. 9 are the same processes as steps S701 to S704 of FIG. 7 in the first embodiment.

Step S905 is a step in which the no-signal monitoring unit 84 shifts the physical interface 83 to the power saving mode. The power saving mode referred to here means to stop power transmission to circuits other than the link test pulse transmission circuit 86 while maintaining power transmission to the link test pulse transmission circuit 86 in the physical interface 83. The amount of power transmitted to other than the link test pulse transmission circuit 86 may be reduced.

Step S906 is a step of determining whether or not the preamplifier detection unit 88 has received the preamplifier signal from the electronic device or switch controller 85 connected to the LAN port 81. If a pre-ample signal is received, the process proceeds to step S907, and if no pre-ample signal is received, the process returns to step S906.

Step 907 is a step in which the no-signal monitoring unit 84 shifts the physical interface 83 from the power saving mode to the normal mode. Here, it means to restart the power transmission to other than the link test pulse transmission circuit 86 in the physical interface 83, but even if the power transmission amount is returned from the one that was less than the normal power transmission amount to the normal power transmission amount. good.

Step S908 is a step in which the jam signal transmission unit 87 transmits a jam signal requesting retransmission of the packet to the electronic device connected to the end of the LAN port 81. As a result, it is possible to prevent the loss of the packet received immediately before the transition from the power saving mode to the normal mode.

Although not shown, this second embodiment can be applied to a router as in the first embodiment, and when applied to a router, the network corresponds to the switch controller 85. It becomes a processor, and the network processor has its own memory.

As described above, in the second embodiment using the inventions of claims 3 and 4, transmission to other than the link test pulse transmission circuit in the physical interface is stopped when the power saving mode of the physical interface in the network relay device is used. And keep the transmission of the link test pulse circuit. As a result, the link test pulse can be transmitted even in the power saving mode of the network relay device, and the data transmission / reception function of the electronic device connected to each port can be kept in the active state.

As described above, the network relay device of the present invention makes it possible to periodically transmit a link test pulse to the electronic device connected to each port even in the power saving mode of the physical interface in the network relay device. , The data transmission / reception function of the electronic device connected to each port can be kept active. This is useful for determining whether or not the electronic devices connected to the network relay device are correctly connected so that data communication is possible even when the physical interface of the network relay device is shifted to the power saving mode. effective.

The present invention can be used in a network relay device having a physical interface capable of switching to a power saving mode.

<figref num="1">The figure which showed the structure of the hub in 1st Embodiment.</figref><figref num="2">The figure which showed the outline of a general hub.</figref><figref num="3">The figure which showed an example which uses the console port of a hub.</figref><figref num="4">The figure which showed the example of setting the hub from the console terminal which shares a network.</figref><figref num="5">The figure which showed the structure of the conventional hub.</figref><figref num="6">The figure which showed the example of the setting screen of the no-signal time in 1st Embodiment.</figref><figref num="7">The flow chart which showed the flow of the process of power saving mode transition and normal mode return in 1st Embodiment.</figref><figref num="8">The figure which showed the structure of the hub in the 2nd Embodiment.</figref><figref num="9">The flow chart which showed the flow of the process of power saving mode transition and normal mode return in 2nd Embodiment.</figref><figref num="10">The figure which showed the configuration when the 1st Embodiment was applied to a router.</figref>

Code description

1, 2, 8 Hubs 10 Routers 11, 51, 81, 101 LAN Ports 12, 52, 82, 102 Transformers 13, 53, 83, 103 Physical Interfaces 14, 54, 84, 104 No Signal Monitor 15, 55, 85 Switch controller 22 Console port 23 Status display LED 31 Console terminal 41 Network 56, 106 Link test pulse transmitter 57, 87, 107 Jam signal transmitter 58, 88, 108 Preample detector 86 Link test pulse transmitter 105 Network processor 109 memory