JP2012105004A - Network concentrator and power control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network concentrator and power control method capable of achieving power saving in the event of power failure or the like with a simpler configuration than before.SOLUTION: In the event of power failure in a main power supply, a communication path 500 is set between a first and a second ports X-Y in a physical layer, supply of auxiliary power is received, and a supply destination of the auxiliary power is limited to the first port X and the second port Y, and a processing section 112 of the physical layer involved in the communication path 500.

Description

  The present invention relates to a network line concentrator and a power control method used for a communication network, for example.

  Examples of NW devices used in a communication network (NW) such as a WAN (Wide Area Network) and a LAN (Local Area Network) include a router, a switching hub, a wireless LAN access point, an IP (Internet Protocol) telephone, and a web camera. Etc. Among these NW devices, there is a device (hereinafter also referred to as “PoE device”) that supports a technology called PoE (Power over Ethernet) (“Ethernet” and “Ethernet” are registered trademarks).

  PoE is a technology for supplying power through a cable (category 5 or higher) used for Ethernet wiring, and is standardized as IEEE 802.3af and its extended version, IEEE 802.3at. In PoE, communication (data transmission) and power supply to an NW device can be performed with a single cable. Therefore, for example, the NW device can be installed in a place where it is difficult to supply power, or an external power source of the NW device can be made unnecessary. As a result, it is possible to reduce the NW line and reduce the cost. The PoE device on the power supply side is called PSE (Power Source Equipment), and the PoE device on the power receiving side is called PD (Powered Device).

  As a technique related to PoE, for example, there is a technique described in Patent Document 1 below. The patent document 1 describes that the power line of the port A of the PD is internally bypassed to another port B in the device. Accordingly, the port B functions as a power supply port, and a part of the power received by the port A can be supplied (relayed) to the Ethernet device connected to the power supply port B. Therefore, the power received at the port A can be effectively used by a plurality of Ethernet devices.

  On the other hand, when PoE connection is used, if power supply to a higher-level (uplink) NW device (for example, a LAN switch) that accommodates one or more NW devices stops due to a failure such as a power failure, the power is accommodated in the LAN switch. The power supply to the lower-level (downlink) NW device is also stopped. In preparation for such a failure, a backup power supply (auxiliary power supply) such as an uninterruptible power supply (UPS) may be connected to the upper NW device (see, for example, Non-Patent Document 1 below). . Non-Patent Document 1 describes that only an important IP telephone (communication line) among a plurality of IP telephones that are lower NW devices is accommodated in a LAN switch that is an upper NW apparatus connected to a backup power source. . This makes it possible to maintain important IP telephone communication during a power outage while reducing the number of backup power supplies installed.

  However, since the backup power source is intended to be temporarily used in the event of a power failure, the amount of power that can be used is limited. Therefore, power saving is required for the NW device when using the backup power source. As an example of such a power saving technique, Patent Document 2 below describes that only the operation of a port used for specific important communication such as an emergency call is maintained in an emergency such as a disaster, and other important communication is used. A router that shuts down the operation of unused ports is described. According to the router, since the power consumption of the auxiliary power supply can be reduced in the operation with the auxiliary power supply at the time of a power failure of the commercial power supply, the communication path for important communication can be maintained for a longer period than before. it can.

Special table 2008-539631 gazette JP 2008-167119 A

Kazuhito Aso, “Special feature of IP phone is dangerous” [online], June 1, 2007, Nikkei NETWORK, [October 20, 2010 search], Internet <URL: http: //itpro.nikkeibp. co.jp/article/COLUMN/20070525/272330/〉

However, in the prior art, there may be a case where the power saving of the NW device at the time of a power failure or the like is not sufficient.
For example, in the technique of Patent Document 1, the power line is bypassed between ports A and B, but the communication line is not bypassed and is connected to the “remainder of the circuit” (see the description of paragraphs 0050 and 0051, etc.). In order to maintain the existing communication path in the event of a power failure or the like, it is necessary to continue supplying power to all of the “remainder of the circuit” from a backup power source or the like.

  On the other hand, in the technology of Patent Document 2, important communication is performed by connecting ports (PHY) used for important communication via a switch (L2 / L3 switch) of an upper layer (layer 2 or layer 3) in the event of a power failure or the like. Is maintained (for example, see FIG. 9 of Patent Document 2). At this time, a part of the hardware resources of the L2 / L3 switch that are not involved in maintaining the important communication are shut down (set to disable communication) by setting whether or not communication can be performed for each port, but the entire L2 / L3 switch operates. The power for maintenance is still being supplied. Then, in general, the L2 / L3 switch has a very large power consumption compared to other hardware resources of the router, and therefore, the power supply to the L2 / L3 switch is maintained. It becomes a restriction in aiming at reduction.

  Therefore, for example, as shown in FIG. 10 of Patent Document 2, the ports (PHY) used for important communication are connected to each other via an ASIC provided separately from the L2 / L3 switch, thereby passing through the L2 / L3 switch. It is also possible to set a communication channel for important communication as a communication channel that does not. In this case, since the operation of the L2 / L3 switch may be stopped, the power supply to the L2 / L3 switch can be completely stopped. However, this requires an additional ASIC, which is disadvantageous in terms of circuit scale and cost.

  Accordingly, one of the objects of the present invention is to provide a network line concentrator and a power control method that achieve power saving in the event of a power failure or the like with a simpler configuration than before.

  In addition, the present invention is not limited to the above-described object, and other effects of the present invention can be achieved by the functions and effects derived from the respective configurations shown in the embodiments for carrying out the invention which will be described later. It can be positioned as one of

  One aspect of the network line concentrator of the present invention includes a first port to which a first network device is connected and capable of supplying power to the first network device, and a second port to which a second network device is connected. A physical layer processing unit that sets a communication path in the physical layer between the first and second ports at the time of a power failure of the main power supply; and a supply of auxiliary power at the time of the power failure; , The second port, and a power supply circuit limited to the physical layer processing unit.

  According to another aspect of the power control method of the present invention, a first network device is connected, a first port capable of supplying power to the first network device, and a second network device is connected to the second port. And a power control method for a network concentrator provided with a port, a process of setting a communication path in the physical layer between the first and second ports at the time of a power failure of a main power supply, and supply of auxiliary power at the time of the power failure The auxiliary power supply destination is limited to the first port, the second port, and a physical layer processing unit related to the communication path.

  Here, the supply source of the auxiliary power may be an auxiliary power supply outside or inside the network line concentrator, or may be the second port supplied with power through the second network device.

  The physical layer processing unit may relay a part of the auxiliary power to the first port during the power failure.

  The network concentrator may release the limitation on the power supply destination and the setting of the communication path when a power failure of the main power supply is restored.

1 is a diagram illustrating a network system including a network (NW) device according to an embodiment. FIG. 2 is a block diagram illustrating the configuration of the line switching apparatus illustrated in FIG. 1. 3 is a flowchart illustrating an operation (control method) of the line switching apparatus illustrated in FIGS. 1 and 2. It is a figure explaining the operation | movement (normal mode) of the line switching apparatus illustrated in FIG.1 and FIG.2. It is a figure explaining operation | movement (power saving operation mode) of the line switching apparatus illustrated in FIG.1 and FIG.2. It is a figure explaining the modification of operation | movement (power saving operation mode) of the line switching apparatus illustrated in FIG.1 and FIG.2.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. In other words, the present invention can be implemented with various modifications (combining the embodiments, etc.) without departing from the spirit of the present invention. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. The drawings are schematic and do not necessarily match actual dimensions and ratios. In some cases, the dimensional relationships and ratios may be different between the drawings.

  FIG. 1 is a diagram illustrating a network system including a network (NW) device according to an embodiment. The network system illustrated in FIG. 1 includes one or more network concentrators (hereinafter “concentrators” or “concentrators”) that enable connection of a plurality of communication devices 30 in a communication network (NW) 20 compliant with Ethernet such as WAN or LAN. Also referred to as “concentration switch”.

  An example of the line concentrator 10 is a switching hub, and examples of the communication device 30 are general-purpose computers, network printers, IP telephones, web cameras, switching hubs, and the like. These are all examples of network (NW) devices.

  The line concentrator 10 includes, for example, a plurality of ports, and the communication device 30 and other line concentrators 10 can be connected to any of the plurality of ports with an Ethernet cable. In the example shown in FIG. 1, the network 20 is connected to the upper (uplink) port of the concentrator 10-1, and the other concentrator 10-2 and two lower (downlink) ports of the concentrator 10-1. Each uplink port of one communication device 30 is connected. In addition, any of the uplink ports of up to n communication devices 30 is connected to any of n (n is an integer of 1 or more) downlink ports of the line concentrator 10-2.

  A backup power source (hereinafter also referred to as “auxiliary power source”) 40 such as a UPS can be connected to the line concentrator 10. When the power supply by the main power supply of the line concentrator 10 is stopped due to a failure such as a power failure, the line concentrator 10 can continue to operate by receiving power supply from the backup power supply 40. The backup power source 40 may be built in the line concentrator 10.

  Next, a configuration example of the line concentrator 10 will be described. FIG. 2 is a block diagram illustrating the configuration of the line concentrator 10 illustrated in FIG. The line concentrator 10 illustrated in FIG. 2 exemplarily includes a plurality of ports # 1 to #n (n is an integer of 1 or more), X and Y, a first physical layer processing unit (PHY unit) 111, a first 2 physical layer processing units (PHY units) 112, a switch unit 113, a control unit 114, and a power supply circuit 115.

  Port #i (any of i = 1 to n), port X, and port Y are all connectors such as RJ45, and can connect NW devices. Any of the plurality of ports may be a port with a PoE function. For example, the port X may be a downlink PoE port (power supply port) that can supply power to an NW device (for example, an IP phone) connected to the port X. Further, the port Y can be an uplink PoE port (power receiving port) that can receive power through an NW device (for example, another concentrator) connected to the port Y.

  The first PHY unit 111 illustratively accommodates n ports # 1 to #n and transmits / receives to / from the switch unit 113 through any port #i (any of i = 1 to n). The processed data signal is subjected to processing such as waveform shaping, amplification, and code conversion (hereinafter also simply referred to as “PHY processing”).

  The second PHY unit 112, for example, accommodates the port X and the port Y, and PHY regarding a data signal (in other words, communication between the ports XY) transmitted / received through any of the ports X and Y. Apply processing.

  Input / output of each of the PHY units 111 and 112 is connected to the switch unit 113, and the switch unit 113, according to the setting from the control unit 114, either the downlink port #i or the port X and the uplink port Y To communicate with each other. Thereby, a communication path for data communication via the switch unit 113 can be set between the ports.

  However, according to the setting from the control unit 114, the PHY unit 112 can internally set a communication path between the ports XY, that is, a communication path that does not pass through the switch unit 113, in the physical layer. For example, the PHY unit 112 has a transmission / reception buffer (not shown) capable of temporarily storing communication data transmitted / received through the ports X and Y for each of the ports X and Y. By changing the connection relationship according to the setting from the control unit 114, switching between a communication path that passes through the switch unit 113 and a communication path that does not pass through the switch unit 113 can be performed.

  The control unit 114 controls the operation of the entire line concentrator 10. Illustratively, the control unit 114 is connected to each control target unit including the PHY unit 111, the PHY unit 112, and the switch unit 113 through a control bus (not shown) so that they can communicate with each other. Can be controlled individually.

  The control unit 114 includes, for example, a CPU 141 and a memory 142. The memory 142 stores a control program executed by the CPU 141 and data (control code or the like) used for operation control of the line concentrator 10. The CPU 141 controls the operation of the line concentrator 10 by reading the control program and data stored in the memory 142 and executing the control program.

  The power supply circuit 115 supplies power to each part (resource) to be fed including the PHY units 111 and 112, the switch unit 113, and the control unit 114. The power supply source to the power supply circuit 115 is normally a predetermined power supply (main power supply) 116 such as a commercial power supply, and when the main power supply is abnormal such as a power failure, the auxiliary power supply 40 such as a UPS or a built-in battery, or uplink PoE power reception Port Y can be used. For example, the power supply circuit 115 includes a power supply monitoring unit 1151 that monitors the power supply state of the main power supply 116. When the power supply monitoring unit 1151 detects that the power of the main power supply 116 has been cut off due to a power failure or the like, The power supply source can be switched to the auxiliary power supply 40 or the PoE power receiving port Y. When the power supply monitoring unit 1151 detects the restoration of power supply from the main power supply 116, the power supply circuit 115 can switch the power supply source to the main power supply 116. Note that the power supply circuit 115 can individually supply power to each unit such as the switch unit 113. Therefore, for example, the power supply circuit 115 can limit the power supply destination to the PHY unit 112 and the ports X and Y.

  Hereinafter, the operation of the line concentrator 10 of this embodiment (for example, the line concentrator 10-2 illustrated in FIG. 1) will be described in detail with reference to the flowchart illustrated in FIG. 3 and the operation explanatory diagrams illustrated in FIGS. . However, in the following description, it is assumed that an IP telephone, which is an example of the communication device 30, is connected to the downlink PoE power supply port X, and another concentrator switch 10-1 is connected to the uplink port Y. .

  In this case, the line concentrator 10-2 performs communication (IP telephone) between the IP telephone 30 and the line concentrator switch 10-1 through a communication path indicated by a thick arrow 400 in FIG. Relay). In FIG. 4, the communication path for port #i of the PHY unit 111 is not shown. In the normal mode, the power of the main power supply 116 is supplied through the power supply circuit 115 to all the parts to be fed of the concentrator 10-2.

  In such a normal mode, as shown in FIG. 3, the concentrator 10-2 monitors whether or not a power failure has occurred, for example, by the power supply monitoring unit 1151 (NO route of S10). The presence or absence of the occurrence of a power failure can be detected by receiving an external notification through the uplink port Y of the concentrator 10-2 by the power supply circuit 115 or by an internal notification from the power supply monitoring unit 1151.

  When occurrence of a power failure is detected (YES in S10), the power supply circuit 115 checks whether or not the auxiliary power supply 40 is supported (S20). If the auxiliary power supply 40 is supported (YES in S30), the power supply circuit 115 switches the power supply source from the main power supply 116 to the auxiliary power supply 40 (S30: power supply mode switching).

  When the switching to the auxiliary power supply 40 is completed, the CPU 141 gives a communication path switching instruction (repeater mode setting instruction: see FIG. 5) to the PHY unit 112. Receiving the instruction, the PHY unit 112 connects the port X and the port Y to be communicable within the PHY unit 112 (in other words, in the physical layer) (see S40 in FIG. 3 and FIG. 5).

  Thereby, the communication path 400 (see FIG. 4) of the IP telephone communication in the normal mode is a communication path indicated by a thick arrow 500 in FIG. 5, that is, a communication path that does not pass through the switch unit 113 in a layer higher than the physical layer. The IP telephone communication on the communication path 400 is maintained on the communication path 500 when a power failure occurs. In other words, the relay point in the IP telephone communication concentrator 10-2 is changed from the upper layer switch unit 113 to the lower layer PHY unit 112 during a power failure.

  When the switching to the communication path 500 is completed, the CPU 141, as indicated by reference numeral 501 in FIG. 5, resources (for example, ports # 1 to #n, PHY) that are not necessary for maintaining the IP telephone communication on the communication path 500. Unit 111, switch unit 113, and control unit 114) are instructed to stop power supply circuit 115.

  Upon receiving the instruction, the power supply circuit 115 stops power supply to the ports # 1 to #n, the PHY unit 111, the switch unit 113, and the control unit 114. At this time, power supply to the port X, the port Y, and the PHY unit 112 is maintained (S50 in FIG. 3: power supply mode switching). Thus, the communication path 500 can be reliably ensured by performing the power supply mode switching after the communication path switching is completed.

  By switching the power supply mode, the power supply destination of the auxiliary power supply 40 is limited to the minimum communication resources (port X, port Y, and PHY unit 112) necessary for maintaining IP telephone communication on the communication path 500 ( Power saving operation mode).

  Thereafter, as shown in FIG. 3, it is monitored by the power supply circuit 115 whether or not the restoration of the power failure is detected (S60).

  While the restoration of the power failure is not detected, the power supply circuit 115 checks whether or not the auxiliary power supply 40 is supported (from S60 NO route to S70), and if supported (if YES in S70), the power supply circuit 115 As long as the remaining electric power does not fall below the predetermined threshold value Pt (YES route of S80), the monitoring of power failure recovery is continued (S80). Note that, when the remaining power of the auxiliary power supply 40 falls below the threshold value Pt (NO in S80), the power supply circuit 115 notifies the outside (supplementary power supply cut off) to that effect. For example, the notification may be performed to the concentrator 10-1 via the uplink port Y, or to a maintenance person by turning on a display lamp such as an LED of the concentrator 10-2. Alternatively, or both of these may be performed (S90).

  On the other hand, when recovery from a power failure is detected (YES in S60), the power supply circuit 115 checks whether or not the auxiliary power supply 40 is supported (S100 from YES route in S60), and if it is supported (in S100). If YES, the power supply source is switched from the auxiliary power supply 40 to the main power supply 116 (S110: power supply mode switching).

  When the switching to the main power supply 116 is completed, the power supply circuit 115 causes each unit (see reference numeral 501 in FIG. 5) that has stopped power supply in the power saving operation mode, for example, the ports # 1 to #n, the PHY unit 111, and the switch unit. 113 and the power supply to the control unit 114 are resumed (S120: power supply mode switching). Thereby, the operation of the control unit 114 is resumed, and communication via the downlink port #i of the PHY unit 111 and the switch unit 113 is restored under the control of the control unit 114.

  When power supply to the control unit 114 is resumed by switching the power supply mode, the control unit 114 (CPU 141) instructs the communication path 500 (see FIG. 5) to switch to a state before the occurrence of a power failure (normal mode setting instruction). Is supplied to the PHY unit 112. Receiving the instruction, the PHY unit 112 cancels the setting for connecting the port X and the port Y in the PHY unit 112, and sets the communication path 400 (see FIG. 4) via the switch unit 113 (see FIG. 4). S130). As a result, the relay point in the IP telephone communication concentrator 10-2 is changed (returned) from the lower layer PHY unit 112 to the upper layer switch unit 113.

  Thereafter, the line concentrator 10-2 monitors the occurrence of a power failure again in the normal mode and repeats the above-described processing.

  As described above, according to the present embodiment, the downlink PoE power supply port X and the uplink port Y are communicably connected in the PHY unit 112 (that is, in the physical layer) when the main power supply 116 is powered down. In addition, since the auxiliary power supply destination is limited to the PHY unit 112 and the ports X and Y, the power consumption of the auxiliary power supply 40 at the time of a power failure is reduced, and communication between the ports XY at the time of a power failure (for example, an IP phone) (Communication) time can be extended.

  In addition, since it is not necessary to add an ASIC or FPGA separately for connection between ports XY at the time of a power failure, the configuration and operation control of the line concentrator 10-2 can be simplified, and the cost can be reduced. Can be achieved. The effect of reducing the power consumption of the auxiliary power supply 40 can be increased as the processing capacity of the CPU 141 is higher and the number of downlink ports is larger. That is, since the CPU 141 having a higher processing capability (for example, clock frequency) has a larger power consumption, the power consumption can be reduced by stopping the power supply to the CPU 141 in the power saving operation mode. Also, as the number of downlink ports increases, the scale of the PHY unit 111 and the switch unit 113 increases and the power consumption also increases. Therefore, the power supply to the PHY unit 111 and the switch unit 113 is stopped in the power saving operation mode. The effect of reducing power consumption by being able to do so is great.

(When the concentrator 10-2 supports PoE power reception)
When power is supplied to the uplink port Y of the line concentrator 10-2 by PoE connection, the power supply circuit 115 may set the power supply source at the time of a power failure to the PoE power receiving port Y (dotted arrow 601 in FIG. 6). reference).

  Thereby, the concentrator 10-2 can control the power saving operation mode at the time of the power failure described above using the power received at the PoE power receiving port Y (see arrow 301 in FIG. 3). Accordingly, it is possible to extend the communication time (for example, IP telephone communication) between the ports XY during a power failure. In addition, the power consumption can be reduced according to the processing capability of the CPU 141 and the number of downlink ports. A part of the power received at the PoE power receiving port Y can be relayed (PoE relay) to the NW device connected to the downlink PoE power feeding port X through the PHY unit 112 (dotted arrow in FIG. 6). 602).

  Therefore, even in the line concentrator 10-2 that does not include the auxiliary power supply 40, the operation and communication of the NW device connected to the port X can be maintained. As a result, it is possible to increase the number of NW devices that can guarantee the operation / communication at the time of power failure without increasing the number of auxiliary power sources 40 such as UPS to be prepared in the network 20.

10 Network concentrator (concentrator switch)
20 Network (NW)
30 Communication equipment 40 Backup power supply (auxiliary power supply)
111, 112 Physical layer processing unit (PHY unit)
113 Switch unit 114 Control unit 115 Power supply circuit 116 Main power supply 141 CPU
142 Memory 1151 Power supply monitoring unit X, Y port

Claims (10)

A first port connected to a first network device and capable of supplying power to the first network device;
A second port to which a second network device is connected;
A physical layer processing unit that sets a communication path in the physical layer between the first and second ports at the time of a power failure of the main power supply;
A network concentrator comprising: a power supply circuit that receives supply of auxiliary power during the power failure and limits the supply destination of the auxiliary power to the first port, the second port, and the physical layer processing unit.   The network concentrator according to claim 1, wherein a source of the auxiliary power is an auxiliary power supply outside or inside the network concentrator.   The network concentrator according to claim 1, wherein the supply source of the auxiliary power is the second port that is fed through the second network device.   The network line concentrator according to claim 3, wherein the physical layer processing unit relays a part of the auxiliary power to the first port. When the power supply circuit recovers from a power failure of the main power supply, the power supply by the main power supply is resumed, and the limitation on the power supply destination is canceled.
The network line concentrator according to claim 1, wherein the physical layer processing unit cancels the setting of the communication path. A power control method for a network concentrator comprising: a first port to which a first network device is connected and capable of supplying power to the first network device; and a second port to which a second network device is connected. Because
Processing for setting a communication path in the physical layer between the first and second ports at the time of a power failure of the main power supply;
Processing that receives supply of auxiliary power at the time of the power failure and limits the supply destination of the auxiliary power to the first port, the second port, and a processing unit of a physical layer related to the communication path, Control method.   The power control method according to claim 6, wherein a source of the auxiliary power is an auxiliary power supply outside or inside the network line concentrator.   The power control method according to claim 6, wherein the supply source of the auxiliary power is the second port that is fed through the second network device.   The power control method according to claim 8, wherein a part of the auxiliary power is relayed to the first port during the power failure.   The power control method according to any one of claims 6 to 9, wherein when the power failure of the main power supply is restored, the limitation on the power supply destination and the setting of the communication path are canceled.

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