JP2009302875A - Receiving side network device, relay device, transmitting side network device, and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a receiving side network device for constructing a highly reliable network. <P>SOLUTION: The receiving side network device is provided with: internal deterioration detection parts 22-1 and 22-2 which are connected to a transmitting side network device 1 via L2 networks #1 and #2, and detect data amounts, for example, of received signals for each path; a signal blocking part 24 which switches whether to pass or block the received signals; and an blocking control part 23 which compares the data amounts detected in two paths with each other, and controls the signal blocking part 24 so as to block the signal received from one path with the smaller data amount when difference between the data amounts exceeds a predetermined threshold. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication system for transmitting and receiving signals via a layer 2 network.

  As a conventional high-reliability network device, there is a receiving-side network device that is connected to a transmitting-side network device through a network that forms a plurality of paths and receives a redundant signal from the transmitting-side network device (described below) , See Patent Document 1). This receiving-side network device ensures high reliability by detecting deterioration of the received signal and blocking the signal of the network network according to the result.

JP 2008-28671 A

  However, when the packet loss occurs in the network, the receiving-side network device in the conventional technique cannot detect the loss as signal degradation, and therefore continues to receive the signal from the network in which the signal loss has occurred. End up. That is, there is a problem that a signal from a network in which signal loss has occurred is allowed to pass even though there is a network in which no packet loss has occurred.

  The present invention has been made in view of the above, and an object thereof is to obtain a reception-side network device, a relay device, a transmission-side network device, and a communication system that can construct a more reliable network.

  In order to solve the above-described problems and achieve the object, the present invention is connected to a transmission-side network device through a network network that forms a plurality of paths, and is made redundant by being transmitted from the transmission-side network device. A receiving-side network device that receives a signal, and performs switching between in-network deterioration detecting means for detecting the data amount of the signal received from the plurality of paths for each path and whether the received signal is allowed to pass or blocked. Based on the detection results by the signal blocking means and the in-network deterioration detection means, all data amounts detected by the plurality of paths are individually compared with other data amounts, and the difference in the data amount is a predetermined value. When there is a path exceeding the threshold, the signal blocking unit is configured to block a signal received from one of the two paths to be compared with a small amount of data. And Gosuru interruption control means, characterized in that it comprises a.

  According to the present invention, the communication quality is improved, and there is an effect that a more reliable network can be constructed.

  Embodiments of a communication system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of a communication system according to the first embodiment. In the communication system of FIG. 1, a transmission-side network device 1 and a reception-side network device 2 are connected to a layer 2 network (hereinafter also referred to as “L2 network”). In the L2 network, a plurality of routes (L2 network # 1 and # 2) are formed by the relay devices 3 and 4.

  The transmission-side network device 1 includes a reception processing unit 11 that receives a packet (signal), and a redundancy processing unit 12 that makes the packet (signal) redundant in correspondence with the relay devices 3 and 4.

  The reception-side network device 2 includes signal degradation detection units 21-1 and 21-2, in-network degradation detection units 22-1 and 22-2, a cutoff control unit 23, a signal cutoff unit 24, and a redundancy processing unit. 25 and a transmission processing unit 26.

  The signal degradation detection units 21-1 and 21-2 of the reception-side network device 2 detect degradation of packets received from the corresponding relay devices in the L2 network. The in-network degradation detection units 22-1 and 22-2 count the number of input packets in order to detect packet loss due to in-network degradation. The blocking control unit 23 controls the signal blocking unit 24 based on information obtained from each detection unit, and the signal blocking unit 24 blocks packets received from the deteriorated L2 network. The redundancy processing unit 25 processes a redundant packet received from the L2 network. The transmission processing unit 26 transmits the packet to a terminal device or the like. In FIG. 1, the signal deterioration detection unit 21-1 and the in-network deterioration detection unit 22-1 are connected to the L2 network # 1, and the signal deterioration detection unit 21-2 and the in-network deterioration detection unit 22-2 are set to L2. Each is connected to the network # 2.

  Next, the operation of the network device configured as described above will be described. When the reception processing unit 11 of the transmission side network device 1 receives a packet transmitted from a terminal device or the like, the redundancy processing unit 12 makes the packet redundant, and transmits the redundant packet to the relay device 3 in the L2 network and Send to 4

  The relay apparatuses 3 and 4 transfer the packet received from the transmission side network apparatus 1 to the reception side network apparatus 2.

  The signal degradation detection units 21-1 and 21-2 of the reception-side network device 2 receive signals from the corresponding L2 network (# 1, # 2), respectively. The signal degradation detection units 21-1 and 21-2 perform signal degradation detection processing on the received packets, and notify the cutoff control unit 23 when degradation is detected. Further, the received signals are output to the corresponding in-network deterioration detection units (22-1 and 22-2), respectively. The in-network deterioration detection units 22-1 and 22-2 accumulate the number every time a packet is received, and notify the interruption control unit 23 of the accumulation result. Further, the received signal is output to the signal blocking unit 24.

  The blocking control unit 23 monitors the deterioration of the packets notified from the signal deterioration detection units 21-1 and 21-2, and if the deterioration frequency exceeds a predetermined threshold, the signal deterioration is detected in the L2 network. The signal blocking unit 24 is controlled so as to block the packet from the network.

  Further, the blocking control unit 23 compares the packet integration results notified from the in-network deterioration detection units 22-1 and 22-2. Then, when the difference between the integration results exceeds a predetermined threshold, the cutoff control unit 23 determines that a packet loss has occurred in the L2 network with the smaller integration result, and blocks the packets from that network. Thus, the signal blocking unit 24 is controlled. Since the cutoff control unit 23 performs control so as not to block a received signal from at least one L2 network, any one of the L2 networks is already notified by notification from the signal degradation detection units 21-1 and 21-2. In the case of blocking, the other L2 network is not blocked.

  The signal blocking unit 24 receives the packets output from the in-network deterioration detecting units 22-1 and 22-2, and is determined to have no packet loss in accordance with the control by the blocking control unit 23. Are output to the redundancy processing unit 25. The redundancy processing unit 25 processes the redundant packet and outputs it to the transmission processing unit 26, and the transmission processing unit 26 transmits the packet to a terminal device or the like.

  For example, it is assumed that a packet loss occurs in the L2 network network # 1, while the L2 network network # 2 is normal. In this case, the number of packets received by the in-network deterioration detection unit 22-1 is smaller than the number of packets received by the in-network deterioration detection unit 22-2. Therefore, the signal blocking unit 24 blocks the packet from the in-network deterioration detecting unit 22-1 and transfers only the packet from the in-network deterioration detecting unit 22-2 to the redundancy processing unit 25. That is, the receiving-side network device 2 can transmit a packet to the subsequent terminal device without being affected by the network network (L2 network network # 1) in which the packet loss has occurred.

  Further, after the L2 network network is cut off, if the cut-off control unit 23 determines that the L2 network network has been repaired, it controls the signal cut-off unit 24 to release the cut-off and pass packets from the L2 network network. Let it resume.

  As described above, in this embodiment, each time the receiving-side network device receives packets from the L2 network, the number of packets is accumulated, and the packet loss for each L2 network is reduced by comparing the accumulated results. The packet from the L2 network that was detected and determined that no packet loss occurred was passed. Thereby, in the receiving side network device, the signal from the L2 network where the packet loss has occurred is not selected, and only the signal with less degradation in the network can be transmitted to the subsequent terminal device, so that the communication quality can be improved, A more reliable network can be constructed.

  In addition, since the cutoff control unit performs control so as not to cut off the reception signal from at least one L2 network, it is possible to suppress the influence of the degradation within the network while the degradation within the network occurs in all the L2 network networks. Even if there is, communication is possible.

  In this embodiment, each time the in-network degradation detection units 22-1 and 22-2 receive packets, the number is added and the result is notified to the cutoff control unit 23. However, the packets are detected. It is also possible to notify that effect each time the information is sent, and the blocking control unit 23 may accumulate the number of received packets.

  Further, in the present embodiment, the case where there are two L2 network networks has been described for convenience of explanation, but the present invention can also be applied to the case where there are three or more routes. In that case, the shut-off control unit performs individual comparisons with other integrated amounts for all integrated amounts detected for each route. Then, when there is a path where the difference between the integrated amounts exceeds a predetermined threshold, the signal blocking means is controlled so as to block packets from one of the paths with a small integrated amount.

Embodiment 2. FIG.
In the first embodiment, the receiving side network device adds the number of packets every time it receives a packet from the L2 network, and compares packet integration results for each network to detect packet loss due to degradation in the network. . In the present embodiment, a case will be described in which the relay apparatus transmits packet loss information. In addition, about the structure similar to Embodiment 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  FIG. 2 is a diagram illustrating a configuration example of a communication system according to the second embodiment. The communication system of FIG. 2 is different from the communication system of FIG. 1 in that the reception-side network device 2B is replaced by the reception-side network device 2B, the relay device 3B is replaced by the relay device 3, and the relay device 4 is replaced by the relay device. 4B is provided. In the following, the characteristics of the present embodiment will be described by taking the relay device 3B as an example, but the relay device 4B has the same function as the relay device 3B.

  The receiving-side network device 2B includes in-network deterioration detecting units 27-1 and 27-2 instead of the in-network deterioration detecting units 22-1 and 22-2, and a blocking control unit 23B instead of the blocking control unit 23. Yes. The blocking control unit 23B controls the signal blocking unit 24 based on information obtained from the signal deterioration detection units (21-1, 21-2) and the in-network deterioration detection units (27-1, 27-2). Unlike in-network degradation detection units 22-1 and 22-2, in-network degradation detection units 27-1 and 27-2 detect signal loss information transmitted from the relay device.

  The relay device 3B is a device that relays a packet received from the transmission-side network device 1, and includes a signal deterioration detection unit 31, a signal loss information transmission unit 32, and a signal transfer unit 33. The signal degradation detection unit 31 receives the packet and outputs it to the signal transfer unit 33. Further, when the signal degradation detection unit 31 detects degradation of the received packet, the signal degradation detection unit 31 discards the packet and notifies the signal loss information transmission unit 32 of the detection result. The signal loss information transmission unit 32 creates signal loss information indicating that a packet is lost based on the detection result from the signal degradation detection unit 31 and outputs the signal loss information to the signal transfer unit 33. The signal transfer unit 33 relays the received packet and transmits signal loss information.

  Next, the operation of the communication system configured as described above will be described. When the packet is transmitted from the transmission side network device 1, the signal deterioration detection unit 31 of the relay device 3 </ b> B outputs the received packet to the signal transfer unit 33. At this time, the signal degradation detection unit 31 performs a parity check or the like on the received packet, discards the packet when it is determined that the packet is degraded based on a predetermined criterion, and informs the signal loss information transmission unit 32. Note that the signal degradation detection method here may be the same as the processing by the signal degradation detection units 21-1 and 21-2 in the first embodiment, or other methods may be used. When receiving the notification from the signal deterioration detection unit 31, the signal loss information transmission unit 32 generates signal loss information and outputs it to the signal transfer unit 33. The signal transfer unit 33 transmits the received packet and signal loss information to the receiving-side network device 2B. Henceforth, in this Embodiment, the case where the relay apparatus 3B transmits signal loss information toward the receiving side network apparatus 2B is described as an example.

  When detecting the signal loss information from the relay device 3B, the in-network degradation detection unit 27-1 of the reception-side network device 2B notifies the cutoff control unit 23B to that effect. When receiving the notification that the signal loss information has been detected from the in-network deterioration detecting unit 27-1, the blocking control unit 23B sends a signal to block the packet from the corresponding L2 network network (L2 network network # 1). The blocking unit 24 is controlled. In addition, since the cutoff control unit 23B performs control so as not to block a received signal from at least one L2 network, if any L2 network is already blocked by a notification from the signal deterioration detection unit, The other L2 network is not blocked.

  Thus, the signal degradation detected by the relay device 3B is notified to the receiving side network device 2B as signal loss information, and the signal blocking unit 24 blocks the packet of the L2 network # 1 based on this notification. Therefore, only the packet from the L2 network # 2 is output from the signal blocking unit 24 to the redundancy processing unit 25 and transmitted to an external terminal device or the like via the transmission processing unit 26.

  As described above, in the present embodiment, the relay apparatus in the L2 network notifies the reception side network apparatus of the signal loss information to detect that the signal loss has occurred. As a result, the receiving-side network device does not select a signal from the L2 network that has undergone in-network degradation, and can transmit a signal with less in-network degradation to subsequent terminal devices, thereby improving communication quality. Note that the processing of the present embodiment can be similarly applied when there are three or more routes.

Embodiment 3 FIG.
In the first embodiment, every time packets are received from the L2 network, the number is added and compared to detect the L2 network where packet loss has occurred. In the present embodiment, a case where the transmission side network device transmits information indicating the number of transmission packets will be described. In addition, about the structure similar to Embodiment 1 mentioned above, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  FIG. 3 is a diagram illustrating a configuration example of a communication system according to the third embodiment. Compared with the communication system of FIG. 1, the communication system of FIG. 3 includes a transmission-side network device 1 </ b> C instead of the transmission-side network device 1 and a reception-side network device 2 </ b> C instead of the reception-side network device 2.

  In addition to the components of the transmission side network device 1, the transmission side network device 1C includes a signal information transmission unit 13 that transmits transmission signal information indicating the number of packets transmitted by the transmission side network device 1C.

  Compared with the receiving-side network device 2, the receiving-side network device 2C replaces the in-network deterioration detecting units 22-1 and 22-2 with the in-network deterioration detecting units 28-1 and 28-2 and the blocking control unit 23. Instead, a cutoff control unit 23C is provided. In addition to counting the number of input packets, the in-network deterioration detection units 28-1 and 28-2 acquire transmission signal information in the same manner as the in-network deterioration detection units 22-1 and 22-2, Notify the cutoff control unit 23C. The blocking control unit 23C compares the transmission signal information notified from the in-network deterioration detecting units 28-1 and 28-2 with the number of received packets, and controls the signal blocking unit 24 based on the comparison result.

  Next, the operation of the communication system configured as described above will be described. When receiving the packet from the redundancy processing unit 12, the signal information transmission unit 13 of the transmission-side network device 1C transmits the packet. Also, the number of packets transmitted by itself is calculated, and transmission signal information storing the number is created and transmitted. In FIG. 3, transmission signal information is shown on the L2 network # 2 as a representative.

  The in-network degradation detection units 28-1 and 28-2 of the receiving-side network device 2C accumulate the number every time a packet is received. Further, the number of transmission packets is acquired from the received transmission signal information. Then, they are notified to the cutoff control unit 23C. The blocking control unit 23C calculates the ratio of the number of received packets (accumulation result) to the number of transmitted packets for each L2 network based on notifications from the in-network deterioration detection units 28-1 and 28-2.

  When the calculated ratio falls below a predetermined threshold, the blocking control unit 23C determines that packet loss has occurred in the corresponding L2 network. For example, if it is determined that a packet loss has occurred in the L2 network # 2, the cutoff control unit 23C blocks the packet from the L2 network # 2 received by the in-network degradation detection unit 28-2. The signal blocking unit 24 is controlled. In addition, since the cutoff control unit 23C controls so as not to block the received signal from at least one L2 network, if any L2 network is already blocked by the notification from the signal degradation detection unit, The other L2 network is not blocked.

  Further, the number of packets stored in the transmission signal information is calculated in units such as VLAN (Virtual LAN) in which the order of the IP address and the packet does not reverse.

  As described above, in this embodiment, the transmission side network device transmits information indicating the number of transmitted packets, and the reception side network device compares the number of packets actually received, thereby causing degradation in the network. It was decided to detect. Thereby, degradation in the network can be detected with high accuracy, and communication quality can be improved. Note that the processing of the present embodiment can be similarly applied when there are three or more routes.

  As described above, the communication system according to the present invention is useful for a system that transmits and receives signals via a layer 2 network, and is particularly suitable for the construction of a highly reliable network.

1 is a diagram illustrating a configuration example of a communication system according to a first embodiment. 6 is a diagram illustrating a configuration example of a communication system according to a second embodiment. FIG. 6 is a diagram illustrating a configuration example of a communication system according to Embodiment 3. FIG.

Explanation of symbols

1, 1C Transmission side network device 2, 2B, 2C Reception side network device 3, 3B, 4, 4B Relay device 11 Reception processing unit 12, 25 Redundancy processing unit 13 Signal information transmission unit 21-1, 21-2 Signal degradation Detection unit 23, 23B, 23C Blocking control unit 24 Signal blocking unit 25 Redundancy processing unit 26 Transmission processing unit 22-1, 22-2, 27-1, 27-2, 28-1, 28-2 Intra-network degradation detection Unit 31 Signal degradation detection unit 32 Signal loss information transmission unit 33 Signal transfer unit

Claims (10)

A receiving network device connected to a transmitting network device via a network forming a plurality of paths and receiving a redundant signal transmitted from the transmitting network device;
In-network deterioration detection means for detecting the data amount of signals received from the plurality of paths for each path;
A signal blocking means for switching between passing or blocking a received signal; and
Based on the detection result by the in-network deterioration detecting means, all the data amounts detected in the plurality of routes are individually compared with other data amounts, and there is a route in which the difference in the data amount exceeds a predetermined threshold value. A blocking control unit that controls the signal blocking unit so as to block a signal received from one of the two paths with a small amount of data of the two paths to be compared,
A receiving-side network device comprising: A receiving network device connected to a transmitting network device via a network that forms a plurality of paths via a relay device and receiving a redundant signal transmitted from the transmitting network device;
In-network deterioration detection means for detecting signal loss information for each path indicating that the signal is lost from the signals transmitted by the relay device;
A signal blocker for switching whether to pass or block the received signal; and
When the signal loss information is detected by the in-network deterioration detection unit, a blocking control unit that controls the signal blocking unit to block a signal received from a corresponding path;
A receiving-side network device comprising: A receiving network device connected to a transmitting network device via a network forming a plurality of paths and receiving a redundant signal transmitted from the transmitting network device;
Detecting the amount of data of the signals received from the plurality of paths for each path, and further detecting in-network deterioration detection means for detecting signal information indicating the amount of transmission data from the signals transmitted by the transmission side network device;
A signal blocking means for switching between passing or blocking a received signal; and
When a ratio to the transmission data amount is calculated for all the data amounts detected by the plurality of routes based on the detection result by the in-network deterioration detection unit, and there is a route in which the ratio falls below a predetermined threshold A blocking control means for controlling the signal blocking means so as to block a signal received from the path;
A receiving-side network device comprising:   The receiving-side network device according to claim 1, 2 or 3, wherein the blocking control unit further controls the signal blocking unit so as to pass a signal received from at least one path.   When the blocking control means determines that the deterioration of the signal received from the path has been recovered after blocking the signal received from any path, the signal blocking means is configured to pass the signal received from the path. The receiving-side network device according to claim 1, wherein the receiving-side network device is controlled. A relay device that relays a redundant signal between a receiving-side network device and a transmitting-side network device that are connected via a network that forms a plurality of paths,
A signal degradation detection means for discarding the signal when the degradation of the received signal is detected;
Signal loss information generating means for generating signal loss information indicating that a signal is lost when the signal is discarded by the signal degradation detecting means;
Transmitting a signal whose deterioration is not detected by the signal deterioration detecting means, and further transmitting the signal loss information;
A relay device comprising: A transmission-side network device that is connected to a reception-side network device via a network network that forms a plurality of paths and transmits a redundant signal,
Signal information transmitting means for transmitting signal information indicating the transmission data amount of the signal;
A transmission-side network device comprising: A transmission-side network device that transmits a redundant signal toward a network that forms a plurality of paths;
A receiving-side network device according to claim 1;
A communication system comprising: A transmission-side network device that transmits a redundant signal toward a network that forms a plurality of paths;
A receiving-side network device according to claim 2;
A relay device according to claim 6;
A communication system comprising: A receiving-side network device according to claim 3;
A transmission-side network device according to claim 7;
A communication system comprising:

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