JP5519549B2 - COMMUNICATION SYSTEM, COMMUNICATION CONTROL METHOD, AND COMMUNICATION DEVICE - Google Patents

Description

  The present invention relates to a technique for switching a communication path when a network failure occurs.

  As a wide-area communication network, for example, as shown in FIG. 5, there is a configuration in which device redundancy is provided in a tree configuration, and an active communication network (system 0) and a standby communication network (system 1) are prepared. A detour route called a shared link composed of link aggregation (LAG) that virtually bundles a plurality of physical lines and treats them as if they were one line between the system 0 and the system 1 Connected with.

  When a failure occurs in the active communication network, the traffic passes through the shared link in order to detour to the protection communication network side. The physical line to be passed depends on various LAG distribution methods (VLAN distribution, input port) Distribution).

JP 2004-173136 A

  However, when a plurality of failures occur in the active communication network, the existing LAG distribution method has a problem that congestion occurs in the shared link depending on how traffic flows. Hereinafter, problems that occur in the conventional LAG distribution method will be described.

  FIG. 6 shows a network configuration used in the description. In the network shown in FIG. 6, the switch SW1 and the communication devices A to E constitute an active communication network, and the switch SW2 and the communication devices A2 to E2 constitute an auxiliary communication network. The corresponding devices of the local communication network are connected by a detour route. The switches SW1 and SW2 are connected by a shared link in which the two communication lines # 1 and # 2 are configured by LAG. Each of the shared link communication lines # 1 and # 2 is connected to ports 6 and 7 of the switch SW1. The communication line connecting the devices is 1 Gbps per line, and the shared link is virtually a 2 Gbps line.

  FIG. 6 illustrates the flow of traffic T1 between the communication apparatuses A and D, traffic T2 between the communication apparatuses B and E, and traffic T3 between the communication apparatuses B and C. Traffic T1 has a VLAN number of 10 and uses a band of 800 Mbps, traffic T2 uses a VLAN number of 20 and uses a band of 500 Mbps, and traffic T3 uses a band of VLAN number 30 and a band of 500 Mbps. .

  First, the case where the VLAN distribution method is used as the LAG distribution method will be described. In the VLAN distribution method, a detour communication line is set according to the VLAN setting. For example, in FIG. 6, it is assumed that the distribution setting is communication line # 1 in which VLANs 10 and 20 are connected to port 6 and communication line # 2 in which VLAN 30 is connected to port 7. With this setting, when a network failure occurs, the traffic of the VLANs 10 and 20 is diverted to the communication line # 1, and the traffic of the VLAN 30 is diverted to the communication line # 2.

  Here, the flow of traffic when a failure occurs in the network will be specifically described. As shown in FIG. 7, when a failure occurs in two places, that is, a communication line connecting the switch SW1 and the communication device A and a communication line connecting the switch SW1 and the communication device B, the portion where the failure occurred is flowing. The traffic T1, T2, T3 is routed through the shared link communication line # 1 because the traffic T1 has the VLAN number 10, and the traffic T2 is routed through the shared link communication line # 1 because the VLAN number is 20. The traffic T3 has a VLAN number of 30 and therefore passes through the shared link communication line # 2. In this case, since the bandwidth of traffic T1 is 800 Mbps and the bandwidth of traffic T2 is 500 Mbps, the total becomes 1.3 Gbps, and congestion occurs in communication line # 1 of the shared link.

  Next, a case where the input port distribution method is used will be described. In the input port distribution method, a detour line is set according to the traffic input port. For example, in FIG. 6, it is assumed that the distribution setting is communication line # 1 in which ports 4 and 5 are connected to port 6 and communication line # 2 in which port 3 is connected to port 7. With this setting, when a network failure occurs, traffic input from the ports 4 and 5 is diverted to the communication line # 1, and traffic input from the port 3 is detoured to the communication line # 2.

  Also in this case, when a failure occurs in two places, a communication line connecting the switch SW1 and the communication apparatus A and a communication line connecting the switch SW1 and the communication apparatus B, the traffic flow as shown in FIG. Congestion occurs in communication line # 1.

  Thus, when LAG distribution is performed by the VLAN distribution method or the input port distribution method, congestion may occur in the shared link depending on the traffic band.

  Further, it is possible to register the MAC address of a communication terminal connected to the network so that traffic can be distributed in advance, but this is not realistic.

  The present invention has been made in view of the above, and an object of the present invention is to suppress the occurrence of congestion in a detour route configured by a plurality of communication lines.

  In the communication system according to the first aspect of the present invention, a communication apparatus for determining and transmitting a communication line to which the packet is to be transmitted based on address information included in the input packet is provided for each of the active communication network and the standby communication network. The communication device is connected by a plurality of communication lines to form a detour path, and when a failure occurs in the active communication line connected to the communication device on the active communication network side, A communication system for flowing a packet flowing through a communication line to the bypass route, wherein the communication device on the active communication network side connects a communication line and inputs / outputs packets, the port and the address information Storing means in association with each other, transfer means for determining and sending out a port to which a packet inputted with reference to the storage means should be sent, and failure of a communication line connected to the port A detecting means for detecting, and when the detecting means detects a failure, the address information stored in association with the port where the failure is detected is read from the storage means, and the address information is configured as the detour path A communication device on the standby communication network side through the communication line connected to the other port and storing the address information in the storage means in association with another port to which any of the communication lines connected is connected A copy unit for notifying to the backup communication network, when the communication device on the backup communication network side receives the address information from any of the communication lines constituting the bypass route, The packet which has as information has a setting means which sets so that it may send out to the communication line which received the said address information among the communication circuits which comprise the said detour route It is characterized in.

  The communication control method according to the second aspect of the present invention provides a communication apparatus for determining a communication line to which a packet is to be transmitted based on address information included in the input packet and transmitting the communication device to the active communication network and the standby communication network. When a failure occurs in the active communication line connected to the communication device on the active communication network side, each of the communication devices is connected by a plurality of communication lines to form a detour path. A communication control method for flowing a packet flowing through the communication line to the bypass path, wherein the communication device on the active communication network side associates the communication line and inputs / outputs a packet and associates the address information Determining and transmitting a port to which an input packet should be transmitted with reference to storage means for storing; detecting a failure in a communication line connected to the port; and detecting When a failure is detected in the step, the address information stored in association with the port where the failure is detected is read from the storage means, and the address information is connected to one of the communication lines constituting the bypass path And storing in the storage means in association with the other port, and notifying the address information to a communication device on the backup communication network side via a communication line connected to the other port. When the address information is received from any of the communication lines constituting the bypass path by the communication device on the standby communication network side, a packet having the address information as the address information of the transmission source uses the bypass path. A step of setting the address information to be transmitted to the received communication line in the communication circuit to be configured; .

  A communication apparatus according to a third aspect of the present invention is a communication apparatus for determining and transmitting a communication line to which the packet is to be transmitted based on address information included in the input packet, the communication apparatus on the standby communication network side A plurality of ports that are connected to each other by a plurality of communication lines to form a detour path, connect the communication lines and input / output packets, and storage means that associates and stores the ports and the address information; A transfer unit that determines and sends out a port to which a packet input by referring to the storage unit is to be sent, a detection unit that detects a failure of a communication line connected to the port, and the detection unit detects a failure. When the address information stored in association with the port in which a failure has been detected is read from the storage means, the address information is read from any of the communication lines constituting the detour path. And storing in the storage means in association with another port that is continued, duplication means for notifying the address information to the communication device on the backup communication network side via a communication line connected to the other port, It is characterized by having.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the congestion by the detour route comprised by the some communication line can be suppressed.

It is a functional block diagram which shows the structure of the communication apparatus in this Embodiment. It is a figure which shows the example of the network constructed | assembled using the communication apparatus in this Embodiment. It is a figure explaining the operation | movement which the communication apparatus in this Embodiment sets traffic distribution. It is a figure which shows the flow of the traffic after setting traffic distribution. It is a figure which shows the example of a wide communication network. It is a figure which shows the structure of a network. It is a figure which shows a mode when congestion generate | occur | produces in the detour path | route of the network of FIG.

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

  FIG. 1 is a functional block diagram showing a configuration of a communication apparatus according to the present embodiment. The communication device 1 shown in the figure includes a plurality of communication units 11, a failure detection unit 12, and a table duplication unit 13. Each communication unit 11 includes a transfer unit 111 and an FDB table storage unit 112, and a communication line is connected to each of the ports 1, 2,. Some (for example, two) of the connected communication lines are connected to a communication device of a backup communication network, and become a shared link configured by LAG. The communication device 1 is, for example, an L2 switch.

  The transfer unit 111 distributes the packet to another communication unit 11 based on the header of the packet and the FDB table held by the FDB table storage unit 112 of each communication unit 11 and transmits the packet. Further, when a packet is input from a path connected to the communication unit 11, the transmission source information included in the packet is acquired and registered in the FDB table. Specifically, the MAC address of the transmission source is acquired from the input packet, and is registered in the FDB table storage unit 112 included in the communication unit 11 that has input the packet. Thus, since the port number and the MAC address are associated, when the transfer unit 111 inputs a packet, the destination MAC address in the packet is referred to and the packet is transmitted to the communication unit 11 that holds the FDB table in which the destination MAC address is registered. Is sent to the intended destination.

  The failure detection unit 12 detects that a failure has occurred in the communication line connected to the communication unit 11, and identifies the communication line and port where the failure has occurred.

  The table duplicating unit 13 reads the FDB table from the FDB table storage unit 112 of the communication unit 11 having the port to which the communication line in which the failure has occurred is connected, and any communication in which the communication line constituting the shared link is connected. The data is stored in the FDB table accumulation unit 112 of the unit 11. As a result, the packet addressed to the MAC address registered in the FDB table is sent to the backup communication network side via the communication line connected to the port of the communication unit 11 storing the FDB table. Further, in order to specify the communication line for returning packets, the MAC address registered in the copied FDB table is set to the standby communication network side via the communication line connected to the FDB table copy destination communication unit 11. To the communication device. When the communication device on the backup communication network side receives the notification of the MAC address, the communication device is set so that the packet having the MAC address as the transmission source is transmitted to the communication line that has received the notification.

  Next, a network constructed using the communication device in this embodiment will be described. FIG. 2 is a diagram illustrating an example of a network constructed using the communication device according to the present embodiment.

  An active communication network is constructed by the switch SW1 and the communication devices A to E, which are communication devices in the present embodiment, and a standby communication network is constructed by the switch SW2 and the communication devices A2 to E2, and each device of the active communication network and the standby system are constructed. Each corresponding device of the communication network is connected by a communication line as a bypass route. The switches SW1 and SW2 are connected by a shared link in which the two communication lines # 1 and # 2 are configured by LAG. The bandwidth of the communication line connecting the devices is 1 Gbps, and the shared link is a line having a virtual bandwidth of 2 Gbps.

  User terminals 3A to 3E are connected to the communication devices A to E at the ends of the network, and the MAC addresses of the user terminals 3A to 3E are A, B, C, D, and E, respectively. Of course, a plurality of user terminals may be connected to one communication device, but only one user terminal is shown here for simplicity. In FIG. 2, traffic T1 to T3 flows between user terminals 3A and 3D, between user terminals 3B and 3E, and between user terminals 3B and 3C, and bands of 800 Mbps, 500 Mbps, and 500 Mbps are allocated, respectively. And Since the bandwidth used in any path does not exceed 1 Gbps, congestion does not occur. FIG. 2 illustrates a packet P1 from the user terminal 3A to the user terminal 3D and a packet P2 from the user terminal 3D to the user terminal 3A. The packets P1 and P2 have a destination MAC address and a source MAC address.

  The switch SW1 includes seven ports 1 to 7, ports 1 to 5 are connected to communication lines connected to the communication devices A to E, and ports 6 and 7 are communication lines # constituting a shared link. 1, # 2 are connected. The FDB tables FDB1 to FDB5 shown in FIG. 2 are registered in the FDB table storage units 112 corresponding to the ports 1 to 5, respectively. For example, the FDB table storage unit 112 corresponding to the port 1 stores the FDB table FDB1 in which the MAC address: A of the user terminal 3A is registered. In the FDB table, the source MAC address of the packet input to the switch SW1 is registered. For example, when the packet P1 in FIG. 2 is input from the port 1, the MAC address: A is registered in the FDB table in association with the port 1 from the transmission source MAC address (SA: A) of the packet P1. Further, the packet P1 is sent to the port 4 corresponding to the MAC address: D from the destination MAC address (DA: D) of the packet P1 and the FDB table FDB4.

  Next, the operation of the switch SW1 when a failure occurs in two places, that is, a communication line connecting the switch SW1 and the communication apparatus A and a communication line connecting the switch SW1 and the communication apparatus B will be described.

  FIG. 3 is a diagram for explaining an operation in which the communication device (switch SW1) in this embodiment sets traffic distribution.

  When the failure detection unit 12 detects a failure in the path (communication with the communication device A) connected to the port 1 (step S11), the table replication unit 13 retrieves the FDB table from the FDB table storage unit 112 corresponding to the port 1. The read FDB table is copied to the FDB table storage unit 112 corresponding to the port 6 connected to the read and shared link, and the MAC address: A is associated with the port 6 (step S12). As a result, a packet whose destination MAC address is A is transmitted from the port 6.

  Then, the table replicating unit 13 sends the copied MAC address information from the port 6 and notifies the switch SW2 via the communication line # 1 (step S13). When the notified MAC address receives the packet of the transmission source, the switch SW2 sets the packet to be transferred to the communication line # 1 that has notified the MAC address. In this case, when the source MAC address is A, that is, when the switch SW2 receives a packet transmitted from the user terminal 3A, the packet is transferred to the communication line # 1 connected to the port 6 of the switch SW1. In addition, LLDP (Link Layer Discovery Protocol) can be used for notification of the MAC address.

  On the other hand, when the failure detection unit 12 detects a failure in the path (communication with the communication apparatus B) connected to the port 2 (step S21), the table replication unit 13 sends the FDB from the FDB table storage unit 112 corresponding to the port 2 to the FDB. The table is read, the read FDB table is copied to the FDB table storage unit 112 corresponding to the port 7 to which the shared link is connected, and the MAC address: B is associated with the port 7 (step S22). As a result, a packet whose destination MAC address is B is transmitted from the port 7. Since the FDB table of another port has already been copied to port 6, the FDB table has been copied to port 7 that has not been used here.

  Then, the table replication unit 13 sends the copied MAC address information from the port 7 and notifies the switch SW2 via the communication line # 2 (step S23). When the notified MAC address receives the packet of the transmission source, the switch SW2 sets the packet to be transferred to the communication line # 2 that has notified the MAC address. In this case, when the source MAC address is B, that is, when the switch SW2 receives a packet transmitted from the user terminal 3B, the packet is transferred to the communication line # 2 connected to the port 7 of the switch SW1.

  In this way, a traffic detour route is set.

  FIG. 4 shows the flow of traffic after setting traffic distribution.

  As described above, the MAC address: A of the user terminal 3A is registered in the FDB table storage unit 112 corresponding to the port 6 of the switch SW1, and the FDB table storage unit 112 corresponding to the port 7 is registered in the FDB table storage unit 112. MAC address: B is registered. As a result, a packet whose destination MAC address is A input to the switch SW1 is sent out from the port 6, and a packet whose destination MAC address is B is sent out from the port 7. For example, since the destination MAC address of the packet from the user terminal 3D to the user terminal 3A in FIG. 4 is A, the packet is sent from the port 6 of the switch SW1 and reaches the communication device A via the switches SW2 and A2. Since the packet destined for the user terminal 3B from the user terminal 3E has a destination MAC address B, the packet is sent from the port 7 of the switch SW1 and reaches the communication device B via the switches SW2 and B2. Further, since the destination MAC address of the packet from the user terminal 3C to the user terminal 3B is B, the packet is transmitted from the port 7 of the switch SW1 and reaches the communication device B via the switches SW2 and B2.

  On the other hand, when the source MAC address of the received packet is the MAC address notified from the switch SW1, the switch SW2 is set to forward to the communication lines # 1 and # 2 used for notification of the MAC address. ing. For example, a packet directed from the user terminal 3A to the user terminal 3D is transmitted from the communication line # 1 and reaches the communication device D via the switch SW1 because the source MAC address is A. A packet directed from the user terminal 3B to the user terminal 3E is transmitted from the communication line # 2 and reaches the communication device E via the switch SW1 because the source MAC address is B. Further, since the packet from the user terminal 3B to the user terminal 3C has a transmission source MAC address B, the packet is transmitted from the communication line # 2 and reaches the communication apparatus C via the switch SW1.

  In this way, by copying the FDB table, a packet that is originally transmitted from port 1 is transmitted from port 6, and a packet that is transmitted from port 2 is transmitted from port 7. In addition, packets from the switch SW2 to the switch SW1 are also input from the port 6 if the packet is originally input from the port 1 and from the port 7 if the packet is input from the port 1 according to the ports 1 and 2 of the copy source. Entered. As a result, traffic input / output to / from the port connected to the communication line in which the failure has occurred can be directly distributed to input / output to the port to which the shared link is connected. In each # 2, traffic exceeding 1 Gbps, which is the bandwidth of the communication line where the failure has occurred, does not flow.

  In the present embodiment, since a shared link is formed by two communication lines, it is possible to cope with failures in two or more communication lines at the same time. I can not cope. The failure of three or more communication lines can be dealt with by configuring a shared link as a detour path with three or more communication lines.

  As described above, according to the present embodiment, when the failure detection unit 12 detects a failure, the FDB table storage unit 112 of the communication unit 11 to which the table replication unit 13 connects the communication line in which the failure is detected. Is read out from the FDB table and copied to the FDB table storage unit 112 of any of the communication units 11 connected to the communication lines # 1 and # 2 constituting the shared link that is a detour route, and registered in the copied FDB table. The packet that was input / output to / from the port where the failure was detected by notifying the opposite communication device via the communication lines # 1 and # 2 connected to the communication unit 11 that copied the FDB table. Since the port of the communication unit 11 that copied the FDB table is input / output, even if multiple faults are detected, the port that connects the shared link Traffic flowing through each door, the congestion in the shared link does not occur because the disorder is not the same as that of each port that has been detected traffic.

DESCRIPTION OF SYMBOLS 1 ... Communication apparatus 11 ... Communication part 111 ... Transfer part 112 ... FDB table storage part 12 ... Failure detection part 13 ... Table replication part AE, A2-E2 ... Communication apparatus T1, T2, T3 ... Traffic 3A-3E ... User Terminal

Claims (3)

Based on the address information included in the input packet, a communication device that determines and transmits a communication line to which the packet is to be transmitted is arranged in each of the active communication network and the standby communication network, and a plurality of communication devices are arranged between the communication devices. To establish a bypass route, and when a failure occurs in the active communication line connected to the communication device on the active communication network side, a packet flowing through the communication line is sent to the bypass route A communication system,
The communication device on the active communication network side is:
A plurality of ports for inputting and outputting packets by connecting communication lines;
Storage means for storing the port and the address information in association with each other;
Transfer means for determining and sending out a port to which a packet input with reference to the storage means is to be sent;
Detecting means for detecting a failure of a communication line connected to the port;
When the detection unit detects a failure, the address information stored in association with the port where the failure is detected is read from the storage unit, and the address information is one of the communication lines constituting the detour path. Is stored in the storage unit in association with another port connected to the communication port, and the address unit is notified to the communication device on the standby communication network side via the communication line connected to the other port; Have
The communication device on the standby communication network side is:
When the address information is received from any of the communication lines that constitute the bypass route, the packet having the address information as the source address information is the communication that has received the address information among the communication circuits that constitute the bypass route. A communication system characterized by comprising setting means for setting to transmit to a line. Based on the address information included in the input packet, a communication device that determines and transmits a communication line to which the packet is to be transmitted is arranged in each of the active communication network and the standby communication network, and a plurality of communication devices are arranged between the communication devices. To establish a bypass route, and when a failure occurs in the active communication line connected to the communication device on the active communication network side, a packet flowing through the communication line is sent to the bypass route A communication control method,
By the communication device on the working communication network side,
Determining and sending out a port to which the input packet is to be sent with reference to a storage means for storing the address information in association with a port for connecting and receiving a packet by connecting a communication line;
Detecting a failure of a communication line connected to the port;
When a failure is detected in the detecting step, the address information stored in association with the port where the failure is detected is read from the storage unit, and the address information is selected from any of the communication lines constituting the detour path. Storing in the storage means in association with another port connected to the port, and notifying the address information to a communication device on the backup communication network side via a communication line connected to the other port; Have
By the communication device on the standby communication network side,
When the address information is received from any of the communication lines that constitute the bypass route, the packet having the address information as the source address information is the communication that has received the address information among the communication circuits that constitute the bypass route. A communication control method comprising a step of setting to transmit to a line. A communication device for determining and transmitting a communication line to which the packet should be transmitted based on address information included in the input packet,
Connect to communication devices on the standby communication network side with multiple communication lines to configure a detour route,
A plurality of ports for inputting and outputting packets by connecting communication lines;
Storage means for storing the port and the address information in association with each other;
Transfer means for determining and sending out a port to which a packet input with reference to the storage means is to be sent;
Detecting means for detecting a failure of a communication line connected to the port;
When the detection unit detects a failure, the address information stored in association with the port where the failure is detected is read from the storage unit, and the address information is one of the communication lines constituting the detour path. Is stored in the storage unit in association with another port connected to the communication port, and the address unit is notified to the communication device on the standby communication network side via the communication line connected to the other port; ,
A communication apparatus comprising:

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