Patent Application
20230103537
The present invention relates to a communication system, a network relay device, a network relay method, and a program to which a multi-chassis link-aggregation (MC-LAG) function is applied.
In recent years, for the purpose of a reduction in network cost, it has been examined to utilize, in a carrier network, a box-type switch widely spread in the data center (DC) market. As means for improving fault tolerance of the box-type switch, there is the multi-chassis link-aggregation technique.
General multi-chassis link-aggregation is used in an “Act/Sby configuration” for loop avoidance or the like of a part of frames (broadcast frames). In the “Act/Sby configuration”, only one of a plurality of relay devices configuring the multi-chassis link-aggregation can transmit a frame to a counter device.
On the other hand, as a method of improving link use efficiency of a network, an “Act/Act configuration” in which all the relay devices are capable of transmitting frames to the counter device has been examined.
For example, Patent Literature 1 described below describes a network device including two counter device connection ports connected to two counter devices having a link-aggregation function, a state monitor unit that monitors a state of failure occurrence of the own device and other network devices, and a frame transfer unit that, when the state monitor unit detects a failure of a physical link in the own device, transmits a frame received from the counter device from a network device connection port to a first SW and, when the state monitor unit does not detect a failure in the own device, transfers the frame received from the counter device to the counter device and does not transfer the frame to the counter device through the first SW. In this technique, the “Act/Act configuration” that does not perform double distribution to the counter device while enabling frame transmission from all network devices configuring multi-chassis link-aggregation to the counter device is realized by only network devices of layer 2.
A communication system 90 includes a plurality of switch devices (a first switch device (SW1) 92 and a second switch device (SW2) 94), which are network relay devices, and two counter devices (a first counter device 96 and a second counter device 98).
It is assumed that frames are transmitted from the first counter device 96 to the second counter device 98 as indicated by arrows in
Each of the switch devices 92 and 94 includes a reception port RP connected to the first counter device 96 and a transmission port SP connected to the second counter device 98. Each of the switch devices 92 and 94 includes a bridge port BP connected to the other switch.
Each of the counter devices 96 and 98 includes a first port P1 connected to the first switch device 92 and a second port P2 connected to the second switch device 94.
In a logical connection configuration of the communication system 90, the first port P1 and the second port P2 of the first counter device 96 are virtually regarded as one port (LAG1) by applying the link-aggregation function to the first port P1 and the second port P2 and the first port P1 and the second port P2 of the second counter device 98 are virtually regarded as one port (LAG2) by applying the link-aggregation function to the first port P1 and the second port P2. The reception port RP of the first switch device 92 and the reception port RP of the second switch device 94 are virtually regarded as one port of one device (MC-LAG1) by applying the multi-chassis link-aggregation function to the reception ports RP and the transmission port SP of the first switch device 92 and the transmission port SP of the second switch device 94 are virtually regarded as one port of one device (MC-LAG2) by applying the multi-chassis link-aggregation function to the transmission ports SP.
When the communication system 90 is normally operating, as shown in
In
On the other hand, when a failure occurs in the communication system 90, for example, when a failure occurs in the transmission port SP of the first switch device 92 as shown in
In
The second switch device 94 receiving the transferred frame refers to the identifier of the reception port included in the frame and determines a transmission destination of the frame. That is, the second switch device 94 transmits the frame without including, in the transmission destination, a port (in the example shown in
In the communication system to which the multi-chassis link-aggregation is applied in this way, communication between the counter devices is enabled even at failure occurrence.
A communication system in which the ports connecting the switches and the counter devices are expanded to pluralities of ports is examined as shown in
A communication system 110 shown in
Each of the switch devices 112 and 114 includes two reception ports RP connected to the first counter device 116 and two transmission ports SP connected to the second counter device 118. That is, each of the switch devices 112 and 114 includes reception ports RP1 and RP2 and transmission ports SP1 and SP2. Each of the switch devices 112 and 114 includes the bridge port BP connected to the other switch.
Each of the counter devices 116 and 118 includes two ports connected to the first switch device 112 and two ports connected to the second switch device 114. That is, each of the counter devices 116 and 118 includes four ports in total including ports P1 and P2 connected to the first switch device 112 and ports P3 and P4 connected to the second switch device 114.
A case in which a failure occurs in the communication system 110 having such a configuration, specifically, a case in which a failure occurs in the transmission port SP1 of the first switch device 112, for example, as shown in
When the related art is applied to a state of such a single failure, the closing between the bridge ports BP is not released. Therefore, all of frames received by the reception ports RP1 and RP2 of the first switch device 112 are transmitted from the transmission port SP2 of the first switch device 112 to the second counter device 118. There is a problem in that congestion easily occurs because of unbalance of traffic.
A configuration in which the first switch device 112 further includes a reception port RP3 and a port P1 of a third counter device 119 is connected to the reception port RP3 (a configuration in which a plurality of devices are connected to the first switch device 112), for example, as shown in
When the related art is applied to such a configuration, all of frames received by the reception ports RP1 to RP3 of the first switch device 112 are transmitted from the transmission port SP1 or SP2 of the first switch device 112 to the second counter device 118. Accordingly, traffic sometimes concentrates on a part of the ports (in the example shown in
The present invention has been devised in view of such points. An object of the present invention is to reduce unbalance of traffic and prevent congestion in a multi-chassis link-aggregation communication system having an Act/Act configuration in which a relay device includes a plurality of ports.
A communication system according to the present invention is a communication system including: counter devices forming a pair; and a plurality of network relay devices connecting the counter devices. Each of the network relay devices includes: a plurality of communication ports provided for each of the counter devices and connecting the own network relay device and the counter device; a bridge port connected to another network relay device; a traffic totalization unit that totalizes, for each of multi-chassis link-aggregation groups set for the communication ports, a traffic amount received by the communication ports of the own network relay device; a failure detection unit that detects whether the communication port of the own network relay device to be a transmission destination of traffic of the multi-chassis link-aggregation group is effective; an other-device-information acquisition unit that acquires a traffic amount for each of multi-chassis link-aggregation groups in the other network relay device and information concerning whether the communication port of the other network relay device is effective; and a traffic bypass unit that transmits a part of the traffic of the multi-chassis link-aggregation group to the other network relay device via the bridge port when a traffic amount per effective communication port in the own network relay device is larger than the traffic amount per the effective communication port in the other network relay device by a threshold or more in the multi-chassis link-aggregation group.
According to the present invention, it is possible to reduce unbalance of traffic and prevent congestion in a multi-chassis link-aggregation communication system having an Act/Act configuration in which a relay device includes a plurality of ports.
Subsequently, a mode for carrying out the present invention (hereinafter referred to as “this embodiment”) is explained.
First, a communication system 10 according to an embodiment of the present invention is explained with reference to
The communication system 10 includes a plurality of switch devices (a first switch device (SW1) 12 and a second switch device (SW2) 14), which are network relay devices, and a plurality of counter devices (a first counter device 16 and a second counter device 18). That is, the communication system 10 includes the counter devices 16 and 18 forming a pair and a plurality of network relay devices (the switch devices 12 and 14) connecting the counter devices 16 and 18.
In this embodiment, a case in which frames are transmitted from the first counter device 16 to the second counter device 18 as indicated by arrows in
Each of the switch devices 12 and 14 includes two reception ports RP connected to the first counter device 16 and two transmission ports SP connected to the second counter device 18. That is, each of the switch devices 12 and 14 includes reception ports RP1 and RP2 and transmission ports SP1 and SP2. Each of the switch devices 12 and 14 includes a bridge port BP connected to the other switch.
That is, each of the network relay devices (the switch devices 12 and 14) includes a plurality of communication ports (the reception ports RP1 and RP2 and the transmission ports SP1 and SP2) provided for each of the counter devices 16 and 18 and connecting the own network relay device (hereinafter referred to as “own device”) and the counter devices 16 and 18 and the bridge port BP connected to the other network relay device.
Note that, in this embodiment, in order to examine a case in which frames are transmitted from the first counter device 16 to the second counter device 18, ports connected to the first counter device 16 in the switch devices 12 and 14 are referred to as “transmission ports” and ports connected to the second counter device 18 in the switch devices 12 and 14 are referred to as “reception ports”. However, when frames are transmitted from the second counter device 18 to the first counter device 16, the ports connected to the second counter device 18 in the switch devices 12 and 14 function as the “transmission ports” and the ports connected to the first counter device 16 in the switch devices 12 and 14 function as the “reception ports”.
Each of the counter devices 16 and 18 includes two ports connected to the first switch device 12 and two ports connected to the second switch device 14. That is, each of the counter devices 16 and 18 includes four ports in total including ports P1 and P2 connected to the first switch device 12 and ports P3 and P4 connected to the second switch device 14.
In a logical connection configuration of the communication system 10, the ports P1 to P4 of the first counter device 16 are virtually regarded as one port (LAG1) by applying a link-aggregation function to the ports P1 to P4 and the ports P1 to P4 of the second counter device 18 are virtually regarded as one port (LAG2) by applying the link-aggregation function to the ports P1 to P4. The reception ports RP1 and RP2 of the first switch device 12 and the reception ports RP1 and RP2 of the second switch device 14 are virtually regarded as one port of one device (MC-LAG1) by applying a multi-chassis link-aggregation function to the reception ports RP1 and RP2 and the transmission ports SP1 and SP2 of the first switch device 12 and the transmission ports SP1 and SP2 of the second switch device 14 are virtually regarded as one port of one device (MC-LAG2) by applying the multi-chassis link-aggregation function to the transmission ports SP1 and SP2.
In
A frame transmitted from the third port P3 of the first counter device 16 is received by the reception port RP1 of the second switch device 14 and transmitted from the transmission port SP1 or the transmission port SP2 (in
It is determined according to traffic amounts of the ports at every time which transmission ports are used when frames are transmitted from the switch devices 12 and 14 to the counter devices.
Note that, although not shown, the switch devices 12 and 14 may further include pluralities of ports and three or more counter devices may be connected to the switch devices 12 and 14. In this embodiment, as shown in, for example, lower parts of
This embodiment is also applicable to a case in which the number of counter devices on a transmission side and the number of counter devices on a reception side are different and a case in which the number of ports of the counter device on the transmission side and the number of ports of the counter device on the reception side are different as shown in
Subsequently, a functional configuration of the switch devices 12 and 14 is explained.
The first switch device 12 includes a switch unit 120 and a monitor control unit 122 besides the reception ports RP1, RP2, . . . , the transmission ports SP1, SP2, . . . , and the bridge port BP connected to the other switch device (in
Note that, in the following explanation, it is assumed that the first switch device 12 includes two reception ports RP1 and RP2 and includes two transmission ports SP1 and SP2.
The switch unit 120 is specifically an ASIC (Application Specific Integrated Circuit) 606 (see FIG. 8). Frames received by the reception ports RP1 and RP2 are transmitted from one of the transmission ports SP1 and SP2.
The monitor control unit 122 monitors and controls a transfer state of the frames in the switch unit 120.
The monitor control unit 122 includes a traffic totalization unit 124, a failure detection unit 126, an other-device-information acquisition unit 128, a state management database (DB) 130, a traffic bypass unit 132, and a bypass-traffic process unit 134.
The traffic totalization unit 124 totalizes, for each of multi-chassis link-aggregation groups set for the communication ports of the own device, a traffic amount received by the communication ports.
Specifically, the traffic totalization unit 124 totalizes, as a total traffic amount of MC-LAG1, a sum of a traffic amount received by the reception port RP1 in a predetermined period and a traffic amount received by the reception port RP2 in the predetermined period.
The traffic totalization unit 124 records the totalized traffic amounts of the multi-chassis link-aggregation groups in the state management database 130 explained below.
The failure detection unit 126 detects whether communication ports of the own device to be transmission destinations of traffic of the multi-chassis link-aggregation group are effective.
For example, when the traffic can be normally transmitted from the transmission ports SP1 and SP2 of the own device, which are transmission destinations of MC-LAG1, the failure detection unit 126 determines that the transmission ports SP1 and SP2 are effective (have no failure). On the other hand, when the traffic cannot be normally transmitted from the transmission port SP1 or SP2 of the own device, the failure detection unit 126 determines that the transmission port SP1 or SP2 is not effective (is out of order).
Note that a failure of the transmission port SP in this embodiment indicates a state in which transmission of traffic from the transmission port SP cannot be normally performed and includes, for example, besides a failure of the transmission port SP itself, a failure of the communication ports of the counter devices 16 and 18 and a failure of a connection line between the communication ports.
The failure detection unit 126 records presence or absence of a failure of each of the communication ports of the own device (whether the communication port is effective) in the state management database 130 explained below.
The other-device-information acquisition unit 128 acquires a traffic amount for each of the multi-chassis link-aggregation groups in the other network relay device, in this embodiment, the second switch device 14 and information concerning whether the communication ports of the second switch device 14 are effective.
The other-device-information acquisition unit 128 acquires a total traffic amount for each of the multi-chassis link-aggregation groups and an operation state of the communication ports in the second switch device 14 from the traffic totalization unit 124 and the failure detection unit 126 (both of which are not shown) of the second switch device 14 via, for example, the bridge port BP.
Alternatively, the other-device-information acquisition unit 128 may read out a traffic amount for each of link-aggregation groups in the second switch device 14 and presence or absence of a failure on a link from, for example, the state management database 130 of the second switch device 14.
The other-device-information acquisition unit 128 records acquired information concerning the second switch device 14 in the state management database 130 explained below.
The state management database 130 stores the traffic amount totalized by the traffic totalization unit 124, the presence or absence of a failure detected by the failure detection unit 126, the information concerning the second switch device 14 acquired by the other-device-information acquisition unit 128, and the like.
The state management database 130 shown in
In the identifier 1301 of the multi-chassis link-aggregation group, identifiers for identifying multi-chassis link-aggregation groups set for the communication ports of the switch devices 12 and 14 are recorded. In this embodiment, in order to examine traffic transmitted from the first counter device 16 to the second counter device 18, in
In
In the device identifier 1302, “SW1” is stored as an identifier of the first switch device 12 and “SW2” is stored as an identifier of the second switch device 14.
In the transmission destination port number 1303, an identifier (a port number) of a communication port to be a transmission destination of traffic of the multi-chassis link-aggregation group indicated by the identifier 1301 is stored.
In
In the operation state information 1304, an operation state (presence or absence of a failure) of the communication port identified by the transmission destination port number 1303 is recorded.
In the example shown in
In the following explanation, a transmission port in which a failure is detected is referred to as “failure communication port” and a transmission port in which a failure is not detected is referred to as “effective communication port”.
In the traffic amount information 1305, a traffic amount in a predetermined period for each of the link-aggregation groups totalized by the traffic totalization unit 124 is recorded.
In the example shown in
In the apportion ratio information 1306, an apportion ratio for traffic to the other relay device (the second switch device 14) calculated by the traffic bypass unit 132 explained below is recorded.
Referring back to
Such unbalance of the traffic occurs, for example, when there is a counter device connected to only one of the switch devices 12 and 14 besides when there is a failure of the communication port.
For example, when numerical values shown in
Accordingly, the traffic amount per effective communication port in the first switch device 12 is a double of the traffic amount per effective communication port in the second switch device 14. It is seen that the first switch device 12 is in a state in which congestion easily occurs.
In this embodiment, the traffic bypass unit 132 calculates an apportion ratio for traffic such that traffic amounts per effective communication port in the switch devices 12 and 14 become uniform.
The apportion ratio is calculated by, for example, the following Expression (1). Note that, in the expression, “MC-LAG” indicates a multi-chassis link-aggregation group and “SW” indicates a switch device.
Apportion ratio={(total traffic amount of MC-LAG+number of effective ports of entire MC-LAG)×number of effective ports of SW−traffic amount of SW}÷total traffic amount of MC-LAG (1)
An apportion ratio is calculated as follows with reference to the numerical values shown in
Apportion ratio from the first switch device 12={(12÷3)×1−6}÷12=−1/6(≈−16%)
Apportion ratio from the second switch device 14={(12÷3)×2−6}÷12=1/6(≈+16%)
The negative apportion ratio indicates that a traffic amount of the own device is larger than a traffic amount of the other device and indicates that a traffic amount per effective communication port can be made uniform by bypassing traffic corresponding to the apportion ratio to the other device (subtracting the traffic). The positive apportion ratio indicates that the traffic amount of the own device is smaller than the traffic amount of the other device and indicates that the traffic amount per effective communication port can be made uniform by receiving traffic corresponding to the apportion ratio from the other device (adding the traffic).
Accordingly, in the example explained above, the traffic amount per effective communication port can be made uniform by bypassing the traffic from the first switch device 12 to the second switch device 14 by approximately 16%.
That is, the traffic bypass unit 132 calculates a traffic distribution amount per effective communication port by dividing a traffic total amount in the same link-aggregation group by a total number of effective communication ports in the link-aggregation group. The traffic bypass unit 132 then determines a traffic amount transmitted to the other network relay device (the second switch device 14) by dividing a difference between a traffic amount obtained by multiplying together the traffic distribution amount and the number of effective communication ports of the own device and an actual traffic amount in the own device by the traffic total amount.
Note that, if the difference between the traffic amount per effective communication port in the own device and the traffic amount per effective communication port in the other network relay device (the second switch device 14) is small, since an effect of bypassing is low (a congestion state is unlikely), the bypassing of the traffic may not be performed.
In this embodiment, a threshold is set for the absolute value of the apportion ratio. The bypassing is not performed, for example, when the absolute value of the apportion ratio is smaller than 10%. For example, in MC-LAG3 shown in
Note that the threshold may be set to “0%” or the like and the bypassing to the other device may always be performed when unbalance of the traffic occurs.
The traffic bypass unit 132 gives, to traffic transmitted to the other relay device (the second switch device 14) via the bridge port BP (hereinafter referred to as “bypass traffic”), an identifier of a multi-chassis link-aggregation group set for a communication port that receives the traffic (hereinafter referred to as “reception group identifier”). For example, a reception group identifier of traffic received by the reception port RP1 or RP2 of the first switch device 12 is “MC-LAG1”.
This is to specify a transmission destination of the bypass traffic on the second switch device 14 side that receives the bypass traffic from the first switch device 12. Note that the bypass traffic transmitted from the traffic bypass unit 132 of the first switch device 12 is processed by the bypass-traffic process unit 134 on the second switch device 14 side.
In a frame 300 to be the bypass traffic, a reception group identifier 301, which is an identifier of a multi-chassis link-aggregation group set for the reception port RP when the frame is received by the first switch device 12, is given to the head of the header portion.
A header of original traffic includes a MAC address (a destination MAC address) 302 of a device to be a transmission destination of a frame and a MAC address (a transmission source MAC address) 303 of a device at a transmission source.
Referring back to
The bypass-traffic process unit 134 transmits the traffic to a communication port other than a communication port in which a link-aggregation group specified by a reception group identifier attached to the traffic is set. When transmitting bypass traffic, the bypass-traffic process unit 134 removes the reception group identifier 301 (see
For example, a case in which a link connected to the transmission port SP1 of the first switch device 12 is out of order as shown in
The bypass-traffic process unit 134 of the second switch device 14 selects, based on “MC-LAG1” attached to the header of the received bypass traffic, a communication port set as a transmission destination of the frame.
Specifically, the bypass-traffic process unit 134 transmits the bypass traffic from a port other than the reception ports RP (RP1 and RP2) of the own device (the second switch device 14) in which “MC-LAG1” is set, that is, the transmission port SP1 or SP2 to the second counter device 18.
Subsequently, a processing flow of the switch devices 12 and 14 is explained. A flowchart referred to below is explained with reference to a processing flow of traffic received by the first switch device 12 from the first counter device 16 as an example.
The traffic totalization unit 124 of the first switch device 12 totalizes a total traffic amount received by the multi-chassis link-aggregation group set for the own device and updates the traffic amount information 1305 (see
The failure detection unit 126 detects a state (effective or failure) of each of communication ports of the own device and updates the operation state information 1304 of the state management database 130 (step S101).
The other-device-information acquisition unit 128 acquires a total traffic amount for each of the multi-chassis link-aggregation groups and an operation state of the communication ports of the second switch device 14 (the other device) and updates the traffic amount information 1305 and the operation state information 1304 (fields of the second switch device 14) of the state management database 130 (step S102).
When receiving an acquisition request for the total traffic amount for each of the multi-chassis link-aggregate groups and the operation state of the communication ports from the other-device-information acquisition unit 128 of the second switch device 14, the first switch device 12 transmits the relevant information to the second switch device 14 (step S103).
Subsequently, the traffic bypass unit 132 calculates an apportion ratio for traffic using the information of the state management database 130 (step S104).
The traffic bypass unit 132 compares a transmission traffic amount per effective communication port (in
When the transmission traffic amount per effective communication port in the own device is equal to or smaller than the transmission traffic amount per effective communication port in the second switch device 14 (step S105: No), since it is unnecessary to bypass the traffic from the own device, the first switch device 12 ends the processing of this flowchart.
On the other hand, when the transmission traffic amount per effective communication port in the own device is larger than the transmission traffic amount per effective communication port in the second switch device 14 (step S105: Yes), the traffic bypass unit 132 determines whether the apportion ratio calculated in step S104 is equal to or larger than a threshold (for example, 10%) (step S106).
When the apportion ratio is equal to or larger than the threshold (step S106: Yes), the traffic bypass unit 132 transmits traffic corresponding to the apportion ratio to the second switch device 14 via the bridge port BP (step S107) and ends the processing of this flowchart.
At this time, the traffic bypass unit 132 gives a reception group identifier of the traffic to the header of the bypass traffic.
On the other hand, when the apportion ratio is smaller than the threshold (step S106: No), since an effect is small even if the traffic is bypassed, bypassing of the traffic is not performed. The first switch device 12 directly ends the processing of this flowchart.
Subsequently, processing on a switch device side that receives bypass traffic is explained.
The bypass-traffic process unit 134 of the second switch device 14 receives bypass traffic from the first switch device 12 via the bridge port BP (step S200).
Subsequently, the bypass-traffic process unit 134 detects a reception group identifier given to a header of the bypass traffic (step S201) and selects a port set as a transmission destination of the bypass traffic (a transmission destination port) from communication ports other than a communication port in which a multi-chassis link-aggregation group identified by the reception group identifier is set (step S202).
The bypass-traffic process unit 134 deletes the reception group identifier given to the header of the bypass traffic (step S203) and, then, transmits the bypass traffic from the transmission destination port selected in step S202 (step S204) and ends the processing of this flowchart.
<Hardware Configuration>
Subsequently, a hardware configuration of the switch devices 12 and 14, which are the network relay devices, is explained.
The switch devices 12 and 14 according to this embodiment are realized by, for example, a switch device 600 having a configuration shown in
The CPU 601 operates based on a program stored in the ROM 602 or the HDD 604. The ROM 602 stores a boot program to be executed by the CPU 601 at a start time of the switch device 600, a program relating to hardware of the switch device 600, and the like.
The HDD 604 stores a program to be executed by the CPU 601 and data and the like used by the program.
The ports 605 include the reception port RP, the transmission port SP, and the bridge port BP explained above. Communication lines for transmitting and receiving data to and from the other devices (for example, counter devices) are connected to the ports 605.
The ASIC 606 realizes transfer of data between any ports.
For example, when the switch device 600 functions as the switch devices 12 and 14 of the present invention, the CPU 601 of the switch device 600 realizes the functions of the switch devices 12 and 14 by executing a program loaded onto the RAM 603. Data in the RAM 603 is stored in the HDD 604. The CPU 601 reads a program relating to target processing from the ROM 602 or the HDD 604 and executes the program.
<Effects>
Effects of the communication system according to the present invention is explained below.
The communication system according to the present invention is the communication system 10 including the counter devices 16 and 18 forming a pair and the plurality of network relay devices (the switch devices 12 and 14) connecting the counter devices 16 and 18. Each of the switch devices 12 and 14 includes the plurality of communication ports (the reception ports RP1 and RP2 and the transmission ports SP1 and SP2) provided for each of the counter devices 16 and 18 and connecting the own device (the own switch device) and the counter devices 16 and 18, the bridge port BP connected to the other switch device, the traffic totalization unit 124 that totalizes, for each of the multi-chassis link-aggregation groups set for the communication ports, a traffic amount received by the communication ports of the own device, the failure detection unit 126 that detects whether the communication port of the own device to be a transmission destination of traffic of the multi-chassis link-aggregation group is effective, the other-device-information acquisition unit 128 that acquires a traffic amount for each of the multi-chassis link-aggregation groups in the other switch device and information concerning whether the communication port of the other switch device is effective, and the traffic bypass unit 132 that transmits a part of the traffic of the multi-chassis link-aggregation group to the other switch device via the bridge port BP when a traffic amount per effective communication port in the own device is larger than a traffic amount per effective communication port in the other switch device by the threshold or more in the multi-chassis link-aggregation group.
In this way, the network relay devices (the switch devices 12 and 14) compare, about the traffic in the multi-chassis link-aggregation group, the traffic amount per effective communication port in the own device and the traffic amount per effective communication port in the other switch device and, when the traffic amount of the own device is larger by the threshold or more, bypasses a part of the traffic to the other switch device via the bridge port BP.
Accordingly, for example, when a part of the communication ports of the switch devices 12 and 14 fails, it is possible to avoid traffic concentrating on the communication port without a failure of the switch device and suppress occurrence of congestion. For example, when the counter device connected to only one of the switch devices 12 and 14 is present as shown in
The switch devices 12 and 14 do not perform bypassing of the traffic when the difference between the traffic amounts of the own device and the other switch device is small (equal to or smaller than the threshold). Therefore, it is possible to avoid unnecessary bypassing (having a limited effect) and improve processing efficiency of the communication system 10.
In the communication system 10, the traffic bypass unit 132 calculates a traffic distribution amount per effective communication port by dividing a traffic total amount in the same multi-chassis link-aggregation group by a total number of the effective communication ports in the multi-chassis link-aggregation group and determines a traffic amount transmitted to the other switch device by dividing a difference between a traffic amount obtained by multiplying together the traffic distribution amount and the number of effective communication ports of the own device and an actual traffic amount in the own device by the traffic total amount.
Consequently, the network relay devices (the switch devices 12 and 14) can make uniform transmission traffic amounts from the communication ports in which the same multi-chassis link-aggregation group is set and more surely prevent congestion.
In the communication system 10, each of the switch devices 12 and 14 further includes the bypass-traffic process unit 134 that transmits, when receiving traffic from the other switch device via the bridge port BP, the traffic from the communication port of the own device connected to the counter device to be a transmission destination of the traffic. The traffic bypass unit 132 gives, to the traffic to be transmitted, an identifier of the multi-chassis link-aggregation group set for the communication port that receives the traffic. The bypass-traffic process unit 134 transmits the traffic from the communication port other than the communication port in which the multi-chassis link-aggregation group specified by the identifier is set.
Consequently, it is possible to avoid traffic being returned to a counter device at a transmission source of the traffic (avoid a loop occurring) and improve processing efficiency of the communication system 10.
Note that the present invention is not limited to the embodiment explained above. A lot of modifications are possible by those having ordinary knowledge in the field within the technical idea of the present invention.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/007984 | 2/27/2020 | WO |
