WO2018030562A1 - Seamless frame transmission method for ethernet switch - Google Patents

Abstract

The present invention relates to a seamless frame transmission method for an Ethernet switch, comprising the steps of: allowing an Ethernet switch to generate a pointer for a frame transmitted from a transmission node of a trunk port connected to the Ethernet switch; allowing the Ethernet switch to generate a pointer value, having increased more than a point generated in the aforementioned step, for a new frame transmitted from the transmission node; allowing the Ethernet switch to receive a pointer and determine whether a reception node, which is a destination of a frame for the pointer, has been connected to the Ethernet switch; allowing the Ethernet switch to forward the frame to the reception node according to the determination that the reception node, which is the destination of the frame, is connected to the Ethernet switch; deleting a duplicated frame having the same pointer value as the frame; and allowing the Ethernet switch to flood the frame, by using a switch connected to the Ethernet switch, according to the determination that the reception node, which is the destination of the frame, is not connected to the Ethernet switch. Therefore, even when a malfunction occurs during transmission of a frame, a switch connected to a reception node delivers the frame to the reception node, which is the destination, and thus the reliability of delivery of the frame to the destination is guaranteed.

Description

How to Send Frameless Frames on an Ethernet Switch

The present invention relates to a frame transmission method in which an Ethernet switch is seamless, that is, a failure recovery time is zero.

The high-availability seamless redundancy or ring (HSR) protocol relates to a high availability automation network, and a technique for converting a single network transmission line into a pair has been proposed to prevent a system failure caused by a single defect.

However, the HSR protocol has a limitation in that the network configuration is expensive because the Ethernet device used must be changed to a device capable of using the HSR protocol.

Accordingly, it is necessary to implement a high availability network using Ethernet equipment currently in use.

[Preceding technical literature]

[Patent Documents]

(Patent Document 1) Korean Registered Patent Publication No. 1397299

An object of the present invention is to provide a seamless Ethernet, that is, a seamless frame transmission method of an Ethernet switch for implementing an Ethernet network system so that a recovery time when a failure occurs is close to zero.

In a seamless frame transmission method of an Ethernet switch according to an embodiment of the present invention, in a network structure including a transmitting node, an Ethernet switch, and a receiving node, in a seamless frame transmission method of an Ethernet switch, (a) the Ethernet switch itself Generating a pointer to a frame transmitted from a transmitting node of a trunk port connected to the terminal (S100); (b) generating, by the Ethernet switch, a pointer value that is increased from a point generated in step (a) for a new frame transmitted from the transmitting node (S200); (c) receiving, by the Ethernet switch, a pointer generated from steps (a) and (b) and determining whether a receiving node, which is a destination of a frame for the pointer, is connected to itself (Q100); (d-1) forwarding the frame to the receiving node in step (c) when the Ethernet switch determines that the receiving node that is the destination of the frame is connected to the receiving node (S310); (d-2) deleting a duplicate frame having the same pointer value as the frame on which the step (d-1) is performed; And (e) flooding the frame with the switch connected to the Ethernet switch (S330) when the Ethernet switch determines that the receiving node, which is the destination of the frame, is not connected to itself in step (c). do.

Step (a) (S100) is characterized by generating a pointer for each frame transmitted from at least one transmitting node connected to the Ethernet switch.

Steps (a) and (b) are performed by storing the pointer value generated for the frame by the Ethernet switch in the storage space of the Ethernet switch in correspondence with the frame.

In the step (a), the Ethernet switch generates a pointer value of 1 for the frame transmitted from the transmitting node, and in step (b), the Ethernet switch transmits the Ethernet switch from the transmitting node. For a new frame, it is performed by generating a pointer value which is increased by 1 from the point generated in the step (a).

According to this aspect, in the method of transmitting a seamless frame of an Ethernet switch according to an embodiment of the present invention, a switch connected to a transmitting node generates a pointer to a frame transmitted from each transmitting node, and the switch transmits from the same transmitting node. It is created by incrementing the pointer to a new frame, and the switch including the destination node of the frame transmitted from the transmitting node as the receiving node compares the reception time of the frame having the same pointer value and deletes the frame copy or makes the frame copy the destination node. And forwarding or flooding to an incoming receiving node.

Accordingly, in a network structure having a switch according to the present invention, even if a failure occurs during transmission of a frame, the frame is transmitted to the receiving node by a structure in which the frame is transmitted through another path between the switches connected between the transmitting node and the receiving node. The connected switch delivers the frame to the destination receiving node, which ensures the destination delivery reliability of the frame.

At this time, when a failure occurs on a network that transmits frames, unlike the RSTP protocol, which requires a specific time to find an alternative path to the target switch, the recovery time is zero (zero recovery time), so the delay can be reduced. There is an effect that can improve the transmission efficiency of the.

1 is a diagram schematically illustrating a frame transmission and reception of a node in a network structure to which a method for transmitting a seamless frame of an Ethernet switch according to an embodiment of the present invention.

2 is a flowchart illustrating a method of transmitting a frameless frame of an Ethernet switch according to an embodiment of the present invention.

3 is a graph illustrating a comparison of traffic reduction amounts of a network to which a seamless frame transmission method of an Ethernet switch according to an embodiment of the present invention is compared with a network to which a conventional HSR protocol having a seamless frame transmission function is applied.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Next, a seamless frame transmission method of an Ethernet switch according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, referring to FIG. 1, the network structure to which the seamless frame transmission method of the Ethernet switch according to the exemplary embodiment of the present invention is described in detail will be described. ), A second switch 12, a third switch 13, a fourth switch 14, a transmitting node 21, and a receiving node 22.

In this case, the first to fourth switches 11, 12, 13, and 14 are Ethernet switches, which receive frames from nodes directly connected to the switches, and transfer them to other switches through a link.

The first to fourth switches 11, 12, 13, and 14 have a MAC address table storing a MAC address table of a node directly connected to the switch, and the destination address of the received frame is a MAC. It is determined whether it exists in the address table, and the frame is transmitted to a node directly connected to the switch, or the frame is flooded (meaning flooding, flooding, and in the following specification, the word flood is used interchangeably with flooding).

Among these switches, the first switch 11 is directly connected to the note X which is the transmitting node 21. The first switch 11 receives a frame from the transmitting node directly connected to each switch, and generates a pointer to the corresponding frame. Then, the generated pointer is stored corresponding to the frame.

The pointer generated for the frame may be used as an identifier for identifying the frame.

At this time, the pointer value for the frame transmitted from the transmitting node directly connected to the switch is preferably stored in each switch.

When each switch stores a pointer value for a frame transmitted by a transmitting node, if the switch receives a new frame different from the frame that already stores the pointer value from the transmitting node, the pointer value for the newly received frame. Is stored by increasing the value of the pointer already stored.

In one example, when the switch receives a new frame from the transmitting node and increases the pointer value, the switch may increase the pointer value by one than the previously stored pointer value to generate the pointer value and store the corresponding pointer value.

For example, when the first switch 11 of FIG. 1 receives a specific frame from the node X which is the transmitting node 21, the first switch 11 sets the pointer value of the corresponding frame to 1 to correspond to the frame. If the frame received from the node X is a different frame from the stored frame, the pointer value is increased by 1 and set to 2 to correspond to the newly received frame.

In this way, the switch directly connected to the transmitting node generates a pointer value for the frame received from the transmitting node, and stores the pointer value and the frame corresponding to the generated pointer. When a new frame is received, the switch increases and generates a pointer value. A pointer value for the frames is generated and stored by storing the frames corresponding to the frames.

In this case, the operation of determining whether the frame received from the transmitting node is a newly received frame, that is, whether the frame has already been received is a part of storing the pointer value and the frame in correspondence with the pointer value when the switch receives the frame. By searching for.

In this case, when the switch receives the first frame from the transmitting node, it sets the pointer value to 1.

Also, in one example, when the switch receives a frame from each of two different transmitting nodes, the switch sets a frame for the transmitting node.

In a more detailed example, if two different sending nodes are connected to a switch and two different frames are received from one transmitting node, pointer values are set to 1 and 2, respectively, for the two frames received from that transmitting node. It is set as, and it corresponds to each frame and stored according to the corresponding transmission node.

However, in this case, when the switch receives one frame from another transmitting node, the switch sets the pointer value to 1 for the frame received from the other transmitting node and stores the pointer value in association with the frame and the transmitting node.

As such, the switch sets a pointer value for each transmitting node when receiving a frame from a different transmitting node.

As such, the first switch 11 connected to the transmitting node generates a pointer for the frame received from the connected transmitting node, increases the pointer value for the new frame received from the same transmitting node, and generates another pointer for the other transmitting node. By assigning a new pointer value, it is possible to efficiently manage the information of the frames transmitted from the transmission nodes connected to the first switch (11).

The first switch 11 forwards or floods the frames received from the transmitting node to the second and fourth switches 12 and 14, respectively.

In this case, when the first switch 11 forwards or floods the frames to the second and fourth switches 12 and 14, the first and second switches 11 together with the pointer values generated for the frames received from the transmitting node 21 are combined together. 4 switches (12, 14).

In addition, the second and fourth switches 12 and 14 store the frames received from the first switch 11 and pointer values thereof in their storage spaces, and the nodes of the received frames are nodes connected to the destination. In this case, for example, the destination of the frame transmitted from the transmitting node 21 and transmitted to the second or fourth switch 12, 14 through the first switch 11 is the second or fourth switch 12, 14. In the case of a node connected to the node 1), the second or fourth switches 12 and 14 transmit the corresponding frame to the corresponding node as the destination.

However, in the network structure according to the example of FIG. 1, since the second and fourth switches 12 and 14 are not connected to the node as the destination, the third switch 13 receives the frame received from the first switch 11. Flood with.

The third switch 13 receives frames received from the second and fourth switches 12 and 14 and pointer values thereof, and stores them in its storage space, and the destination of the received frames is connected to the third switch 13. In the case of a node, the frame is forwarded to the destination node.

In this case, in order to determine whether the destination of the frames received from the second and fourth switches 12 and 14 is the node connected to the third switch 13, the third switch 13 may check the MAC of the nodes connected to the third switch 13. The address must be stored as a MAC address table, and this is determined by searching the MAC address table for the MAC address of the destination included in the frame.

In one example, the third switch 13 receives the same frame with the same pointer value from the second switch 12 and the fourth switch 14 respectively, and the destination of the frame is connected to the third switch 13. In the case of a node, the third switch 13 transfers the first frame received in time to the receiving node 22 which is the destination of the frame, and deletes the remaining frames.

However, at this time, the third switch 13 receives the pointer value and the corresponding frame from the second and fourth switches 12 and 14, and the MAC address of the receiving node 22 which is the destination of the frame is its MAC address. If not present in the table, the third switch 13 adds the MAC address of the receiving node 22 to its MAC address table.

More specifically, when the frame transmitted by a switch that is not connected to another switch such as the third switch 13 and is connected only to nodes includes a MAC address of a destination node as a destination, the third switch 13 Adds the MAC address of the receiving node to its MAC address table.

In this way, even if the third switch 13 connected to the destination of the frame receives the same frame having the same pointer value through different paths, the first received frame is transmitted to the destination node, and the later received frame is deleted. In addition, the frame can be transmitted to the receiving node through various paths, and the unloaded frame can be deleted to prevent looping in the network, thereby reducing the load on the network.

More specifically, even if a network failure occurs between the fourth switch 14 and the third switch 13 when a frame transmitted from the transmitting node 21 is delivered to the receiving node 22, the transmitting node 21 transmits. One frame is transferred to the receiving node 22 as a destination through a path passing through the second switch 12 and the third switch 13 to have a network structure with a recovery time of zero.

In addition, the total network traffic in the network structure having the structure as shown in FIG. 1 is calculated from the following Equation 1, which is significantly smaller than the total network traffic in the case of applying the existing HSR protocol calculated from the following Equation 2. Have

[Equation 1]

[Equation 2]

Taking the network having the structure of FIG. 1 as an example, Equation 1 and Equation 2 will be described in more detail. The total number of links on the network is L, the number of frames transmitted from node i is F, and the node can transmit at the same time. When the number of existing frames is N, in the network structure of FIG. 1, it is assumed that L is 4 and F is 1, where N is 1.

In the above case, the total network traffic amount according to the present invention calculated from Equation 1 is 5, while the total network traffic amount using the conventional HSR protocol calculated from Equation 2 is 8, so that the present invention is applied. In this case, the number of frames can be significantly reduced to reduce the amount of traffic in the network.

In this case, the Roundup () function of Equation 1 is a function of rounding up the calculated value when the calculated value is less than or equal to the decimal point.In the case where the number of links constituting the network is odd, Equation 1 above is applied. If the number of links constituting the network is even, the following equation 3 may be applied to calculate the total traffic volume of the network.

[Equation 3]

At this time, the total traffic amount in the network to which the present invention is applied to the total traffic amount in the network to which the HSR protocol is applied may be calculated as a traffic reduction percentage (RP) as shown in Equation 4 below, which is a graph of FIG. 3. It may be shown as.

[Equation 4]

In the network having the structure of FIG. 1, the traffic reduction rate calculated from Equation 4 above is 37.5 (unit:%), and as shown in graph 3, as the number of nodes increases, the reduction rate approaches 50%.

Next, a seamless frame transmission method of the Ethernet switch according to an embodiment of the present invention will be described with reference to the flowchart of FIG. 2.

The seamless frame transmission method of the Ethernet switch according to an embodiment of the present invention may be performed through the network structure described above with reference to FIG. 1, and the network structure of FIG. 1 will be described below with reference to FIG. 2. This will be described.

In the seamless frame transmission method of the Ethernet switch of the present invention, the step of generating a pointer for each frame transmitted from the transmitting node of the trunk port connected to all the switch (S100), by increasing the pointer when transmitting a new frame at the transmitting node Generating step (S200), determining whether the receiving node which is the destination of the received frame is connected to itself (Q100), forwarding the frame to the receiving node (S310), deleting the same frame having the same pointer value Step S320, and flooding the received frame (S330) is made.

These processes are the switches and the transmitting node 21 directly connected to the transmitting node 21 or the receiving node 22, such as the first to fourth switches (11, 12, 13, 14) of the network structure shown in FIG. All of them may be performed in a switch that serves as a link for receiving a frame from the frame and delivering the frame to the receiving node 22.

First, the step of generating a pointer for each frame transmitted from the transmitting node of the trunk port connected to all the switches (S100) is a step of generating a pointer to the frame transmitted to the transmitting node directly connected to the switch, the first switch ( 11) generates a pointer for every frame transmitted from the transmitting node 21 connected to the switch through the trunk port, and stores the generated pointer in correspondence with the frame.

In this step S100, all the switches generate pointers to the frames transmitted by all transmitting nodes connected thereto.

Then, in the step S200 of generating a pointer when transmitting a new frame in the transmitting node, the first switch 11 receives a new frame different from the frame already received and stored from the transmitting node 21. In this case, the first switch 11 generates a pointer value which is increased by 1 from the pointer value generated and stored for the frame received from the transmission node 21 and stores the pointer value for the new frame.

Next, the first switch 11 determines whether the receiving node 22, which is the destination of the frame received from the transmitting node 21, is connected to its switch (Q100), and the MAC of the first switch 11 has This is performed by checking whether the MAC address of the destination node of the frame received from the transmitting node 21 is included in the address table.

In this case, in the case of a switch connected to the second switch 12 and the fourth switch 14 without being connected to a node like the first switch 11, the first switch 11 may set the pointer value set for the frame. Flooding (S330) to the second switch 12 and the fourth switch (14).

In this step (S330), when the first switch 11 receives a frame from a plurality of transmitting nodes and sets the pointer value, the first switch 11 transmits the transmitting node, the frame, and the pointer value in the first step (S100). Respectively store and correspond to the second switch 12 and the fourth switch 14 in the above step (S330).

The switches continue to perform the step S330 when a node is not connected to the switch.

In this case, as in the third switch 13, when the node is connected to the switch, the third switch 13 determines that the receiving node 22 which is the destination of the frame is connected to the switch from the above step Q100. In this case, the MAC address of the receiving node which is the destination of the frame is searched in the MAC address table of the third switch 13.

In one example, the receiving node 22, which is the destination of the same frame transmitted from the transmitting node 21 and received through the first and second switches 11 and 12 or the first and fourth switches 11 and 14, may be used. If the MAC address exists in the MAC address table of the third switch 13, the third switch 13 forwards the frame to the receiving node 22 (S310) and the same frame having the same pointer value. The step S320 is performed.

At this time, in the step S320 in which the third switch 13 deletes the same frame having the same pointer value, the third switch 13 is located in the same frame having the same pointer value received and stored through different paths. For the first time, the received frame is transmitted to the receiving node 22, and the received frame is deleted later.

At this time, in this step Q100, the nodes to be forwarded to the third switch 13 are not connected and only nodes are connected. However, the MAC of the receiving node that is the destination of the MAC address table included in the frame is included in the frame. If it does not contain an address, the MAC address of the destination node of the frame is added to the MAC address table.

As such, the frame transmitted from the transmitting node 21 is transmitted to the receiving node 22 by a plurality of paths by the first to fourth switches 11, 12, 13, and 14, and the third switch 13. Even if the same frame is received in duplicate, the third switch 13 can improve network efficiency by eliminating redundancy by determining the duplicated frame using the pointer value generated by the first switch 11.

In addition, since the frame transmitted from the transmitting node 21 is transmitted to the receiving node 22 through a plurality of paths, even if a failure occurs in the network, it does not require a recovery time required to generate an alternative path like the RSTP protocol. Therefore, it can provide a network with 0 recovery time in case of network failure.

In addition, to apply the HSR protocol, it is possible to reduce the cost of changing the existing network equipment into a device to which the HSR protocol is applicable.

In addition, this method can improve the frame transfer efficiency without performing a frame change such as adding bytes to an existing frame, and thus can be applied to all network topologies, thereby providing high availability.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

[Description of the code]

11: first switch 12: second switch

13: 3rd switch 14: 4th switch

21: transmitting node 22: receiving node

Claims (4)

In a seamless frame transmission method of an Ethernet switch in a network structure including a transmitting node, an Ethernet switch, and a receiving node, (A) generating a pointer to a frame transmitted from the transmitting node of the trunk port connected to the Ethernet switch (S100); (b) generating, by the Ethernet switch, a pointer value that is increased from a point generated in step (a) for a new frame transmitted from the transmitting node (S200); (c) receiving, by the Ethernet switch, a pointer generated from steps (a) and (b) and determining whether a receiving node, which is a destination of a frame for the pointer, is connected to itself (Q100); (d-1) forwarding the frame to the receiving node in step (c) when the Ethernet switch determines that the receiving node that is the destination of the frame is connected to the receiving node (S310); (d-2) deleting a duplicate frame having the same pointer value as the frame on which the step (d-1) is performed; And (e) flooding the frame with the switch connected to the Ethernet switch, in step (c), when the Ethernet switch determines that the receiving node that is the destination of the frame is not connected to the frame; Seamless frame transmission method of the Ethernet switch is performed, including. The method of claim 1, Step (a) (S100) is a seamless frame transmission method of the Ethernet switch, characterized in that for generating a pointer for each frame transmitted from at least one transmitting node connected to the Ethernet switch. The method of claim 1, Steps (a) and (b) are performed by storing the pointer value generated for the frame by the Ethernet switch in the storage space of the Ethernet switch in correspondence with the frame. How to Send Clause Frames. The method of claim 3, In the step (a), the Ethernet switch generates a pointer value of 1 for the frame transmitted from the transmitting node, Step (b) is performed by the Ethernet switch generating a pointer value increased by 1 from the point generated in step (a) for a new frame transmitted by the Ethernet switch from the transmitting node. Method of transmitting a seamless frame of a switch.

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