KR100870670B1 - Method For Determining a Ring Manager Node - Google Patents

Abstract

The present invention relates to a method for determining a ring manager node that destroys a packet in order to prevent an error in which packet transmission is infinitely repeated in a ring-type Ethernet network.

The present invention relates to a ring manager node setting method according to the prior art, in which a ring manager node is determined to prevent user error that may occur in the setting step and to reduce inefficiency of packet transmission generated by the ring manager node. Provide a method.

The present invention includes nodes having two or more Ethernet ports, the node type of each node included in a ring-type Ethernet network formed through the Ethernet ports, a media access control address, a port number and a hop connected between the nodes. Creates a node information table including the number of HOP), and determines whether there is an even number of master nodes and the total number of nodes from the created node information table, and based on the determination result, hop number and media access control address value between nodes are determined. By comparison, the ring manager node is determined.

Through the ring manager according to the present invention, an infinite loop of packets can be prevented and inefficiencies that can occur during packet transmission and reception can be reduced.

 Ring network, infinite loop, ring manager

Description

Method for Determining a Ring Manager Node}

1 is a view showing a method for destroying a packet using a token according to the prior art.

2 is a view showing a method for destroying a packet using a TTL according to the prior art.

3 is a diagram illustrating a method for setting a blocking node according to the related art.

4A shows a ring manager node according to the present invention.

4B illustrates a node other than the ring manager according to the present invention.

FIG. 5 is a diagram illustrating a position determined as a ring manager node in a network in which one master node and an even number of nodes are even in accordance with the present invention.

FIG. 6 is a diagram illustrating a position determined as a ring manager node in a network in which one master node and an total number of nodes is odd according to the present invention.

FIG. 7 is a diagram illustrating a position determined as a ring manager node in a network having two master nodes and an even number of nodes according to the present invention.

8 is a diagram illustrating a position determined as a ring manager node in a network having two master nodes and an odd number of nodes according to the present invention.

9 is a diagram illustrating a position determined as a ring manager node in a network without a master node according to the present invention.

10 is a diagram illustrating a node information table update and ring manager node determination process according to the present invention.

11 is a flowchart illustrating a ring manager node determination process according to the present invention.

The present invention relates to a method for determining a ring manager node, and more particularly, to a method for determining a ring manager node that destroys a packet to prevent an infinite loop error of the packet in a ring-type Ethernet network.

In the case of configuring a control network by directly connecting communication media (hereinafter referred to as "media") between communication devices (hereinafter referred to as "nodes") that have a built-in switch function and provide two or more Ethernet ports, If an error occurs in the media or intermediate node, the entire network is disconnected.

Since the entire network is disconnected by the control network has a fatal result, in order to ensure reliability, in the control network, a ring-type (ring topology) network capable of communicating with other paths even if an abnormality occurs in a media or intermediate node is used. Aim. In particular, a node providing two or more Ethernet ports with a built-in switch function can forward packets in hardware, so using the node can greatly improve the performance of the network.

However, in the case of a ring-type network using broadcast packets received by all nodes, since the packet is delivered without validating the packet, a loop in which the packet transmission is repeated indefinitely in the network (hereinafter, referred to as an 'infinite loop') is used. May occur.

Conventionally, the following three methods are largely used to prevent the infinite loop from occurring. That is, how to use a token, how to use TTL (Time To Live), and how to set up a ring manager by using a programming and debugging tool (PADT).

The conventional method of using a token is a method in which only a node receiving a frame called a token can transmit data. The conventional method of using TTL is to set a specific field as a TTL field, decrement 1 every time a packet passes through the node, and destroy the packet when its value reaches 0. This method reduces the packet size and retransmits the packet to a port other than the port on which the packet was received. The conventional method for preventing packet forwarding by setting a specific node by a user is one of the most frequently used methods to prevent an infinite loop of packets in a full-duplex communication method. How to set up a node (that is, a blocking node) as a ring manager node.

Hereinafter, a method of preventing an infinite loop of a packet according to the prior art will be described in detail with reference to the accompanying drawings.

1 is a view showing a method for destroying a packet using a token according to the prior art, as shown in the figure, Node 1 occupying the token packet has the authority to use the media, and after a certain time, When passed to node 2, node 2 has permission to use the media. In other words, the token must be occupied before the packet can be transmitted, and the remaining nodes that do not occupy the token are in a standby state. The node that sent the packet destroys the packet when it comes back to itself.

FIG. 2 is a diagram illustrating a method of destroying a packet using a TTL field according to the prior art. As shown in FIG. 2, a TTL field exists for each packet in a dual ring structure, and the TTL field passes through each node. Decreases by 1 every time. If the value of the TTL field of Node 2 decreases by 1 and becomes 0, the packet is no longer delivered from the network and is destroyed. A packet in a ring network is used in the form of attaching a dual ring header (eg, RPR HEADER) to an existing Ethernet frame. The contents of the double ring header are composed of a TTL, a ring number, and the like. Here, the TTL field serves to prevent the packet from repeating indefinitely, and the ring number serves to select a corresponding ring when transmitting the packet.

3 is a view illustrating a user setting a blocking node according to the prior art. As shown in FIG. 3, a user sets node 4 as a blocking node using a PADT. Node 4 releases the packet relay logic so that packets are not relayed.

Methods of using tokens according to the prior art include IEEE802.4 (token bus), IEEE802.5 (token ring), and the like. The biggest feature of the network using the token is that it must have a token in order to transmit a packet to the media or obtain the right to use the media. If you don't have a token, you don't have permission to use media, so you have to wait until the token is given to you. Therefore, it is a method suitable for a bus network structure in which media are physically connected as one, a network using a half duplex communication method, or an Ethernet network based on a switch technology using a full duplex communication method.

The conventional method of using a specific field of a packet as a TTL field is not suitable in a single ring network. The packet format of a dual ring network is currently being standardized and is a packet form of SRP (Spatial Reuse Protocol). Since a packet of a ring network has only an RPR HEADER attached to an existing Ethernet frame, there is a problem in that an RPR HEADER other than a standard Ethernet format needs to be interpreted by modifying an existing Ethernet media access control (MAC) address.

In the conventional method of setting a specific node to prevent packet forwarding, a user needs to select a specific node using a PADT and set it as a ring manager node in order to prevent packet forwarding. In addition, when the module needs to be replaced due to a failure of the communication module, the user setting step is necessary again. If there is a setting error in the user setting step, not only an infinite loop of the packet occurs but also an initial setup time is long. In addition, when transmitting a packet from node 5 to node 3 in FIG. 3, node 4 does not relay the packet, and thus cannot use path 1. Therefore, a packet must be transmitted from node 5 to node 3 using path 2. In particular, when there is a node that blocks transmission and reception of a packet between a master and a slave, that is, a blocking node, in a control network by master-slave communication, there is a case where a long path must be used over a short path as shown in FIG. 3. There is a problem of reducing the efficiency of the network.

SUMMARY OF THE INVENTION An object of the present invention invented in view of the above problems is to provide a method for automatically determining a ring manager using node information in a node information table in order to prevent an infinite loop of packets in a ring-type Ethernet network.

It is still another object of the present invention to provide a ring manager determination method for preventing a user error that may occur in a ring manager node setting step by a user and for reducing inefficiency of packet transmission caused by a blocking node. .

In the ring manager node determination method according to the present invention for achieving the above object, in a ring-type Ethernet network formed through the Ethernet ports, comprising a node having two or more Ethernet ports, the node of each node included in the network Creating a node information table including a type, a media access control address, and a port number and hop number connected between each node, and determining the presence or absence of a master node from the node information table created in the step; And determining the ring manager node based on the determination result. Here, a node requesting data is called a master node, and a node responding to the node is called a slave node.

The ring manager node determination method according to the present invention for achieving the above object, the node type of each node included in the ring-type Ethernet network, the media access control address, and the port number and hop (HOP) connected between each node Creating a node information table comprising a number; Determining the presence or absence of a master node from the node information table created in the above step, and if there is no master node, determining a node having a media access control address having the largest value from the created node information table as a ring manager node. It is composed.

The ring manager node determination method according to the present invention for achieving the above object, the node type of each node included in the ring-type Ethernet network, the media access control address, and the port number and hop (HOP) connected between each node Creating a node information table comprising a number; It is determined whether there is a master node from the node information table created in the above step, and if there is a master node, it is determined whether the total number of nodes included in the network is even. In the case where the total number of nodes is an even number, in each slave node of the created node information table, the number of hops with the master node is compared with each other through the Ethernet port of the slave node, and the master node is compared with the master node between the Ethernet ports. And determining a node having the same hop number as the ring manager node.

It is determined whether the total number of nodes included in the network is an even number, and when the total number of nodes is an odd number, in each of the slave nodes of the created node information table, the slave node is connected to the master node through each Ethernet port of the slave node. Comparing the number of hops and searching for a node having a difference of 1 in the number of hops with the master node between the Ethernet ports; The slave node having a large media access control address by comparing the media access control address of the node retrieved in the above step with the media access control address of the node most closely connected to the port having the large hop count of the slave node and the master node. Determining the ring manager node to be a ring manager node.

In the above, when two or more master nodes are adjacently connected, it is preferable to refer to the master node having the minimum media access control address among the master nodes.

In addition, the ring manager node determination method according to the present invention for achieving the above object further comprises the step of updating the node information table, and re-determining the ring manager node from the updated node information table.

In addition, the ring manager node determination method according to the present invention for achieving the above object, receiving a packet transmitted to one port by a node having two or more Ethernet ports to another port to determine whether the ring network It is configured to further include.

Hereinafter, a ring manager node determination method according to the present invention will be described in detail with reference to the accompanying drawings.

4A illustrates a ring manager node according to the present invention, and FIG. 4B illustrates a node that is not a ring manager according to the present invention. As shown in the figure, a gray node is a node determined as a ring manager node and shows an open state of packet relay logic, and a colorless node is a node not determined as a ring manager node and shows a state in which packet relay logic is closed. Indicates.

There is no hardware restriction on the opening and closing of the packet relay logic, and opening the packet relay logic means that the packet relay logic is not driven by hardware or software, and closed means that the packet relay logic is driven. it means.

FIG. 5 is a view illustrating a position determined as a ring manager node in a network in which one master node and an even number of nodes are even in accordance with the present invention. As shown in FIG. 5, a ring manager node is the opposite of a master node in a ring-type Ethernet network. Located in Therefore, slave node 3 located opposite to master node 1 is determined as the ring manager node.

FIG. 6 is a diagram illustrating a position where a ring manager node is determined in a network in which one master node and an total number of nodes is an odd number according to the present invention. As shown in FIG. Among them, a node with a large media access control address value. In FIG. 6, if the media access control address value of the slave node 3 is greater than the media access control address value of the slave node 2, the slave node 3 is determined as the ring manager node.

FIG. 7 is a diagram illustrating a location determined as a ring manager node in a network having two master nodes and an even number of nodes according to the present invention. As shown in FIG. Based on the master node, the ring manager node is located opposite to the master node. In FIG. 7, if the media access control address value of the master node 1 is smaller than the media access control address value of the master node 2, the slave node 2 located opposite to the master node 1 is determined as the ring manager node.

FIG. 8 is a diagram illustrating a location determined as a ring manager node in a network having two master nodes and an odd number of nodes according to the present invention. As shown in FIG. Based on the master node, the ring manager node is a node having a larger media access control address value among two nodes located opposite to the master node. In FIG. 8, assuming that the media access control address value of the master node 1 is smaller than the media access control address value of the master node 2, and the media access control address value of the slave node 2 is larger than the media access control address value of the slave node 1, Slave node 2 is determined to be the ring manager node.

FIG. 9 is a diagram illustrating a location where a ring manager node is determined in a network without a master node according to the present invention. As shown in FIG. 9, a node having a largest media access control address value is a ring manager node regardless of the total number of nodes. Is determined. In FIG. 9, it is assumed that the media access control address value of node 6 is the largest.

FIG. 10 is a diagram illustrating a process of updating a node information table and determining a ring manager node according to the present invention. As shown in FIG. 10, a node information table including a hop count is required to determine a ring manager node. .

All nodes in the network broadcast their information in a certain format. The node receiving the information of each broadcasted node increments the hop count by 1 and stores it in the node information table. The received node information is stored in the node information table and transmitted through the opposite port that received the packet. Repeating this process creates a node information table that contains the number of hops in each node. The node information table is regularly updated and maintained. Through the node information table created through this process, all nodes on the network can know which nodes are separated from their location by the number of hops in which direction. The node information table also includes media access control address values of all nodes in the network, and a node type representing a master or slave.

In addition, the node information table may use a routing table.

FIG. 11 is a flowchart illustrating a ring manager node determination process according to the present invention, as shown in FIG. 4A through FIG. 10, and particularly in the "ring confirmation" and "ring manager determination" process of FIG. 10. This is the process of determining whether it can be determined as a ring manager node. In other words, after checking whether the network is a ring or not, and then checking whether the network is a ring manager node. If it is determined that the current network is a ring network, it is determined whether it is determined as the ring manager node based on the information in the node information table it has.

To check whether there is a master node in the network, it is determined whether there is master node information in the node information table.

If there is no master node in the node information table, this is the case of FIG. 9. If the media access control address value of the master node is the largest using the node information registered in the node information table, it is determined as the ring manager node.

When there is a master node in the node information table, which corresponds to FIGS. 5 to 8, FIGS. 5 and 7 show an even number of nodes in the network, and FIGS. 6 and 8 show an odd number of nodes in the network. In order to simplify the decision process of the ring manager node regardless of the number of master nodes, the media node with small media access control address value is referred to. Of course, the media access control address value can be configured based on a large master node.

If there is a master node in the node information table and the total number of nodes in the network is odd, if the difference between the number of port zero direction hops and one port one direction hop from itself to the master node is one, then one of the two nodes opposite to the master node It becomes. Thus, an adjacent node in the direction of the highest number of hops from itself to the master node becomes the other node in the opposite direction of the master. In this case, the media access control address value of the immediately adjacent node is compared with the media access control address value of the immediate node. If the media access control address value is large, the ring manager node is determined.

In the present invention, since there are many well-known methods for the node information technique including the hop number and the method of implementing the same, there is no restriction on the node information table including the hop number. In addition, as shown in FIGS. 4A and 4B, when the hardware relay is not limited and the packet relay logic is open and closed, it means that the packet relay logic is not driven or driven in hardware or software. Therefore, the packet relay scheme does not limit whether hardware or software.

As described in detail above, the ring manager node determination method in the ring-type Ethernet network according to the present invention reduces the initial setup time of the network by eliminating the ring manager node configuration error by the user, and reduces the steps required for the user to reset. It works.

In addition, in the ring manager node determining method according to the present invention, in a ring-type Ethernet network including a master node and a slave node, an inefficient transmission path is determined by determining the ring manager node so that packets are not blocked between the master node and the slave node. Does not occur, and there is an effect of increasing communication efficiency.

Finally, the ring manager node determination method according to the present invention has the advantage of effectively preventing an infinite loop of packets through the determined ring manager node, especially in a ring-type Ethernet network broadcasting a packet.

Claims (9)

delete In the ring manager node determination method of a ring-type Ethernet network comprising nodes having two or more Ethernet ports, and formed through the Ethernet ports, Creating a node information table including a node type of each node included in the network, a media access control address, and a port number and hop number connected between the nodes; And Determining whether there is a master node from the node information table created in the above step, and if there is no master node, determining a node having a media access control address having the largest value as the ring manager node from the created node information table. How to determine which ring manager node to include. The method of claim 2, Determining the ring manager node, Determining a presence of a master node from the node information table, and if there is a master node, determining a ring manager node based on whether the total number of nodes included in the network is an even number. . The method of claim 3, wherein Determining the ring manager node, If the total number of nodes is even, In each of the slave nodes of the created node information table, the number of hops with the master node between the Ethernet ports is compared to the ring manager node by comparing the number of hops with the master node through each Ethernet port of the slave node. And determining the ring manager node. The method of claim 3, wherein Determining the ring manager node, If the total number of nodes is odd, In each of the slave nodes of the created node information table, a node having a hop number difference of 1 to a master node between the Ethernet ports is searched by comparing the hop number with the master node through each Ethernet port of the slave node. Making a step; Media access control address of the node that is most closely connected to the port of the direction of the hop number of the node and the master node of the node having a hop number difference of 1 between the master node between the discovered Ethernet ports is 1 Determining the slave node having a large value of the media access control address as a ring manager node by comparing the MAP. The method according to any one of claims 3 to 5, Determining the ring manager node, The method for determining a ring manager node according to claim 2, wherein the master node having the minimum media access control address among the master nodes when two or more master nodes are adjacently connected to each other. The method according to claim 2 or 3, Updating the node information table and re-determining a ring manager node from the updated node information table. The method according to claim 2 or 3, And receiving a packet transmitted to one port by a node having two or more Ethernet ports to another port to determine whether the network is a ring network. Multiple nodes having two or more Ethernet ports; Created based on the information transmitted by the nodes in a certain format, A node information table including a node type of each node, a media access control address, and a port number and hop number connected between each node; And And a ring manager node for destroying the packet transmitted from the node information table. The ring manager node, If there is no master node in the node information table, it is determined as the node having the largest media access control address from the created node information table, and if there is a master node, it is determined based on the total number of nodes included in the network. Ring-type Ethernet network having a ring manager node determination function, characterized in that.

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