JP2005184595A - Ring network system, and its communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IP packet transmission ring network system in which a routing table can be generated at low cost. <P>SOLUTION: Each of nodes 1 comprising a ring network notifies another node 1 of address information in which a MAC address of a terminal connected to a present node and a node address are paired, using a multi-address packet periodically or if a new terminal is connected to the present node. If a packet is received from the other node 1, each of the nodes 1 stores address information provided by the packet, learns and stores relay counts. Each of the nodes 1 comprises a MAC address table M for storing MAC addresses of terminals obtained from address information and an azimuth table D for storing the learnt minimum relay counts as routing tables. By referring to the routing tables, an IP packet transmission path between terminals connected to nodes is set to transmit a packet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a ring network system that transmits IP packets, and a communication control method thereof.

  A high-reliability network is demanded as the network speed increases by IP (Internet Protocol) communication. Highly reliable IP communication is highly compatible with a network having a redundant ring topology, and a node having a router function is connected to the ring network.

  The node decodes the address information of the source and destination for each packet, controls packet transmission, and controls IP communication between terminal devices connected to the node.

  FIG. 10 is a diagram illustrating an example of a ring network that performs IP communication using a ring topology.

  In FIG. 10, the ring network includes a first path 41 and a second path 42 connected in a ring shape, and a node 1x (# # connected to the first path 41 and the second path 42. 1 to #N). Each node 1x (# 1 to #N) includes a routing table R therein, and a host 2x or a personal computer 3x is connected as a terminal.

  If the personal computer 3x connected to the node 1x (# 1) tries to access the host 2x of the node 1x (# 3), a packet is transmitted from the personal computer 3x to the node 1x (# 1). Then, the node 1x (# 1) reads the MAC address of the host 2x as the destination terminal from the packet. Then, the routing table R is searched by the MAC address to find the node 1x (# 3) to which the host 2x is connected.

  Then, a communication path between the node 1x (# 3) and the node 1x (# 1) is set so that packets can be transmitted and received between the personal computer 3x and the host 2x.

  In order to realize this, the routing table R of each node 1x (# 1 to #N) includes MAC address information indicating which terminal is connected to which node as information necessary for communication path setting, and Path information between nodes transmitting packets is stored and held.

  There are two methods for generating the routing table R: “static routing” and “dynamic routing”.

  In “static routing”, information necessary for communication path setting is manually set by an operator's input operation. Therefore, processing for exchanging route information and traffic between nodes do not occur. However, if there is a change in a node or a terminal, it takes a lot of work time to correct the change.

  “Dynamic routing” is a method of setting the contents of the routing table R by a routing protocol that automatically finds and sets path information (see, for example, Non-Patent Document 1).

  Although this method saves labor for management, it is not only expensive because a routing protocol is installed in each node, but also has the problem of increasing the load on the CPU of the node.

As described above, conventionally, ring networks have a problem of costly generation of a routing table to be referred to for setting a route for transmitting a packet and a problem of increasing a load.
Internet Engineering Task Force (IETF) RFC 1058 (Request For Comments).

  The method of generating a routing table in a ring network has conventionally used “static routing”, which requires a great deal of labor to manage the routing table, or “dynamic routing” to reduce the labor of the management. However, there is a problem that the overhead burden on the CPU of the node is increased and the cost for generating the routing table is high.

  The present invention has been made to solve these problems, and an object thereof is to provide a ring network system using a routing table that can be generated at low cost, and a communication control method thereof.

  In order to achieve the above object, a ring network system of the present invention includes a first transmission path for transmitting a packet on a first path, and a packet on a second path opposite to the first path. A ring transmission line composed of a second transmission line for transmitting a plurality of nodes, a plurality of nodes connected to the first and second transmission lines, a node address of each node provided in the plurality of nodes, and A MAC address table in which MAC addresses of terminals connected to the respective nodes are stored correspondingly, and provided in the plurality of nodes, corresponding to node addresses of other nodes, from the other nodes A first relay count number obtained by updating relay count information included in a ring packet received using the first transmission path, and the ring packet received from the other node using the second transmission path. And a route table in which the first or second transmission path used when transmitting from the own node to the other node is stored. It is characterized by that.

  In the ring network system communication control method according to the present invention, a packet is transmitted on a first transmission path for transmitting a packet on a first path and on a second path opposite to the first path. A ring network system communication control method comprising a ring transmission line composed of a second transmission line and a plurality of nodes connected to the first and second transmission lines, wherein each of the plurality of nodes includes: A MAC address table in which a node address of each node and a MAC address of a terminal connected to each node are stored correspondingly, and corresponding to a node address of another node, A first relay count number obtained by updating relay count information included in a ring packet received using one transmission path, and the second relay count received from the other node using the second transmission path. A second relay count number in which the relay count information included in the packet is updated, and a route table in which the first or second transmission path used for transmission from the own node to the other node is stored. When transmitting a packet from the first terminal connected to the first node to the second terminal connected to the second node, the first terminal that has received the transmission packet from the first terminal The node of the second node interprets the MAC address of the second terminal as the transmission destination from the transmission packet, compares it with the MAC address table of its own node, and connects the second node to which the second terminal is connected. Obtain a node address, collate the node address of the second node with the route table of its own node, set the first or second transmission path to be transmitted to the second node, and set the destination A node address of the second node is set as a node address, and a ring packet encapsulated by adding to the transmission packet information in which the node address of the first node is set as a source node address is generated, The ring packet is transmitted to the set first or second transmission path.

  According to the present invention, each node of the ring network searches for and learns and stores the MAC address of the terminal connected to each node on the same ring network and the shortest path between the nodes without using a complicated routing protocol. It is possible to provide a ring network system capable of generating and operating a ring network routing table at low cost.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an embodiment of a ring network system according to the present invention.

  In FIG. 1, a ring network system (hereinafter referred to as a ring network) includes a first transmission path 2a and a second transmission path 2b connected in a ring shape, and the first and second transmission paths 2a, And a plurality of nodes 1 (#A to #C are shown in the figure) connected to 2b.

  The first transmission path 2a is a transmission path that transmits in the clockwise direction, and the second transmission path 2b is a transmission path that transmits in the counterclockwise direction. In the following description, the transmission direction of the first transmission path 2a is referred to as “route R”, and the transmission direction of the second transmission path 2b is referred to as “path L”.

  Each node 1 (#A to #C) includes a MAC address table M and a route table D, which are routing tables. Each node 1 (#A to #C) is connected to a host, personal computer, or the like as terminals P1 to P7. Here, “P1” to “P7” assigned to the terminals P1 to P7 connected to each node 1 (#A to #C) indicate the MAC addresses of the respective terminals.

  Each node 1 (#A to C) further includes a terminal interface 6 that transmits and receives packets to and from the terminal, and a network interface that transmits and receives packets between the first and second transmission paths 2a and 2b. 5, a CPU 7 connected to these interfaces via a bus, an internal memory 4 for storing a program executed by the CPU 7, a MAC address table M, and the like. Then, the CPU 7 performs monitoring control of the interface while searching for the routing table M stored in the internal memory 4 and executes packet transmission / reception control.

  The physical control of signals between the first and second transmission lines 2a, 2b and the network interface 5, the signals between the terminals P1 to P7 and the terminal interface 6, and the monitoring control operation between each interface and the CPU 7, Same as network. The present invention processes packet transmission / reception control with reference to the MAC address table M and the route table D provided as a routing table.

  Hereinafter, an operation in which each node 1 (#A to #C) stores or searches information necessary for packet transmission / reception control from the MAC address table M and the route table D will be described.

  FIG. 2 is a diagram illustrating a configuration of an IP packet transmitted on the ring network according to the embodiment.

  FIG. 2A shows a configuration of a packet transmitted and received between the node 1 (#A to #C) and the terminal, and is called an inter-terminal packet.

  In FIG. 2A, an inter-terminal packet includes an option field Op indicating packet type and other information auxiliary to transmission control, and a destination MAC address field DA indicating a destination terminal MAC address (here, each terminal's packet). MAC addresses are “P1” to “P7”.), A source MAC address field SA indicating a source terminal MAC address SA, a message field mf of a message body, and the like.

  FIG. 2B illustrates a case where nodes 1 (#A), (#B), when transmitting a terminal-to-terminal packet via the first transmission path 2a or the second transmission path 2b on the ring network, The structure of the packet transmitted / received between (#C) is shown. This packet is called a ring packet.

  The ring packet includes a destination node address field DN in which the node addresses of the destination nodes in the ring (here, the node addresses are “#A” to “#C”) are set in the inter-terminal packet, and the ring packet. Is a packet that encapsulates a terminal-to-terminal packet having a configuration in which a ring header composed of a source node address field SN in which a source node address of a source node is set and a relay count field TTL is added.

  Here, the relay count field TTL is a field indicating the number of times of relaying (count number) that is incremented by +1 every time the ring packet is relayed through the node 1 (#A to #C).

  FIG. 3 shows a MAC address table M that lists the MAC addresses of the terminals connected to each node 1 (#A to C).

  For example, when a message is transmitted from the terminal P1 of the node 1 (#A) to the terminal P5 of the node 1 (#C), the transmission source node 1 (#A) refers to the MAC address table M to The node address “#C” of the destination node 1 (#C) connected to the destination terminal P5 in the destination node field DN, and the node address “#A” of the source node (#A) in the source node field SN, respectively. Is set.

  FIG. 4 is a route table D indicating a route for transmitting a ring packet between the nodes 1 (#A to #C).

  The route table D stores a route for transmitting between nodes with a minimum number of relays, and stores different information for each node. For example, FIG. 4A shows the route table D of the node 1 (#A). That is, when the node 1 (#A) receives a packet from the node 1 (#B) on the “route R”, the relay is performed once for the “route R relay count” read from the received ring packet. When the packet is received by “Route L”, the fact that it has been received by two relays is stored in “Relay count number of route L”.

  The “number of relays on route L” in FIG. 4A is the number of relays until the node 1 (#C) arrives at the time of transmitting a packet to the node 1 (#C). The “transmission route” indicating the route to be transmitted from the node 1 (#A) to the node 1 (#B) has a larger relay count number, that is, the “relay route” having the smallest number of relays when transmitting. Road L "is set. Similarly, when the node 1 (#A) receives a packet from the node 1 (#C) on the “route R”, the fact that it has been received by two relays is stored in the “relay count number of the route R”. When a packet is received by “Route L”, the fact that it has been received by one relay is stored in “Relay count number of route L”. Then, the “route R” having the smaller number of relays is set in the “transmission route” indicating the route transmitted from the node 1 (#A) to the node 1 (#C). FIGS. 4B and 4C show route tables D of the node 1 (#B) and the node 1 (#C), respectively.

  Next, the schematic operation of the present embodiment will be described with reference to FIGS. FIG. 5 is a flowchart for explaining the operation of the ring network system of this embodiment. In FIG. 5, the central two routines represent the operation of node 1 (#A), the left routine represents the operation of node 1 (#C), and the right routine represents the operation of node 1 (#B).

  For example, the operation of the ring network when the terminal P1 connected to the node 1 (#A) transmits a packet to the terminal P6 connected to the node 1 (#C) will be described below.

  In the MAC address table M of each node 1 (#A to #C), the addresses “#A” to “#C” of the nodes and the MAC addresses “P1” to “P6” of the terminals shown in FIG. It is assumed that it has been set and stored.

  An inter-terminal packet in which the source MAC address “P1” is set in the source MAC address field SA of the header and the destination MAC address “P6” is set in the destination MAC address field DA together with the transmission data is transmitted from the terminal P1 to the node 1 ( #A) receives this (step s1). The node 1 (#A) reads the destination MAC address field DA of the inter-terminal packet (step s2) and searches the MAC address table M (step s3).

  Then, it is detected from the MAC address table M that the terminal P6 with the MAC address “P6” is connected to the node 1 (#C) (Yes in step s4).

  Next, in order to transmit the packet to the node 1 (#C), the node 1 (#A) transmits the packet using either the first transmission path 2a or the second transmission path 2b of the two ring networks. The route table D is checked to see if this is to be done. For example, referring to the route table D in FIG. 4A, in order to transmit a ring packet from the node 1 (#A) to the node 1 (#C), the “route R” (that is, the first transmission route) It can be seen that 2a) should be used (step s5).

  Then, a ring packet in which the node address “#C” is added to the destination node address field DN of the header part and the node address “#A” is added to the source node address field SN is generated, and the first transmission path 2a To the clockwise “route R” (step s6).

  When the node 1 (#C) receives the ring packet transmitted via the first transmission path 2a, the node address “#C” or a broadcast address “to be described later” is sent from the destination node address field DN of the header part. ff ”is read and determined as a packet addressed to the own node (Yes in step s7). Further, when the MAC address field DA “P6” of the destination terminal is read (step s7-1), it is determined that it is the MAC address “P6” of the terminal P6 of the own node (Yes in step s8), and the source node The address “#A” and the source terminal address “P1” are paired and stored in the MAC address table M, and the restored inter-terminal packet is transmitted to the terminal P6 (server) (step s9).

  On the other hand, in step s4, the MAC address (for example, MAC address “P7”) of the destination terminal that is not stored in the MAC address table M in the inter-terminal packet received by the node 1 (#A) from the terminal P1 is read. (No in step s4).

  In this case, the node 1 (#A) determines that there is a possibility that a terminal not registered in the MAC address table M is connected to the nodes 1 (#B) and (#C). The terminal-to-terminal packet transmission based on the search result is executed.

  Therefore, first, the node 1 (#A) transmits a ring packet encapsulating the inter-terminal packet to all the nodes 1 (#B) and (#C) in the broadcast mode. That is, a ring packet in which an address symbol for broadcast (here, “ff”) is set in the destination node address field DN, and a node address “#A” is set in the source node address field SN. Is generated. Then, the ring packet is transmitted via either the first transmission path 2a or the second transmission path 2b (step s10). For example, when a ring packet is transmitted using the second transmission path 2b, the node 1 (#B) receives this first.

  When the node 1 (#B) receives this ring packet, it reads the destination MAC address field DA (step s11). Based on the interpretation, it is recognized that the message is addressed to the terminal having the MAC address “P7”, but it is determined that the terminal P7 is not connected to the own node 1 (#B) (No in step s12). Therefore, the node 1 (#B) only stores the source node address “#A” and the source terminal address “P1” as a pair in the MAC address table M without taking in the inter-terminal packet again, and again The original ring packet with the broadcast address set is transmitted to the second transmission line 2b (step s13).

  When the node 1 (#C) receives the ring packet from the node 1 (#B) transmitted via the second transmission path 2b, the node 1 (#C) similarly reads the destination MAC address field DA (step s7). Then, it is determined that the terminal P7 having the read MAC address “P7” is connected to the own node (step 8 is YES). Therefore, the node 1 (#C) captures the inter-terminal packet, stores the source node address “#A” and the source terminal address “P1” as a pair in the MAC address table M, and sends it to the terminal P7 ( Step s9).

  In step s8, if the terminal P7 having the MAC address “P7” is not connected to the node 1 (#C), the node 1 (#C) transmits the source node address “#A” and the source terminal address “ By simply storing “P1” as a pair in the MAC address table M, it is assembled into a ring packet in which the broadcast address is set again without taking in the inter-terminal packet, and transmitted to the second transmission path 2b (step s8-1).

  In addition, when the terminal P7 having the MAC address “P7” is connected to the node 1 (#B) in Step s12 (Yes in Step s12), the node 1 (#B) transmits the source node address “#A ”And the source terminal address“ P1 ”are stored in the MAC address table M as a pair, and the inter-terminal packet is transmitted to the terminal P7.

  When the number of nodes is large, this operation is repeated in the same manner, and the ring packet is received in order until the ring packet transmitted with the broadcast address returns to the source node 1 (#A), and the MAC address table Repeat the storing operation to M and the relay operation to transmit to the next node.

  With the above operation, even if the terminal P7 having the destination MAC address “P7” is not stored in the MAC address table M of the node 1 (#A), the inter-terminal packet transmitted from the node 1 (#A) is Can be transmitted to the terminal P7 connected to the node 1 (#C).

  When step s7 is No, that is, when a packet that is not broadcast and is not addressed to the own node is received, the node 1 (#C) does not take in the inter-terminal packet and continues to the next node through the second transmission path 2b. (Step s7-2). Similarly, when step s11 is not No and a packet that is not addressed to its own node is received, node 1 (#B) transmits the same route as when the packet is received without receiving the inter-terminal packet. (Step s11-2).

  FIG. 6 is a flowchart illustrating a procedure for relaying a ring packet and an operation procedure for generating the MAC address table M by the ring network according to the embodiment. Hereinafter, an operation of generating the MAC address table M will be described with reference to FIGS. 1 to 4 and FIG.

  In FIG. 6, each node 1 (#A to #C) learns and stores the MAC address of the terminal connected to its own node in the MAC address table M.

  For example, when the node 1 (#C) receives a ring packet of a message transmitted from another node via the first transmission path 2a (step s61), the source node address field SN of the ring packet is read. Then, if the source node address of the ring packet is the own node address (Yes in step s62), it is discarded as it is because it is a ring packet transmitted by the own node (step s60).

  If the ring packet is not a local node address (No in step s62), the node 1 (#C) adds +1 to the relay count number in the relay count field TTL (step s63). If the added relay count number does not exceed the total number of nodes in the ring or a preset upper limit number (here, “3”) (No in step s64), the transmission source of the ring packet It is assumed that the node address (for example, node address (#A)) set in the node address field DN and the MAC address (for example, MAC address “P1”) set in the MAC address field of the transmission source terminal. ) As a set and stored in the MAC address table M of the node 1 (#C) (step s65). Note that even when the set of address information is already stored in the MAC address table M of the node 1 (#C), the stored contents are updated by overwriting the MAC address table M.

  In step s64, if the relay count exceeds the total number of nodes in the ring or a preset upper limit (step s64 is Yes), node 1 (#C) discards the received ring packet. (Step s60).

  Next, the node 1 (#C) reads the destination node address field DN and determines whether the broadcast address or its own node address is set (step s66). For example, if the own node address is set, it is determined whether the MAC address of the destination terminal is for a terminal connected to the own node (for example, the MAC address of the terminal P6) (step S67). If it is a terminal connected to the own node, the inter-terminal packet is transmitted to the terminal P6 having the MAC address “P6” (step s68).

  When node 1 (#C) finishes the above processing, it transmits the ring packet to the next ring node (here, node 1 (#B)) via first transmission path 2a (step 1). s69).

  In addition, when the destination node address of the ring packet received in step s66 is not an address addressed to the own node (step s66 is No), or when the packet is not a packet for the terminal connected to the own node in step s67 (step s67 is No). The node 1 (#C) transmits the ring packet to the next node via the first transmission path 2a (step s69).

  In this way, each node interprets the source node address set in the ring packet and the MAC address of the source terminal, so that, for example, the terminal P1 with the MAC address “P1” is connected to the node 1 (#A). Is read by the node 1 (#B, #C) and stored in the MAC address table M of each node.

  Each MAC address of the terminal connected to each node 1 (#A to #C) is set in each MAC address table M by initial setting of each node 1 (#A to #C) or by packet reception from the terminal. Is remembered. For example, even if the terminal is additionally connected after the initial setting and the MAC address (eg, MAC address “P7”) of the source terminal is not stored in each MAC address table M, the additionally connected terminal When an IP packet is transmitted from P7, node address / MAC address pair information is stored in each MAC address table M.

  However, if the terminal connected to the node (for example, the MAC address “P7”) is a reception-only terminal only by the above procedure, the MAC address “P7” is stored in each MAC address table M. I can't.

  Next, a method for storing the MAC address of the terminal additionally connected to the node in each MAC address table M will be described.

  FIG. 7 is a flowchart illustrating an operation procedure for additionally storing registration information of the terminal P7 having the MAC address “P7”, for example, in the MAC address table M of the ring network according to the embodiment.

  In FIG. 7, for example, when the node 1 (#C) reaches the time (for example, every predetermined period) for transmitting the route search information for notifying the MAC address (Yes in step s70), the node 1 (#C) enters the destination node address field DN A broadcast address “ff” is set, an identification code (for example, “1111”) indicating that it is route search information for notifying MAC address information is set in the option field Op, and transmitted to the source node address field SN The source node address (“#C”) is set, the address (“ff”) indicating the broadcast is set in the MAC address field DA of the destination terminal, and the added terminal is set in the MAC address field SA of the source terminal A ring packet in which the MAC address “P7” of P7 is set is generated. Then, the generated ring packet is transmitted to all the nodes connected to the ring network using either the first transmission path 2a or the second transmission path 2b (step s71).

  When nodes 1 (#A) and (#B) other than node 1 (#C) receive this ring packet, they recognize route search information by reading “1111” from the option field Op. Then, the operation of the procedure shown in FIG. 6 is executed.

  As a result, the nodes 1 (#A) and (#B) store the pair information of the MAC address “P7” and the node address “(#C)” in the MAC address table M in the own node.

  Note that this method of adding the MAC address of the terminal executes the procedure shown in FIG. 7 when the terminal is additionally connected to the node even if the period is not fixed, so that the latest MAC address information is stored in each MAC address table M. You may make it memorize.

  Thus, since each node 1 (#A to #C) transmits a packet notifying the MAC address of the terminal connected to its own node, even if a dedicated reception terminal is connected to the node The node MAC address / node address pair information can be notified to each node on the ring network.

  Now, in the embodiment, when the configuration of the ring network changes (addition etc.) or when a line failure occurs and the shortest route of the network relay path is changed, this information is automatically recognized in a short time. There are procedures.

  FIG. 8 is a flowchart illustrating an operation procedure in which the ring network according to the embodiment automatically recognizes the configuration change and generates the route table D. The route search information (routing) is transmitted from a specific node using FIG. The operation when transmitting a ring packet carrying information) to the ring network will be described.

  In FIG. 8, for example, when it becomes the transmission timing of the route search information (Yes in step s80), the node 1 (#C) sets “0” in the relay count field TTL and broadcasts it in the destination node address field DN. Is set, the source node address “#C” is set in the source node address field SN, and the code “1111” indicating route search information is set in the option field Op. Generated ring packet. In this ring packet, “00” is set in both the destination MAC address field DA and the source MAC address field SA. Then, the ring packet is simultaneously transmitted via the first transmission path 2a and the second transmission path 2b (step s81). Note that the transmission timing is a predetermined period of time, after a node is added, or before a node is reduced.

  FIG. 9 is a flowchart showing the operation of the node when a ring packet carrying route search information (routing information) is received.

  In FIG. 9, for example, the node 1 (#B) receives a ring packet carrying the route search information transmitted from the node 1 (#C) via the first transmission path 2a (“route R”). When it is received (step s91), “1111” is read from the option field Op to determine route search information (routing information).

  The node 1 (#B) interprets the source node address from the source node address field SN of the ring packet, and if it is a broadcast ring packet transmitted by its own node (Yes in step s92), the ring packet Is discarded (step s99). If the ring packet is transmitted from another node (No in step s92), the relay count number in the relay count field TTL is incremented by 1 (step s93).

  If the added relay count number is equal to or greater than the total number of nodes in the ring network or a preset upper limit number (here, “3”) (Yes in step s94), node 1 (# B) discards the ring packet (step s99).

  On the other hand, if the relay count number does not exceed the above condition in step s94, the node 1 (#B) corresponds to the “route R relay” corresponding to the transmission node address of the ring packet in the route table D in its own node. The relay count number after addition is set to “count number” (step s95).

  Similarly, when the node 1 (#B) receives the ring packet loaded with the route search information transmitted from the node 1 (#C) via the second transmission path 2b (“route L”). , Steps s91 to s94 are executed. Then, the node 1 (#B) sets the relay count number after addition to the “relay count number of the route L” corresponding to the transmission node address of the ring packet of the route table D in the own node (step s95). ). When a ring packet is received via the second transmission path 2b, since it is routed through the node 1 (#A), the “route L relay count” is set to “2” (step s95). ). That is, the route table D shown in FIG. 4B is created in the memory of the node 1 (#B).

  Thus, the node 1 (#B), when transmitting data with the node 1 (#C), sets the “route R relay count set by the ring packet loaded with the route search information received via the two transmission paths. Number (“1”) ”and“ relay count number of route L (“2”) ”are compared, and the larger second transmission path 2b is selected as a path to be transmitted to node 1 (#C). Then, “route L” is set in “transmission route” of the route table D (step s96).

  Until this operation is received at each node 1 (#A to #C) on the ring network by the node 1 (#C) as the transmission source, all the nodes 1 (#A ~ # C), the route table D is updated.

  In this way, for example, when it is found that the terminal P7 of the terminal MAC address “P7” is connected to the node 1 (#C) in the node 1 (#A), the shortest with reference to the route table D Information on the first transmission path 2a, which is a transmission transmission path, is obtained, and an inter-terminal packet can be transmitted to the node 1 (#C) via the first transmission path 2a.

  As described above, in the ring network of the present invention, while performing communication between terminals connected to each node on the ring network, the MAC address of the terminal in the routing table such as a MAC address table or a route table provided in each node, The shortest transmission path can be stored. This routing table generation and management method learns route information such as route and terminal MAC address without enlarging the protocol header, so the initial setting in the routing table may be minimized, and the ring A network can be provided at low cost.

The block diagram which shows the structure of the ring network system which concerns on the Example of this invention. The figure which shows the structure of the IP packet transmitted on the ring network system which concerns on the Example of this invention. The figure which shows the MAC address table of the ring network system which concerns on the Example of this invention. The figure which shows the route table of the ring network system which concerns on the Example of this invention. The flowchart which shows operation | movement of the ring network system based on the Example of this invention. The flowchart which shows the operation | movement which produces | generates the MAC address table of the ring network system which concerns on the Example of this invention. The flowchart which shows the operation | movement which adds a MAC address to the MAC address table of the ring network system which concerns on the Example of this invention. The flowchart which shows the production | generation operation | movement of the route table of the ring network system which concerns on the Example of this invention. The flowchart which shows the production | generation operation | movement of the route table of the ring network system which concerns on the Example of this invention. The block diagram which shows the structure of the conventional ring network system.

Explanation of symbols

1 Node 2a First transmission path ("Route R")
2b Second transmission line ("Route L")
4 Internal memory 5 Network interface 6 Terminal P1 to P7 Terminal MAC address DA Destination terminal MAC address field SA Source terminal MAC address field DN Destination node address field SN Source node address field TTL Relay count field Op Option field mf Message field

Claims (9)

A ring transmission path consisting of a first transmission path for transmitting packets in a first path and a second transmission path for transmitting packets in a second path opposite to the first path;
A plurality of nodes connected to the first and second transmission lines;
A MAC address table provided in the plurality of nodes, in which a node address of each node and a MAC address of a terminal connected to each node are stored correspondingly;
A first count provided in the plurality of nodes, wherein the relay count information included in the ring packet received from the other node using the first transmission path is updated corresponding to the node address of the other node. The relay count number, the second relay count number updated from the relay count information included in the ring packet received from the other node using the second transmission path, and the own node transmit to the other node A communication control method for a ring network system, comprising: a route table in which the first or second transmission path used at times is stored. A ring transmission path consisting of a first transmission path for transmitting packets in a first path and a second transmission path for transmitting packets in a second path opposite to the first path;
A ring network system communication control method comprising a plurality of nodes connected to the first and second transmission paths,
Each of the plurality of nodes is
A MAC address table in which a node address of each node and a MAC address of a terminal connected to each node are stored correspondingly;
Corresponding to the node address of the other node, the first relay count number updated from the other node and the relay count information included in the ring packet received from the other node using the first transmission path, from the other node The second relay count number updated in the relay count information included in the ring packet received using the second transmission path, and the first or second used when transmitting from the own node to the other node And a route table in which the transmission paths are stored,
When transmitting a packet from a first terminal connected to a first node to a second terminal connected to a second node,
The first node that receives the transmission packet from the first terminal is:
The MAC address of the second terminal of the transmission destination is read from the transmission packet, and the node address of the second node to which the second terminal is connected is obtained by comparing with the MAC address table of the own node. And
Check the node address of the second node and the route table of its own node to set the first or second transmission path to be transmitted to the second node,
A node packet of the second node is set as a destination node address, and a ring packet encapsulated by adding information in which the node address of the first node is set as a source node address to the transmission packet is generated. ,
A ring network system communication control method, wherein the ring packet is transmitted to the set first or second transmission path. Each of the nodes that have received the ring packet
From the ring packet, the node address of the first node of the transmission source and the MAC address of the first terminal of the transmission source are read,
3. The ring network system communication control method according to claim 2, wherein the node address of the first node and the MAC address of the first terminal are paired and stored in the MAC address table in the own node. . When the MAC address of the second terminal is not stored in the MAC address table of the first node,
The ring network system communication control method according to claim 2, wherein a broadcast ring packet in which a broadcast address is set as the destination node address is generated and transmitted to the first or second transmission path. Each node receiving the broadcast ring packet
Deciphering the MAC address of the second terminal from the broadcast ring packet;
The node address of the first node of the transmission source and the MAC address of the first terminal of the transmission source are paired and stored in the MAC address table of the own node,
5. The ring network system communication control method according to claim 4, wherein when it is determined that the second terminal is connected to its own node, the received packet is transmitted to the second terminal. The node to which the terminal is newly connected is
The broadcast address is set as the destination MAC address, the MAC address of the terminal connected to the own node is set as the source MAC address, and the identifier of the route search information for reporting that the terminal is newly connected is set. Generate a broadcast ring packet set in the header information,
3. The ring network system communication control method according to claim 2, wherein the broadcast ring packet is transmitted to the first or second transmission path. Each node receiving the broadcast ring packet
Read the source node address and source MAC address of the broadcast ring packet,
7. The ring network system communication control method according to claim 6, wherein the read source node address and the source MAC address are stored in the MAC address table of the own node. Each node has a predetermined time,
The broadcast address is set as the destination node address, the own node address is set as the source node address, the relay count number is set to 0, and the identifier of the route search information for checking the relay count number is set in the header information Generate a broadcast test ring packet,
3. The ring network system communication control method according to claim 2, wherein the broadcast ring packet is transmitted to the first and second transmission lines. Each of the nodes that received the test ring packet
Read the source node address of the test ring packet received from the first transmission path and the relay count number, update the relay count number and store it in the route table of its own node,
Read the source node address of the test ring packet received from the second transmission path and the relay count number, update the relay count number and store it in the route table of its own node,
Comparing the updated two relay counts, the larger transmission path is stored in the path table of the own node as a transmission path with the source node,
9. The communication control method for a ring network system according to claim 8, wherein the test ring packet with the relay count number updated is transmitted to the first and second transmission paths.

Images