JP4242262B2 - Communication system and terminal - Google Patents

Description

  The present invention relates to a communication system that generates network configuration information and network resource reservation information when a terminal constituting a network moves, and performs network management based on the information.

  As this type of relay device, there are a switching hub and a switching hub with a management function. These will be described below.

<Switching hub>
A general switching hub (including a bridge) has a filtering database (also called a MAC (physical) address learning table or a filtering table).

  When a packet arrives at a port with a switching hub, the switching hub stores the port that received the packet and the source MAC address in the filtering database in association with each other. It is memorized that it is connected ahead of.

  Here, “first” refers to the case where the terminal is connected directly to this port and the case where a further switching hub is connected to this port and the terminal is connected to the port of the further switching hub. Means to include.

  In addition, a plurality of transmission source MAC addresses may be stored for one port.

  By using the filtering database, the switching hub, when receiving a packet, looks at the destination MAC address of the packet and can identify which port to transfer to. The switching hub transfers packets by such a mechanism.

<Switching hub with management function>
A switching hub with a management function (including a bridge) receives management information (for example, a link status (link up / link) of a port in response to an inquiry from SNMP (Simple Network Management Protocol). Down), link speed (10 Mbps, 100 Mbps), filtering database for each port, etc.).

  Further, some switching hubs with management functions have a function called SNMP trap. The switching hub can notify the management server of any event related to itself (port link up / link down, occurrence of failure, etc.) by the SNMP trap.

  Originally, SNMP is a protocol for efficiently managing a network. In the conventional communication system, the management device acquires management information for each switching hub, for example, periodically using SNMP.

  A method for obtaining a LAN topology from a filtering database stored in a switching hub with a management function is described in Non-Patent Document 1.

  A conventional communication system is premised on a network having a personal computer as a terminal, and basically considers only a static topology. Therefore, it is impossible to respond immediately to the movement of the terminal.

  In the conventional communication system, the timing at which the value of the filtering database of the switching hub is updated is irrelevant to the movement of the terminal. The configuration information of the network it has does not match the actual configuration, which hinders network management.

  Here, it is self-evident that a situation in which not only a personal computer but also a network-compatible home appliance (net home appliance) is used as a terminal of this type will occur as technology advances.

  In the network environment represented by the Internet, communication is performed by dividing information into units called packets and transmitting the information.

  In general, transmission of packets is handled by best effort. This means that traffic for audio transmission and video transmission that requires real-time characteristics and traffic for file transfer that does not require real-time characteristics are handled in the same way. As a result, if the network is congested due to traffic such as a large amount of file transfer, the audio transmission and video transmission traffic will be affected, causing audio interruptions and video disturbances. End up.

  In order to perform audio transmission and video transmission that require real-time performance without hindrance, it is necessary to secure network resources on the communication path. As one method for reserving such network resources, a resource reservation protocol RSVP (Resource Reservation Protocol) is defined as an Internet standard in IETF (Internet Engineering Task Force). Are listed.

  In RSVP, before starting communication, network resources necessary for communication are secured in a relay device existing on a path with a communication partner. As a result, necessary network resources can be secured for each traffic, so that communication quality can be guaranteed.

  In addition, on the IEEE 802 LAN, SBM (Subnet Bandwidth Manager) is defined as a protocol for performing reception control and network resource management based on RSVP. This realizes bandwidth reservation in the data link layer of the second layer by a bandwidth management function called DSBM (Designated SBM). The contents are described in Non-Patent Document 3.

  Next, the operation of RSVP will be described. In RSVP, bandwidth reservation is performed by transmitting and receiving a control message between a relay device, a transmitting terminal, and a receiving terminal that support RSVP. The transmitting terminal transmits a “PATH” message describing the traffic characteristics of the data to be transmitted to the receiving terminal. The “PATH” message reaches the receiving terminal through the repeater along the communication path. The receiving terminal transmits a “RESV” message describing the network resources necessary for receiving it to the transmitting terminal. The network device on the route reserves its network resources according to the content of the “RESV” message. By doing so, resources for communication between the transmitting terminal and the receiving terminal are reserved. The reserved resource can be continuously held by periodically transmitting a “RESV” message.

  The resource reservation according to the prior art represented by the above-described protocols such as RSVP and SBM basically assumes a static network configuration, and reserves network resources along the communication path at the start of the service. A reservation message is periodically sent out so as to continue the process. Therefore, it does not sufficiently cope with a situation in which the terminal moves on the way and the network configuration changes. Examples of such problems of the prior art will be described below.

  That is, in the prior art, when the terminal moves and the communication path changes, a mismatch occurs between the communication path indicated in the reservation information and the actual communication path. While the state of inconsistency continues, the bandwidth of the communication of the terminal itself is not guaranteed, and there is a possibility that the network resource reservation of other terminals may be hindered.

  FIG. 22 is a diagram 1 illustrating an example of a path on a conventional network. Terminal 1 and terminal 2 are connected to repeater 6, terminal 3 is connected to repeater 7, and terminal 4 is connected to repeater 5. Further, the repeater 5 is connected to the repeater 6 and the repeater 7, and the whole constitutes a star-type network. Here, it is assumed that the transmission band between each repeater and between the repeater and the terminal is 10 Mbps.

  Now, the network resource for performing data transmission of the bandwidth 6 Mbps using the path P1 passing from the terminal 4 to the terminal 3 via the relay 5 and the relay 7, and the relay from the terminal 1 to the terminal 2 via the relay 6 It is assumed that a network resource for performing data transmission with a bandwidth of 6 Mbps is reserved using the path P2. Therefore, in this case, data transmission between the terminals is smoothly performed.

  Next, it is assumed that the terminal 2 moves from the state indicated by the solid line to the state indicated by the dotted line in the direction of the arrow M1 and changes the connection from the repeater 6 to the repeater 7. Immediately after this movement, no network resource reservation has been established for the new path P3. In this state, if the terminal 1 continues to transmit packets addressed to the terminal 2 without knowing that the terminal 2 has moved, congestion occurs between the repeater 5 and the repeater 7. That is, between the repeater 5 and the repeater 7, the bandwidth required for data transmission between the terminal 4 and the terminal 3 already used and the new path P3 between the terminal 1 and the terminal 2 are used. If it is going to do, the sum (12 Mbps) with a zone | band required for data transmission will exceed the transmission zone | band (10 Mbps) in the meantime, and it will interfere with each data transmission.

  In addition, the following problems occur.

  FIG. 23 is an exemplary diagram 2 of paths in the same network configuration as FIG. In FIG. 23, the network resources for the terminal 3 and the terminal 2 to transmit data in the band 6 Mbps using the path P4 reaching the terminal 2 from the terminal 3 via the repeater 7, the repeater 5, and the repeater 6. Have established a reservation. Assume that the terminal 2 moves from this state as indicated by an arrow M2 in FIG. 23, changes its connection from the repeater 6 to the repeater 7, and changes to a new path P5. Immediately after the movement, the network resource of the path P4 used by the terminal 2 until now has not been released yet. At this time, even if the terminal 4 tries to reserve the network resource of the path P6 in order to start data transmission of 6 Mbps with the terminal 1 via the repeater 5 and the repeater 6, Since the network resource reservation with the repeater 6 has not yet been released, it cannot be reserved even though it can actually be reserved.

  The problems described above occur because resource reservation according to the prior art represented by protocols such as RSVP and SBM cannot instantly cope with terminal movement.

  The behavior of general users who use Internet home appliances is unpredictable, and it is conceivable that the terminal moves more frequently than when only a personal computer is used as the terminal.

  For example, it is conceivable that the user pulls out a cable connected to a television device (net home appliance) that is receiving video and inserts it into another port. In that case, the communication path through which the video data flows changes, which may affect the service of another home appliance.

  Furthermore, when the network is composed of a plurality of fixed repeaters and a plurality of terminals (computers, portable image processing devices, etc.) wirelessly connected to these repeaters, the connection destination of the terminals is It is rather a premise to change from moment to moment, and it is expected that the above-described conventional technology will not be able to cope with it.

In recent years, in wireless LANs and mobile environments that have been remarkably widespread, it is obvious that a change in communication path accompanying the movement of a terminal frequently occurs, and a solution for that is necessary.
RFC2108 “Definitions of Managed Objects for IEEE 802.3 Repeater Devices using SMIv2”, p. 75 Section 4. Topology Mapping. RFC2205 “Resource Reservation Protocol (RSVP) —Version 1 Functional Specification”. RFC2814 "Subband Bandwidth Manager (SBM): A Protocol for RSVP-based Admission Control over IEEE 802-style networks".

  In view of this, the present invention provides a network that can reserve network resources. When a terminal moves and the network configuration and the network resource reservation status are changed, these changes are immediately reflected in the configuration information and reservation information of the management device. It is an object of the present invention to provide a communication system that can reserve necessary network resources.

  The communication system according to claim 1 is a network configuration information including a plurality of relay devices, a terminal connected to one of the ports of the relay device, and the relay device and the terminal. The relay device includes a plurality of ports and a MAC address table that stores information on the source MAC address for each of these ports. When the packet reception unit that receives the packet, the packet transmission unit that transmits the packet, the link state detection unit that detects the link up to the relay device, and the link state detection unit detect the link up, the packet transmission unit is used. And a change notification unit for notifying the management device that the network configuration has been changed.

  With this configuration, the management apparatus can quickly detect the movement of the terminal and the movement destination thereof, and can quickly reflect the network configuration change in the network configuration information.

  In the communication system according to claim 2, the notification is performed by transmitting a link change notification dedicated packet.

  With this configuration, link change notifications from various terminals can be uniformly processed by a simple method.

  In the communication system according to the third aspect, the notification is performed by transmitting a substitute packet other than the link change notification dedicated packet.

  With this configuration, it is not necessary to transmit a dedicated packet for link change notification, the burden of transmission / reception can be reduced, and an increase in the amount of traffic on the communication path can be suppressed.

  In the communication system according to claim 4, the notification by the substitute packet transmits any one of an ICMP message, service information that can be provided by the terminal, and telephone number information of the terminal.

  With this configuration, it is promised in advance that link change notification information is exchanged between each terminal and the management apparatus, and the terminal informs that the link has been changed by transmitting a substitute packet including the substitute information. I can do it. For example, when detecting a link change, the terminal can send an ICMP (Internet Control Message Protocol) message as alternative information to notify that the link has been changed. Alternatively, when the terminal is a server or the like, it is possible to notify that the link has been changed by transmitting service information that can be provided by the server as alternative information. Furthermore, when the terminal is an IP telephone, it is possible to notify that the link has been changed by transmitting telephone number information of the IP telephone as alternative information.

  In the communication system according to claim 5, the notification is performed by multicast and / or broadcast.

  With this configuration, it is possible to rewrite the MAC address tables of the relay devices configuring the network all at once.

  The communication system according to claim 6 includes an information acquisition unit that receives information from the relay device about the MAC address of each port when the management device receives a notification from the terminal, and the configuration information generation unit includes: The network configuration information is updated based on the acquired information.

  With this configuration, the time until the management apparatus detects a network configuration change is shortened.

  In the communication system according to claim 7, the information acquisition unit acquires information of the MAC address using SNMP.

  With this configuration, the MAC address information can be acquired without significant change from the conventional communication system.

  In the communication system according to the eighth aspect, the information acquisition unit acquires the MAC address information only from the relay device existing on the path from the port related to the notified terminal to the management device.

  With this configuration, the management apparatus can grasp a change in the configuration of the network with a minimum amount of information collection, and this information collection prevents the bandwidth used by other communications from being compressed.

  The communication system according to claim 11 includes a plurality of relay devices and a terminal connected to any one port of the relay devices among the relay devices, and the terminal includes a packet receiving unit that receives a packet; A packet transmission unit that transmits a packet, a link state detection unit that detects a link-up to the relay device, a resource reservation table that stores network resource reservation information between the own terminal and another terminal, and a link state detection unit, When link up is detected, the packet transmission unit has a change notification unit that notifies network resource reservation information stored in the resource reservation table to other terminals of the network.

  With this configuration, it is possible to quickly detect the movement of a terminal, quickly release network resources that are no longer necessary as the terminal moves, and quickly reserve new network resources that are needed. Use and high-quality communication can be realized.

  In the communication system according to claim 12, notification of network resource reservation information is performed by multicast and / or broadcast.

  With this configuration, network resource reservation information accompanying terminal movement can be notified all at once, and efficient network operation becomes possible.

  In the communication system according to the thirteenth aspect, the notification of the network resource reservation information is performed only to the communication partner terminal stored in the resource reservation table.

  With this configuration, the network resource reservation information can be updated with a minimum notification. Therefore, waste can be eliminated.

  In the communication system according to the fourteenth aspect, securing of network resources based on the network resource reservation information is performed by RSVP.

  With this configuration, necessary network resources can be secured without significant changes from the conventional communication system.

  The communication system according to claim 15 is a network resource of a network constituted by a plurality of relay devices, a terminal connected to one of the ports of the relay device, and the relay device and the terminal. A management apparatus having a network resource management table for storing reservation information and a network resource management unit for managing network resources, wherein the terminal receives a packet, and receives a packet and transmits a packet A link status detection unit that detects link-up to the relay device, a resource reservation table that stores network resource reservation information between the local terminal and another terminal, and a link status detection unit that detects link-up, Using the transmitter, the network stored in the resource reservation table The Kurisosu reservation information, and a change notifying unit that notifies the management device.

  With this configuration, the management apparatus can quickly grasp the network resources that are no longer needed and the network resources that are newly needed as the terminal moves, and can efficiently operate the network.

  In the communication system according to claim 16, in the management device, the network resource management unit includes reservation availability information that determines whether or not the network resource reservation requested by the terminal is available with respect to the network resource reservation information received from the terminal. The network resource reservation information in the network resource management table is updated based on the reservation availability information, and the reservation availability information is notified to the terminal and the terminal of the communication partner of the terminal.

  With this configuration, the management apparatus can determine whether or not to reserve a network resource for the network resource reservation information from the terminal, and notify the terminal and the terminal of the communication partner of the terminal, so that the network resource can be unified. Management becomes possible.

  The communication system according to claim 19 manages a network including a plurality of relay devices, a terminal connected to one of the ports of the relay device, and the relay device and the terminal. The relay device includes a plurality of ports and a MAC address table that stores a source MAC address for each of the ports, and the terminal includes a packet receiving unit that receives the packet; A packet transmission unit for transmitting packets, a link state detection unit for detecting link-up to a relay device, a resource reservation table for storing network resource reservation information between the own terminal and other terminals, and a network configuration are changed. And a change notification unit for notifying the management device of the network resource reservation information, and the management device receives the packet. A packet receiving unit, a packet transmitting unit for transmitting a packet, an information acquiring unit for acquiring MAC address information about each port from the relay device, a configuration information generating unit for generating network configuration information, and a network of the network A network resource management table for storing resource reservation information and a network resource management unit for managing network resources of the network. When the link state detection unit detects a link up in the terminal, the network configuration is changed. Information is received and the network resource reservation information stored in the resource reservation table is transmitted to the management unit using the packet transmission unit, and when the notification is received from the terminal in the management device, information is acquired. The MAC address associated with each port from the relay device. The configuration information generation unit updates the network configuration information based on the information acquired by the information acquisition unit, and the network resource management unit receives the network resource reservation information received from the terminal. Create reservation availability information that determines whether or not the network resource requested by the terminal can be reserved, update the network resource reservation information in the network resource management table based on the reservation availability information, and send the reservation availability information to the communication between the terminal and the terminal. Notify the other terminal.

  With this configuration, the management apparatus can quickly detect the movement of the terminal and the movement destination thereof, and can quickly reflect the network configuration change in the network configuration information. Further, the time until the management apparatus detects a network configuration change is shortened. Furthermore, the management apparatus can quickly grasp the network resources that are no longer necessary and the network resources that are newly required as the terminal moves, and can efficiently operate the network.

  In the communication system according to claim 20, the notification is performed by transmitting a link change notification dedicated packet.

  With this configuration, link change notifications from various terminals can be uniformly processed by a simple method.

  In the communication system according to claim 21, the notification is performed by transmitting an alternative packet other than the link change notification dedicated packet.

  With this configuration, it is not necessary to transmit a dedicated packet for link change notification, the burden of transmission / reception can be reduced, and an increase in the amount of traffic on the communication path can be suppressed.

  In the communication system according to the twenty-second aspect, the notification by the substitute packet transmits any one of an ICMP message, service information that can be provided by the terminal, telephone number information of the terminal, and network resource reservation information.

  With this configuration, it is promised in advance that link change notification information is exchanged between each terminal and the management apparatus, and the terminal informs that the link has been changed by transmitting a substitute packet including the substitute information. I can do it. For example, by sending an ICMP message from the terminal, service information that can be provided by the server when the terminal is a server, telephone number information when the terminal is an IP phone, or network resource reservation information as alternative information, You can be informed that the link has changed.

  In the communication system according to a twenty-sixth aspect, the relay device is a base station configuring a wireless LAN, and the link state detection unit of the terminal detects a change in connection with the base station as a link up.

  This configuration enables efficient operation of a network configured using a wireless LAN.

  According to the present invention, even when a terminal moves, the network can be managed so that the configuration information of the network held by the management apparatus matches the actual configuration and the network resources can be used effectively.

(First embodiment)
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a terminal according to the first embodiment of the present invention, and FIG. 2 is a block diagram of the management apparatus.

  As shown in FIG. 1, the terminal 10 of this embodiment has the following elements. The packet transmission unit 11 transmits a packet to the outside. The packet receiving unit 12 receives a packet from the outside.

  Here, as shown in FIG. 6C, the packet is provided with fields for storing the destination MAC address and the source MAC address.

  These MAC addresses are uniquely assigned to each device (management device, relay device, terminal, etc.) constituting the network, for example, “00: 20: 44: 00: 01: 00”. Is something. In the following, including the figure, the MAC address of the component having the symbol * is displayed as “m *”.

  In FIG. 1, the link state detection unit 13 detects whether the terminal 10 is in a link-up (connected) / link-down (disconnected) state at a port of the relay device. Here, when the terminal 10 is connected to the relay device by wire, the link state detection unit 13 connects / disconnects a cable (for example, an Ethernet (registered trademark) cable) to the port of the relay device. It is detected whether it was done.

  On the other hand, when the terminal 10 is connected to the relay device wirelessly, the link state detection unit 13 is referred to as a “port” including the wireless side of the relay device (in the present specification, including this “wireless side”). That is, the meaning of “port” in this specification is broader than that of a general one).

  For example, the link state detection unit 13 assumes that the terminal 10 is connected to the relay device when the terminal 10 detects the relay device that is a base station or after a short time, and the relay device that is a base station. It is preferable that the terminal 10 is disconnected from the relay device when handed over from the terminal.

  When the link state detection unit 13 detects a link up, the change notification unit 14 transmits a packet to the management apparatus 20 using the packet transmission unit 11 to notify that the network configuration has been changed. This notification is performed by multicast or broadcast.

  As shown in FIG. 2, the management apparatus 20 has the following elements. The packet transmission unit 21 transmits a packet to the outside. The packet receiving unit 22 receives a packet from the outside.

  When receiving the notification from the terminal 10, the information acquisition unit 23 acquires the MAC address information regarding each port of the relay device. All the relay apparatuses of this embodiment are switching hubs or bridges with management functions, and the information acquisition unit 23 acquires information on the MAC address using SNMP. The information acquisition unit 23 acquires the MAC address information only from the relay device existing on the route from the port related to the terminal that has made the notification to the management device 20.

  The information acquisition unit 23 does not acquire the information of the MAC address table of all the relay devices, but the route from the relay device to which the management device 20 is connected to the relay device to which the terminal that issued the change notification is connected And only the information of the MAC address table of the relay device on the route is acquired. That is, when the management device 20 receives a change notification from a terminal, first, the information acquisition unit 23 acquires information of the MAC address table of the relay device to which the management device 20 is connected. The process of confirming which relay device is connected and acquiring the information of the MAC address table of the next connected relay device tube is repeated until the terminal is reached. As a result, the configuration information can be updated with only the minimum MAC address table information.

  The configuration information generation unit 24 generates configuration information of relay devices and terminals that configure the network based on the latest MAC address information acquired by the information acquisition unit 23.

  As shown in FIG. 3A, the relay device 50 has a MAC address table 59, and includes a second port 52 and a plurality of ports (six in the illustrated example). The numbers in the circles indicating ports are port numbers.

  As shown in FIG. 3B, the MAC address table 59 stores each port number and a transmission source address related thereto. There may be no source MAC address corresponding to each port number, there may be only one, or there may be two or more.

  The configuration information generated by the configuration information generation unit 24 is illustrated in FIG. 4, for example. In the example shown in FIG. 4, the management device 20 is connected to the first port 51 of the relay device 50, the third port 53 of the relay device 50 is connected to the second port 62 of the relay device 60, and Number port 66 is connected to the terminal 100. Further, the sixth port 56 of the relay device 50 is connected to the fifth port 75 of the relay device 70, the third port 73 of the relay device 70 is connected to the terminal 80, and the sixth port 76 of the relay device 70 is connected to the terminal 90. It is connected to the.

  Of course, the configuration information shown is merely an example, and various changes may be made as long as the connection relation of the network can be uniquely understood.

  Next, a process of configuring the configuration information will be described with reference to FIGS. 3 and 5 to 8. As shown in FIG. 3A, when no terminal is connected to the relay device 50, as shown in FIG. 3B, in the MAC address table 59, the source MAC address of each port is , Nothing is stored.

  Next, it is assumed that the terminal 10 is connected to the second port 52 as shown in FIG. At this time, the link state detection unit 13 of the terminal 10 detects link up.

  However, until the terminal 10 transmits the packet to the relay device 50, as shown in FIG. 5B, the contents of the MAC address table 59 are the same as the state of FIG.

  Next, as indicated by an arrow N1 in FIG. 6A, when the terminal 10 transmits a packet and this packet arrives at the relay device 50, the contents of the MAC address table 59 are as shown in FIG. 6B. Will be changed. That is, the MAC address “m10” of the terminal 10 is set as the source MAC address for the second port 52.

  As shown in FIG. 7A, it is assumed that the third port 63 of the relay device 60 is connected to the first port 51 of the relay device 50. At this time, as shown in FIG. 7B, no MAC address is stored in the MAC address table 69.

  Next, as indicated by an arrow N1 in FIG. 8A, the terminal 10 transmits a packet, and when this packet is transmitted as indicated by an arrow N2 and arrives at the relay device 60, the MAC address table 59 The content is set by adding the MAC address “m60” of the repeater 60 to which the first port 51 is connected as shown in FIG. At the same time, the contents of the MAC address table 69 are changed as shown in FIG. That is, the MAC address “m10” of the terminal 10 and the MAC address “m50” of the repeater 50 are set as the transmission source address for the third port 63.

  When the above processing is repeated, a network as shown in FIG. 9 is configured. At this time, the IP address and MAC address of each component are as shown in FIG. 10, for example.

  At this time, the contents of the MAC address table 59 are as shown in FIG. 11A, the contents of the MAC address table 69 are as shown in FIG. 11B, and the contents of the MAC address table 79 are as shown in FIG. As shown in c).

  In FIG. 11A, the third port 53 will be described as an example. The third port 53 stores the MAC address of the relay device 60 and the MAC address of the terminal 100. Here, the third port 53 is directly connected to the second port 62 of the relay device 60, and is connected to the terminal 100 via the relay device 60 at the destination (6th port 66).

  In the present embodiment, it is not distinguished whether the third port 53 is directly connected or connected via some relay device.

  In other words, the presence of a MAC address at the corresponding port number indicates that there is a device storing the MAC address at the end of this port (any position in this direction). Thereby, the management apparatus 20 can know the route to each relay apparatus or each terminal.

  Next, the process from when a new connection is made until the configuration information is updated will be described with reference to FIG.

  In step 1, the terminal 10 is connected to a new port. Next, in step 2, the link state detection unit 13 of the terminal 10 detects link up.

  In step 3, the change notification unit 14 of the terminal 10 transmits a change notification packet to the management apparatus 20. This transmission is performed by multicast or broadcast. The MAC address table of the relay device on the path through which this packet is transmitted is changed.

  In step 4, the management apparatus 20 sends an information request to the relay apparatus related to this route. In step 5, the latest information of the MAC address table is transmitted in the direction opposite to the direction of the information request, and the information acquisition unit 23 acquires it.

  In step 6, the configuration information generation unit 24 updates the configuration information based on the latest information acquired by the information acquisition unit 23.

  Next, the operation when the terminal 100 moves will be described with reference to FIG. First, it is assumed that the terminal 100 is connected to the sixth port 66 of the relay device 60 as indicated by a broken line in FIG.

  At this time, the contents of the MAC address table 59 are as shown in FIG. 11A, the contents of the MAC address table 69 are as shown in FIG. 11B, and the contents of the MAC address table 79 are as shown in FIG. .

  As shown in FIG. 13, it is assumed that the terminal 100 is linked down from the sixth port 66, moved in the arrow N10 direction, and linked up to the first port 71 from this state.

  The contents of the MAC address tables 59, 69, and 79 remain as shown in FIG.

  Next, the terminal 100 transmits a change notification packet by multicast or broadcast. By this transmission, the contents of the MAC address tables 59, 69, and 79 are changed as shown in FIG.

  Here, as apparent from a comparison between FIG. 11 and FIG. 14, “m100” is deleted from the third port 53 of the MAC address table 59 and “m100” is added to the sixth port 66 of the MAC address table 69. “M100” is added to the first port 71 of the MAC address table 79 and “m100” is deleted from the fifth port 75.

  Next, the information acquisition unit 23 requests the relay devices 50, 60, and 70 to transmit the latest information, as indicated by arrows N14, N15, and N16. On the other hand, the relay devices 50, 60, 70 transmit the contents of the MAC address tables 59, 69, 79 to the information acquisition unit 23 in the direction opposite to these arrows.

  When the information acquisition unit 23 receives this transmission, the configuration information generation unit 24 updates the configuration information based on the transmission.

  The conventional communication system suffices to be able to detect the failure of the network mainly, so that it is not necessary to immediately know that the terminal has moved, and there is no means for detecting the movement of the terminal.

  Here, as shown in FIG. 13, in the state immediately after the terminal 100 is linked up to the first port 71 (before the terminal 100 transmits the change notification packet), the MAC address table of the relay apparatus is updated. Therefore, the management device 20 cannot know whether the terminal 100 has moved. At this time, even if the information acquisition unit 23 requests the MAC address tables 59, 69, and 79 to transmit information, the management device 20 erroneously recognizes that the terminal 100 is connected to the sixth port 66. End up.

  Incidentally, if the SNMP trap is used, the management apparatus 20 can detect the link down of the sixth port 66 and the link up of the first port 71. However, there is also a problem in this case, and the management apparatus 20 has linked the terminal 100 to the first port 71 by moving, and that another terminal different from the terminal 100 has linked to the first port 71. And cannot be distinguished.

  In order to avoid this, it is also conceivable that the management apparatus 20 that has received the SNMP trap notification transmits a broadcast packet that requests a response to all terminals, not the relay apparatus. However, in this case, since a large number of terminals can generally exist, a huge amount of broadcast packets are transmitted, resulting in a pressure on the band used by other communications.

  Therefore, in this embodiment, when the terminal 100 detects a link up, the terminal 100 itself (usually, only one) that is linked up issues a change notification to the management apparatus 20. As a result, updating of the MAC address table of the relay device and detection of terminal movement (change of configuration information) by the management device 20 can be performed simultaneously.

  By performing this notification by multicast (or broadcast), it is possible to update the MAC address tables of all the relay apparatuses constituting the network.

  That is, since the location of the terminal (direction in which it is connected) can be taught to all the relay apparatuses, when the terminal moves (new connection), the connection location can be quickly identified. This is effective for a communication system that needs to accurately manage topology information.

  In the above description, it is assumed that the terminal 100 transmits a link detection notification incorporated in a link change notification dedicated packet when link up is detected.

  However, this link detection notification need not use a link change notification dedicated packet. That is, each terminal and the management device promise in advance alternative information for link change notification, and the terminal can notify that the link has been changed by transmitting an alternative packet including the alternative information. I can do it. For example, instead of sending a dedicated packet for link change notification, the terminal may execute a so-called ping (TCP / IP network diagnostic program called Packet Internet Grouper) and send a substitute packet including an ICMP message as substitute information. . Alternatively, when the terminal is a server or the like, it is possible to notify that the link has been changed by transmitting a substitute packet including service information that can be provided by the server as substitute information. Further, when the terminal is an IP phone, it is possible to notify that the link has been changed by transmitting a substitute packet including the phone number information of the IP phone as substitute information.

  Alternatively, another alternative packet in which a link change notification is incorporated in a part of the alternative information may be transmitted.

  Such an alternative packet is transmitted by broadcast or multicast.

  In this way, instead of transmitting the link change notification dedicated packet, the terminal and the management apparatus promise in advance alternative information of the link change notification and transmit the alternative packet including the alternative information. In this case, the transmission path is not occupied to transmit the dedicated packet.

(Second Embodiment)
FIG. 15 is a block diagram of a terminal according to the second embodiment of the present invention, and FIG. 16 is a block diagram of the management apparatus. In FIG. 15 and FIG. 16, the same components as in FIG. 1 and FIG.

  As illustrated in FIG. 15, the terminal 10 according to the present exemplary embodiment includes a packet transmission unit 11, a packet reception unit 12, a link state detection unit 13, a change notification unit 14, and a resource reservation table 15.

  When the link state detection unit 13 detects a link up, the change notification unit 14 uses the packet transmission unit 11 to transmit a packet to the management device 20 to notify that the network configuration has been changed. This process is the same as in the first embodiment of the present invention. Further, the change notification unit 14 notifies the management device 20 of the network resource reservation information stored in the resource reservation table 15 using the packet transmission unit 11. This notification is performed by multicast or broadcast. A specific example of the resource reservation table 15 will be described later.

  As shown in FIG. 16, the management apparatus 20 of this embodiment includes a packet transmission unit 21, a packet reception unit 22, an information acquisition unit 23, a configuration information generation unit 24, a network resource management table 25, and a network resource management unit 26. Have.

  When the information acquisition unit 23 receives a notification from the terminal 10 that the network configuration has been changed, the information acquisition unit 23 acquires MAC address information regarding each port of the relay device. All the relay apparatuses of this embodiment are switching hubs or bridges with management functions, and the information acquisition unit 23 acquires information on the MAC address using SNMP. The information acquisition unit 23 acquires the MAC address information only from the relay device existing on the route from the port related to the terminal that has made the notification to the management device 20. The process of acquiring the MAC address information is the same as that in the first embodiment of the present invention, and a description thereof will be omitted.

  The configuration information generation unit 24 generates configuration information of the relay devices and terminals that configure the network based on the latest MAC address information acquired by the information acquisition unit 23. The configuration information generation process and configuration results are the same as those in the first embodiment of the present invention, and a description thereof will be omitted.

  Upon receiving the notification of the network resource reservation information from the terminal 10, the network resource management unit 26 examines the content, determines whether the requested network resource reservation is possible, and creates reservation availability information. The network resource reservation information in the network resource management table 25 is updated based on the created reservation availability information. Furthermore, the network resource management unit 26 notifies the terminal 10 and the communication partner terminal of the created reservation availability information.

  Next, a network resource reservation process will be described with reference to FIGS. In the following description, it is assumed that the bandwidth between each terminal and a repeater and between each repeater is 10 Mbps.

  FIG. 17 is an exemplary diagram 1 of a path on the network according to the present embodiment. In FIG. 17, the terminal 100 connected to the third port 63 of the repeater 60 transmits a packet to the terminal 80 also connected to the sixth port 66 in the direction indicated by the arrow N18. Suppose that the bandwidth is reserved. Further, the terminal 110 connected to the second port 52 of the repeater 50 transmits a packet to the terminal 90 connected to the sixth port 76 of the repeater 70 in the direction of the arrow N19. Suppose that the bandwidth is reserved.

  At this time, network resource reservation information as shown in FIG. 19A is stored in the resource reservation table 15 of the terminal 100. The resource reservation table 15 includes a “reservation ID” field indicating a reservation number, a “transmission source” field indicating a packet transmission source, a “destination” field indicating a packet destination, and a “communication path” field indicating a packet communication path. And a “reserved bandwidth” field indicating a bandwidth used for packet transmission. In this case, “reservation ID” is “2”, MAC addresses “m100” and “m80” representing the respective terminals are stored in “transmission source” and “destination”, and “communication path” is stored in “communication path”. The MAC address “m100” of the transmission source, the MAC address “m60” of the repeater on the communication path, and the MAC address “m80” of the “destination” are stored side by side in the order of the communication path. The “reserved bandwidth” stores the bandwidth “6 Mbps”.

  In the resource reservation table 15 of the terminal 110 which is another transmission source, the network resource reservation information shown in FIG. 19B is stored as “reservation ID” = “1”.

  Reservation reservation of these network resources is performed by the change notification unit 14 of each terminal (in the above example, the terminal 80 and the terminal 90) illustrated in FIG. 15 using RSVP.

  The management device 20 receives network resource reservation notifications from the respective transmission sources and manages the network resources of the entire network. In this case, in the network resource management table 25 of the management apparatus 20, as shown in FIG. 19C, similarly, a “reservation ID” field, a “transmission source” field, a “destination” field, a “communication path” field, In addition, a “reserved bandwidth” field is prepared. The “reservation ID” stores a reservation number, the “transmission source” and the “destination” store MAC addresses representing the respective terminals, and the “communication path” stores the MAC address of the transmission source on the communication path. The MAC address of the repeater and the MAC address of the “destination” are stored in the order of the communication path. The “reserved bandwidth” stores a bandwidth used for packet communication.

  The network resource management unit 26 manages the network resources so that no congestion occurs in any communication path by looking at all the reservation statuses in FIG. In the state of FIG. 17, communication congestion does not occur in any section.

  Next, FIG. 18 is an exemplary diagram 2 of a path on the network of this embodiment. As shown in this figure, it is assumed that the terminal 80 moves in the direction indicated by the arrow N20 and the connection is changed from the repeater 60 to the repeater 70. That is, the route from the terminal 100 to the terminal 80 is changed from the arrow N18 in FIG. 17 to the arrow N21 in FIG. Then, the link state detection unit 13 of the terminal 80 detects a change in the link state, the change notification unit 14 notifies that the network configuration has been changed, and the configuration information generation unit 24 of the management device 20 Generate new network configuration information.

  In addition, the change notification unit 14 of the terminal 80 uses RSVP to secure the network resource, and updates the network resource reservation information in the resource reservation table 15 based on the result, and the updated network resource reservation information. Is sent to the management device 20. Then, the management apparatus 20 deletes the unnecessary network resource of “reservation ID” = “2” in FIG. 19C in accordance with the network configuration change, and notifies that “reservation ID” = “2”. To the terminal indicated by the “source” MAC address and the terminal indicated by the “destination” MAC address. Then, a new “reservation ID” = “3” shown in FIG. 20 is to be secured for the route indicated by the arrow N21 in FIG.

  At this time, “reservation ID” = “3” shares the path between the repeater 50 and the repeater 70 with “reservation ID” = “1” that has already been reserved. If the network resource management unit 26 permits sharing, the reserved bandwidth “reservation ID” = “1” and the reserved bandwidth 6 Mbps of “reservation ID” = “3” to be newly reserved are set to 6 Mbps. Since the sum of 12 Mbps exceeds the bandwidth of 10 Mbps in this route, congestion occurs in this route. As a result, the network resource management unit 26 does not permit a new “reservation ID” = “3” reservation. This new reservation is secured after the communication of “reservation ID” = “1” is completed and the path between the repeater 50 and the repeater 70 is released.

  Thus, in the communication system of this embodiment, congestion on the network is always avoided.

  The data storage format of the resource reservation table 15 and the network resource management table 25 shown in FIG. 19 and the data storage format of the network resource management table 25 shown in FIG. 20 are examples, and in short, a simple identification number. As long as the network resource is reserved, the source, the destination, the route, and the reserved bandwidth can be identified, and the network resource can be managed by the information.

  Next, FIG. 21 is a flowchart showing a processing process in the communication system of the present embodiment. Referring to FIG. 18, a processing process in the communication system of the present embodiment from when a new connection is made until network resources are updated will be described according to FIG. 21.

  In step 11, the terminal 80 moves and is connected to a new port. Next, in step 12, the link state detection unit 13 of the terminal 80 detects a new link up.

  In step 13, the terminal 80 acquires resource reservation information of a newly required network resource and stores it in the resource reservation table 15.

  In step 14, the change notification unit 14 transmits the resource reservation information stored in the resource reservation table 15 to the management device 20.

  In step 15, the network resource management unit 26 of the management apparatus 20 creates reservation availability information that determines whether or not a new requested network resource can be reserved. The network resource management unit 26 updates the network resource reservation information in the network resource management table 25 on the basis of the created reservation availability information, and at the same time, sets the reservation availability information as the terminal indicated by the MAC address of the “source”. Notification is made to the terminal indicated by the “destination” MAC address.

  In step 16, the network resource management unit 26 waits for a predetermined time, and then returns control to step 12 to check whether there is a new link up.

  If a new link-up is detected in step 12, the processing from step 13 to step 15 is performed. If no new link-up is detected, the control is transferred to step 16.

  As described above, the communication system according to the present embodiment manages the network while detecting whether or not there is a new link-up every certain time.

  The terminal 80 according to the present embodiment described above is assumed to transmit a link detection notification incorporated in a link change notification dedicated packet when link up is detected.

  However, as in the first embodiment of the present invention, in this embodiment as well, this link detection notification may not use a link change notification dedicated packet. That is, each terminal and the management device promise in advance alternative information for link change notification, and the terminal can notify that the link has been changed by transmitting an alternative packet including the alternative information. I can do it.

  For example, instead of sending a link change notification dedicated packet, the terminal may perform so-called ping and send a substitute packet including an ICMP message as substitute information. Alternatively, when the terminal is a server or the like, it is possible to notify that the link has been changed by transmitting a substitute packet including service information that can be provided by the server as substitute information. Alternatively, when the terminal is an IP phone, it is possible to notify that the link has been changed by transmitting a substitute packet including the phone number information of the IP phone as substitute information. Furthermore, it is possible to notify that the link has been changed by transmitting network resource reservation information.

  As yet another example, another alternative packet in which a link change notification is incorporated in a part of the alternative information may be transmitted.

  Such an alternative packet is transmitted by broadcast or multicast.

  In this way, instead of transmitting the link change notification dedicated packet, the terminal and the management apparatus promise in advance alternative information of the link change notification and transmit the alternative packet including the alternative information. In this case, the transmission path is not occupied to transmit the dedicated packet.

(Third embodiment)
The communication system according to the third embodiment of the present invention includes a plurality of terminals 10 shown in FIG. 15 and one or more repeaters. An example of the communication system of this embodiment is obtained by omitting the management device 20 in FIG.

  Assuming that the management apparatus 20 of FIG. 18 is omitted, the operation of this embodiment will be described with reference to FIGS.

  In FIG. 18, it is assumed that the terminal 80 moves in the direction indicated by the arrow N20 and the connection is changed from the repeater 60 to the repeater 70. Then, the link state detection unit 13 of the terminal 80 detects a change in the link state, and the change notification unit 14 sends a notification that the network configuration has been changed to another terminal on the network (in this case, the terminal 90, terminal 100, and terminal 110). Further, the change notification unit 14 of the terminal 80 notifies the network resource reservation information stored in the resource reservation table 15 to other terminals on the network via the packet transmission unit 11.

  The change notification unit 14 of the terminal 80 executes RSVP based on the network resource reservation information stored in the resource reservation table 15 and secures network resources.

  The above-described link state change notification and network resource reservation information notification are performed by multicast or broadcast.

  As described above, in the communication system according to the present embodiment, all the terminals always share the current network configuration information and the network resource reservation information without installing the management device 20. However, it can manage the network from an equal position.

  Of course, in this embodiment, as in the first embodiment or the second embodiment of the present invention, the link change notification dedicated packet is not used for transmission of the new link up detection notification. An alternative packet may be used.

  The communication system of this embodiment is preferable as a small-scale and simple communication system.

  As described above, the present invention detects a new link-up when a terminal moves, and based on this information, immediately updates the network configuration information and tries to use network resources effectively. However, various applications are possible without departing from the spirit of the present invention.

  The communication system according to the present invention can be suitably used, for example, in the field of guaranteeing network resource reservation.

The block diagram of the terminal in the 1st Embodiment of this invention Block diagram of the management device (A) Connection diagram of the relay device (b) State diagram of the MAC address table Example of configuration information (A) Connection diagram of the relay device (b) State diagram of the MAC address table (A) Connection diagram of the relay device (b) State diagram of the MAC address table (c) Structure diagram of the packet (A) Connection diagram of the relay device (b) State diagram of the MAC address table (c) State diagram of the MAC address table (A) Connection diagram of the relay device (b) State diagram of the MAC address table (c) State diagram of the MAC address table Illustration of the network Example of IP address and MAC address (A) State diagram of the MAC address table (b) State diagram of the MAC address table (c) State diagram of the MAC address table Flow chart showing the process Communication procedure explanatory diagram (A) State diagram of the MAC address table (b) State diagram of the MAC address table (c) State diagram of the MAC address table The block diagram of the terminal in the 2nd Embodiment of this invention Block diagram of the management device Example of path on the network Example of path on the same network 2 (A) State diagram of the network resource management table (b) State diagram of the resource reservation table (c) State diagram of the resource reservation table State diagram of the network resource management table Flow chart showing the process Example of a path on a conventional network 1 Example of path on conventional network

Explanation of symbols

1, 2, 3, 4, 10, 80, 90, 100, 110 Terminals 5, 6, 7, 50, 60, 70 Repeater 11, 21 Packet transmitter 12, 22 Packet receiver 13 Link status detector 14 Change Notification unit 15 Resource reservation table 20 Management device 23 Information acquisition unit 24 Configuration information generation unit 25 Network resource management table 26 Network resource management unit 50, 60, 70 Relay devices 59, 69, 79 MAC address tables P1, P2, P3, P4 , P5, P6 pass

Claims (26)

A plurality of relay devices;
Among the relay devices, a terminal connected to any port of one relay device;
A management device having a configuration information generation unit configured to generate network configuration information, which is configured by the relay device and the terminal;
The relay device includes a plurality of ports,
A MAC address table for storing information of the source MAC address for each of these ports,
The terminal
A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
When the link state detection unit detects a link up, the communication system includes a change notification unit that notifies the management apparatus that the network configuration has been changed using the packet transmission unit. The communication system according to claim 1, wherein the notification is performed by transmitting a link change notification dedicated packet. The communication system according to claim 1, wherein the notification is performed by transmitting an alternative packet other than the link change notification dedicated packet. 4. The communication system according to claim 3, wherein the notification by the substitute packet transmits any one of an ICMP message, service information that can be provided by the terminal, and telephone number information of the terminal. The communication system according to claim 1, wherein the notification is performed by multicast and / or broadcast. The management device includes an information acquisition unit that, when receiving a notification from the terminal, acquires information on a MAC address related to each port from the relay device;
The communication system according to claim 1, wherein the configuration information generation unit updates network configuration information based on information acquired by the information acquisition unit. The communication system according to claim 6, wherein the information acquisition unit acquires information on a MAC address using SNMP. The communication system according to any one of claims 6 to 7, wherein the information acquisition unit acquires MAC address information only from a relay device existing on a route from a port related to a terminal that has made a notification to the management device. A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
When the link state detection unit detects a link up, the terminal includes a change notification unit that notifies the management device that the network configuration has been changed using the packet transmission unit. The terminal according to claim 9, wherein the network configuration change notification is performed by multicast and / or broadcast. A plurality of relay devices;
A terminal connected to any one port of one relay device among the relay devices,
The terminal
A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
A resource reservation table for storing network resource reservation information between the own terminal and other terminals;
When the link state detection unit detects a link up, a change notification unit that notifies the network resource reservation information stored in the resource reservation table to other terminals of the network using the packet transmission unit. A communication system. The communication system according to claim 11, wherein the notification of the network resource reservation information is performed by multicast and / or broadcast. The communication system according to claim 11, wherein the notification of the network resource reservation information is performed only to a communication partner terminal stored in the resource reservation table. 14. The communication system according to claim 11, wherein securing of network resources based on the network resource reservation information is performed by RSVP. A plurality of relay devices;
Among the relay devices, a terminal connected to any port of one relay device;
A network resource management table for storing network resource reservation information of a network constituted by the relay device and the terminal, and a management device having a network resource management unit for managing network resources,
The terminal
A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
A resource reservation table for storing network resource reservation information between the own terminal and other terminals;
When the link state detection unit detects a link up, the link state detection unit includes a change notification unit that notifies the management device of the network resource reservation information stored in the resource reservation table using the packet transmission unit. ,Communications system. In the management device, the network resource management unit creates reservation availability information for determining whether or not to reserve a network resource requested by the terminal for the network resource reservation information received from the terminal, and The communication system according to claim 15, wherein the network resource reservation information in the network resource management table is updated based on reservation availability information, and the reservation availability information is notified to the terminal and a communication partner terminal of the terminal. A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
A resource reservation table for storing network resource reservation information between the own terminal and other terminals;
When the link state detection unit detects a link up, a change notification unit that notifies the network resource reservation information stored in the resource reservation table to other terminals of the network using the packet transmission unit. A terminal. The terminal according to claim 17, wherein the notification of the network resource reservation information is performed by multicast and / or broadcast. A plurality of relay devices;
Among the relay devices, a terminal connected to any port of one relay device;
A management device configured to manage a network, configured by the relay device and the terminal;
The relay device is
Multiple ports,
A MAC address table storing a source MAC address for each of these ports,
The terminal
A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
A link state detection unit for detecting a link up to the relay device;
A resource reservation table for storing network resource reservation information between the own terminal and other terminals;
A change notification unit that notifies the management device that the configuration of the network has been changed and the network resource reservation information;
The management device
A packet receiver for receiving packets;
A packet transmitter for transmitting packets;
An information acquisition unit that acquires MAC address information about each port from the relay device;
A configuration information generator for generating configuration information of the network;
A network resource management table storing network resource reservation information of the network; and
A network resource management unit for managing network resources of the network,
In the terminal, when the link state detection unit detects a link up, a notification that the network configuration has been changed and network resource reservation information stored in the resource reservation table are sent to the packet transmission unit. Use to send to the manager,
In the management device, when the notification from the terminal is received, the information acquisition unit acquires the MAC address information regarding each port from the relay device, and the configuration information generation unit acquires the information acquired by the information acquisition unit. The network configuration information is updated based on the network resource management unit, and the network resource management unit determines whether or not to reserve the network resource requested by the terminal with respect to the network resource reservation information received from the terminal. And updating the network resource reservation information in the network resource management table based on the reservation availability information, and notifying the reservation availability information to the terminal and a communication partner terminal of the terminal. The communication system according to claim 19, wherein the notification is performed by transmitting a link change notification dedicated packet. The communication system according to claim 19, wherein the notification is performed by transmitting an alternative packet other than the link change notification dedicated packet. The communication system according to claim 21, wherein the notification by the substitute packet transmits one of an ICMP message, service information that can be provided by the terminal, telephone number information of the terminal, and network resource reservation information. The communication system according to claim 19 to 22, wherein the notification is performed by multicast and / or broadcast. The communication system according to claim 19, wherein the information acquisition unit acquires information of a MAC address using SNMP. The communication system according to claim 19, wherein the information acquisition unit acquires MAC address information only from a relay device existing on a path from a port related to a terminal that has made a notification to the management device. The said relay apparatus is a base station which comprises wireless LAN, The said link state detection part of the said terminal detects the change of the connection with the said base station as a link up, The Claims 1-8 and the Claim 11 The communication system according to claim 16 and claims 19 to 25.

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