JP2008147925A - Network band reservation method and communication equipment for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide communication equipment for a communication system capable of judging in an autonomous distributed manner whether a line of a desired band can be reserved in a desired time zone. <P>SOLUTION: The communication equipment is provided with: a means for storing link information and reservation information showing a reservation time zone and its reservation band of each reservation line to a link, determining a route up to communication equipment of a line set destination on the basis of the link information during reserving a line and notifying communication equipment on the determined route about a reservation time zone and a reservation band of a reservation line; a means for judging whether the reservation band can be ensured in a notified reservation time zone on the basis of the reservation information when receiving a notification of the reservation time zone and the reservation band of a reservation line from another communication equipment; and a means for adding the reservation time zone and the reservation band to the reservation information when receiving a message showing that all communication equipment on the route can ensure a reservation time zone in the reservation time zone. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for time-reserving a bandwidth of a packet-switched network or a circuit-switched network in an autonomous and distributed manner without using a single network management device or the like.

  Non-Patent Documents 1 to 4 describe a configuration in which line setting is performed in a packet switching network or a circuit switching network. For example, when an LSP (Label Switched Path) is set in an MPLS (Multi Protocol Label Switching) network, the node that is to perform the LSP setting refers to the link information database and calculates a route to the opposite end node of the LSP Then, a line setting request message including the route information and the required bandwidth is transmitted. When the node included in the route information receives the line setting request message, the node determines whether or not the required bandwidth can be secured from the current used bandwidth and the maximum available bandwidth. Forward the line setup request message to the specified node. In this way, the line setting request message is transferred in the order specified by the route information, and reaches the opposite node, which is the LSP termination point, when the bandwidth can be secured in all intermediate nodes. If the opposite node can also secure the bandwidth, the confirmation message is transferred in the reverse order to the route information, and the line setting is completed.

  Similarly, in a circuit-switched network, information indicating the required number of lines or bandwidth is transmitted and received between nodes that are termination points of the set line, and the required number of lines or bandwidth is secured in all nodes included in the circuit path. Line setup is completed when possible.

D. Katz et al, “Traffic Engineering (TE) Extensions to OSPF Version 2”, IETF RFC 3630, September 2003. D. Auduche et al, “RSVP-TE: Extensions to RSVP for LSP Tunnels”, IETF RFC 3209, December 2001. K. Kompella et al, “Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)”, IETF RFC4202, October 2005. L. Berger, “Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description”, IETF RFC3471, January 2003.

  In order to respond to requests for various network services, there are cases where it is desired to set up a line periodically from a certain time in the future or at a certain time zone. For this purpose, it is considered that the required bandwidth, start time, and end time if necessary for the line to be set are set in one node as a terminal point. In this case, the node serving as one of the terminal points transmits the line setting request message as described above at the set start time. This is not guaranteed, and therefore the line setting may fail, affecting service provision.

  Therefore, an object of the present invention is to provide a method for reserving a line having a desired bandwidth and setting a line reserved at a desired time, and a communication apparatus for the method. It is another object of the present invention to provide a method and a communication device that perform bandwidth reservation in an autonomous and distributed manner instead of using a single network management device in order to realize low cost and high reliability. .

The bandwidth reservation method in the present invention is:
A communication system including a plurality of communication devices and a link connecting each communication device, each communication device holding a link in the communication system as link information by exchanging information about the link to be connected, At least for the link to be connected, it is in a communication system that retains the reservation time zone of each line reserved for setting and the reservation information indicating the reserved band, and the communication apparatus that performs the line reservation sets the line to be reserved. The first step of determining the route to the communication device that is the destination based on the link information, and the communication device that performs the line reservation notify the communication device on the determined route of the reserved time zone and reserved bandwidth of the line to be reserved In the second step, and in each communication device on the route, a reserved bandwidth is secured in the notified reserved time zone for at least the link to be connected The third step of determining whether or not the reservation can be made, and if the reserved bandwidth can be secured in the reserved time zone in all communication devices on the route, the communication device that performs line reservation and each communication device on the route And a fourth step of updating the reservation information.

According to another embodiment of the bandwidth reservation method of the present invention,
Each communication device acquires reservation information of each link in the communication system by exchanging reservation information. In the first step, the communication device that performs line reservation is based on the link information and the reservation information of each link. It is also preferable to determine the route.

According to another embodiment of the bandwidth reservation method of the present invention,
In the second step, the communication device that performs the line reservation transmits a reservation request message including route information indicating the determined route, a reservation time zone, and a reserved bandwidth to the link on the route, and receives the reservation request message. However, it is also preferable to transfer the reservation request message in accordance with the included route information.

The bandwidth line reserved by the above method is
The communication device that made the line reservation transmits a reserved line setting request message indicating activation of the reserved line to the link on the route at the start of the reserved time zone, and the reserved line received in the communication device in the middle of the route In response to the reception of the reserved line setting request message, the reserved line setting confirmation message is transmitted to the link on the route at the step of transferring the setting request message in the order of the reserved line route and the reception of the reserved line setting request message. And a step of transferring the received reserved line setting confirmation message in the reverse order of the reserved line route in the communication device in the middle of the route, and transmitting / receiving the reserved line setting request message or transmitting / receiving the reserved line setting confirmation message. Sometimes it is also preferable to activate the reserved line.

The communication device in the present invention is
Means for acquiring information about a link in the communication system and holding it as link information, and at least a reservation time zone for each line reserved for setting and a reservation information indicating the reserved bandwidth for the link connected to the own device When a line is reserved with the means to hold, the route to the communication device of the line setting destination is determined based on the link information, and the reservation time zone and reserved bandwidth of the line to be reserved are notified to the communication device on the determined route If the first means and a notification of the reserved time zone and reserved bandwidth of the line to be reserved are received from another communication device, at least the link connected to the own device based on the reservation information, the reserved bandwidth in the notified reserved time zone A second means for determining whether or not a reservation can be secured, and a reservation time zone and a reservation bandwidth of a line to be reserved, or a reservation of a line to be reserved from another communication device When receiving the notification of the interband and reserved bandwidth, if all communication devices on the route receive a message indicating that the reserved bandwidth can be secured in the reserved time zone, the notified reserved time zone and reserved bandwidth are notified. And a third means for adding to the reservation information.

According to another embodiment of the communication device of the present invention,
It has means for exchanging reservation information with other communication devices in the communication system, and acquiring reservation information for each link in the communication system, wherein the first means includes a route to the communication device of the line setting destination It is also preferable to determine based on link information and reservation information of each link.

According to another embodiment of the communication device of the present invention,
The first means transmits a reservation request message including route information indicating the determined route, a reservation time zone, and a reservation bandwidth to the link on the route, and the second means is a reservation request in which the own device is included in the route. When the reserved bandwidth can be secured in the reserved time zone notified by the message, it is determined whether or not the own device is a communication device at the final position of the route. If not, the received reservation request message is routed. It is also preferable to transfer to the next communication device.

According to another embodiment of the communication device of the present invention,
When line reservation is made, at the start of the reserved time zone, a reserved line setting request message indicating activation of the reserved line is transmitted to the link on the route, and the reserved line setting of the reserved line in the middle of the own device When the request message is received, a means for transferring the received reserved line setting request message to the next communication device along the reserved line route and a reserved line setting request message for the reserved line at which the own device is at the final position of the route If received, the reserved line setting confirmation message is sent to the link on the route of the reserved line, and when the own device receives the reserved line setting confirmation message of the reserved line in the middle of the route, the received reserved line setting confirmation message is received. Means for transferring a message to a communication device located in the previous path of a reserved line, and at the time of transmission / reception of a reserved line setting request message or a reserved line Even and means to activate the reservation line when receiving the constant confirmation message preferable.

  When managing reservation information and making a line reservation in each communication device, it is possible to set a line having a reserved bandwidth in each communication device by notifying each communication device on the route of the reserved time zone and reserved bandwidth. It is possible to construct a distributed reservation system that does not use a centralized reservation system such as a reservation by a network management apparatus that controls all nodes. In addition, since the reservation time zone and the reservation band are notified to each communication device on the route by transferring the reservation message on the line route, the system can be changed by simply changing the communication device for setting the conventional line. Can be built. Further, by notifying the activation of the reserved line, it is possible to quickly determine whether or not the line setting has been successfully performed at the start of the reservation time.

  Further, each communication device exchanges reservation information and acquires reservation information for each link in the communication system, so that the reservation status of each link can be taken into account in determining the route when making a line reservation. Can be used effectively.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a system configuration diagram according to the present invention. The system according to the present invention includes a communication device (hereinafter referred to as a node) according to the present invention, nodes 10 to 15 in FIG. 1, a communication link (hereinafter referred to as a link) connecting the nodes, and a link in FIG. 20 to 27 are included.

  FIG. 2 is a block diagram of a node according to the present invention. According to FIG. 2, the node includes a link information processing unit 101, a reservation processing unit 102, a line setting control unit 103, a time synchronization unit 104, and a storage unit 105, and the storage unit 105 includes link information 106. And reservation information 107 are held.

  FIG. 3 is a diagram showing the link information 106 and the reservation information 107 held by the storage unit 105. The link information 106 is information about each link in the system, and specifically includes information about a node that terminates the link, its interface, and the bandwidth of the link. The link information 106 shown in FIG. 3A indicates that one end of the link 20 is accommodated in the interface # ID1 of the node 10 and the other end is accommodated in the interface # ID3 of the node 11. Here, for the identification of an interface, a combination of an IP address assigned to the interface or a node address unique in the network and an interface identifier is used. Further, the maximum bandwidth of the link 20 is 1 Gbps, and the maximum value of the currently reserved bandwidth is 900 Mbps, that is, 100 Mbps is currently free in the future.

  The reservation information 107 is information indicating the reservation state of each link, and includes a reservation identifier for identifying each reservation and its reservation content. The reservation content includes the bandwidth of the reserved line and the reservation time zone, for example, start Includes time and end time. In the reservation information 107 shown in FIG. 3B, a bandwidth of 100 Mbps is reserved as a reservation identifier 1 from 10 o'clock to 16 o'clock on October 30, 2006 for the link 20, and from 18 o'clock on October 29, 2006. It shows that 200 Mbps is reserved as the reservation identifier 2 at 18 o'clock on October 31, 2006. With this reservation information, it becomes possible to recognize the transition of the reserved bandwidth from the present to the future shown in FIG. 4 for each link. When line setting is performed at a future time and the line is maintained without being disconnected, the end time is set to a value indicating no end. In addition, when a line is periodically set in a fixed time zone, the information included in the reservation content is not limited to the information shown in FIG. 3, such as including information indicating start time and end time and repetition in the reservation content. .

  Returning to FIG. 2, the link information processing unit 101 creates and updates the link information 106 by exchanging messages including link information with other apparatuses. Various routing protocols can be used to exchange link information. As will be described later, the reservation processing unit 102 creates and updates the reservation information 107 by exchanging a message including information about the line to be reserved with other nodes, and activates the reserved line. A line setting instruction is given to the control unit 103. Further, when the reserved line is explicitly activated, a message including information on the reserved line is exchanged with another node when the reserved line is activated. When the line setting control unit 103 receives a line setting instruction from the reservation processing unit 102, for example, when the node is a cross-connect, the connection setting process between links, and when the node is an MPLS router, to the activated path Necessary line setting processing such as labeling for the IP packet to be transmitted is performed.

  FIG. 5 is a sequence diagram of line reservation. The reservation processing unit 102 calculates a route to the node device at the other end of the line based on the link information 106 when the necessity of reservation of the line occurs, such as a command input from the maintenance person, and based on the reservation information 107, It is determined whether or not the reserved bandwidth can be secured in the reserved time zone in at least the link that terminates itself in the links on the route. If the reserved bandwidth can be secured, a message requesting line reservation, that is, a line reservation request message To a link that uses as a route. As will be described later, the line reservation request message is used for setting a line that differs depending on the node type, such as information indicating a reserved time zone, information indicating a reserved band, route information, a reservation identifier for identifying these reserved lines, and the like. Contains the parameters.

  In addition, when a line reservation request message is received from another node, the reservation processing unit 102 determines whether or not the own node is included in the route specified by the route information. Based on 107, it is determined whether or not the reserved bandwidth can be secured in the reserved time zone in at least the link on the route where the own device terminates. If the reserved bandwidth can be secured in the reserved time zone, and the local node is an intermediate node on the route specified by the route information and is not the final position, the circuit reservation request message is transferred to the next node in the route information .

  On the other hand, if the reserved bandwidth can be secured in the reserved time zone and the own node is the last node specified by the route information, it means that the bandwidth can be secured in all nodes on the route, so the reservation information 107 is updated. That is, the reservation time zone and the reservation bandwidth are added to the reservation information 107, and a message indicating that the line has been reserved, that is, a line reservation confirmation message is transmitted to the received link. The line reservation confirmation message includes route information in which the route information included in the received line reservation request message is specified in reverse order, and the same route as the line reservation request message is transferred in the reverse direction. .

  Further, when the reservation processing unit 102 receives a line reservation confirmation message included in the route information from another node, the reservation processing unit 102 can recognize from this message that the bandwidth can be secured in all the nodes on the route. Update. Furthermore, it is determined whether the own node is a node in the middle of the route or the last node, and if it is a node in the middle of the route, a line reservation confirmation message is transferred to the next node according to the route information. Finally, the circuit reservation confirmation message arrives at the node that transmitted the circuit reservation request message, and the circuit reservation process is completed.

  FIG. 5 shows a line reservation sequence in a case where the node 10 sets the node 13 as a setting destination and reserves a line passing through the nodes 11 and 12.

  FIG. 6 is a sequence diagram for activating a reserved line, that is, for making it active. The reservation processing unit 102 sends a reserved line setting request message for requesting activation of the reserved line, that is, activation, for the reserved line for which the own apparatus has requested the line reservation, using the reserved line route. Send to a link. As will be described later, this reserved line setting request message includes information indicating the reserved time zone, information indicating the reserved band, route information indicating the route of the reserved line, and a reservation identifier for identifying these reserved lines. Yes.

  The reserved line setting request message is sequentially transferred through the nodes according to the included route information, and arrives at the node where the reserved line is set. The reservation processing unit 102 of the reserved line setting destination node instructs the line setting control unit 103 to set the line of the corresponding reserved line and notifies the reserved line setting, that is, a reserved line setting confirmation message. Is transmitted to the link that has received the reserved line setting request message. The reserved line setting confirmation message includes the route information included in the reverse order of the route information included in the received reserved line setting request message, and the same route as the reserved line setting request message is reversed. It will be transferred.

  The reservation processing unit 102 of the node on the route that has received the reserved line setting confirmation message instructs the line setting control unit 103 to set the line of the corresponding reserved line, and transfers the reserved line setting confirmation message according to the included route information. . Finally, the reserved line setting confirmation message arrives at the node that sent the reserved line setting request message, and the reservation processing unit 102 of the node that sent the reserved line setting request message sends the reserved line setting message to the line setting control unit 103. The reservation line is activated by instructing the setting.

  FIG. 6 shows a sequence when the node 10 activates a line that reaches the node 13 via the reserved nodes 11 and 12. Note that a line setting instruction may be given to the line setting control unit 103 when a reserved line setting request message is transmitted and received.

  FIG. 7 is a configuration diagram of a line reservation request, a line reservation confirmation, a reserved line setting request, and a reserved line setting confirmation message. In FIG. 7, the reservation flag field is a field indicating the message type, that is, whether the message is a line reservation request, a line reservation confirmation, a reserved line setting request, or a reserved line setting confirmation, and the reservation identifier field identifies a reservation. The disclosure time and end time fields are reserved time zones, the reserved bandwidth field is a requested bandwidth, and the route information field is a field indicating the route of the line to be set. When the reserved line is activated, the start time, end time, and reserved bandwidth field can be omitted because the identifier can identify the start time, end time, and reserved bandwidth.

  Note that the time information of each node needs to be the same for the consistency of the reservation process, and the time synchronization unit 104 is provided for this purpose. Specifically, the time synchronization unit 104 acquires time information from a node having a reference time in the network using a protocol such as NTP (Network Timing Protocol). Note that the time information may be matched by another method. In addition, when the time information is accurately matched in each node, the exchange of the reserved line setting request and the reserved line setting confirmation message is omitted, and each node activates the reserved line independently based on the reserved information 107. You can go.

  Preferably, the reservation processing unit 102 exchanges the reservation information 107 with another node, and each node acquires the reservation information 107 for each link in the system. Each node acquires the reservation information 107 for each link in the system, so that when the line reservation is made, the reservation processing unit 102 can determine the route in consideration of the reservation status of each link, and the bandwidth is effective. Can be used. Various routing protocols can be used for exchanging the reservation information 107.

  Further, in the above-described embodiment, the line setting destination node specifies a route in which the route included in the received line reservation request message or reserved line setting request message is specified in reverse order in the line reservation confirmation message or reserved line setting confirmation message. It was set, but when a line reservation request message or reserved line setting request message was transferred at a node in the middle of the route, it was memorized from which node it was received, and a line reservation confirmation message or reserved line setting was stored. When the confirmation message is received, the confirmation message may be transferred to the stored node. In this case, the route information field of the line reservation confirmation message and the reserved line setting confirmation message can be omitted.

  As described above, the reservation processing unit 102 creates and updates the reservation information 107 in each node, and a message indicating reservation processing, a reservation time zone, and a band in a message for line setting in the conventional technology such as RSVP By including the information about, it is possible to determine whether or not it is possible to secure the bandwidth in the reservation time zone at each node, without using a centralized reservation system such as reservation by a network management device that controls all nodes, A distributed reservation system can be constructed with simple changes to existing devices.

1 is a system configuration diagram according to the present invention. 1 is a block diagram of a communication device according to the present invention. It is a figure which shows link information and reservation information. It is a figure which shows transition of the time obtained from reservation information, and a reservation zone | band. It is a sequence diagram for line reservation. It is a sequence diagram for activation of a reserved line. It is a block diagram of each message.

Explanation of symbols

10, 11, 12, 13, 14, 15 Nodes 20, 21, 22, 23, 24, 25, 26, 27 Link 101 Link information processing unit 102 Reservation processing unit 103 Line setting control unit 104 Time synchronization unit 105 Storage unit 106 Link information 107 Reservation information

Claims (8)

A communication system including a plurality of communication devices and a link connecting each communication device, each communication device holding a link in the communication system as link information by exchanging information about the link to be connected, In a communication system that holds reservation information indicating a reserved time zone and a reserved bandwidth of each line reserved for setting at least for a link to be connected,
A first step in which a communication device that performs line reservation determines a route to a communication device that is a setting destination of a line to be reserved based on link information;
A second step in which a communication device that performs line reservation notifies a communication device on the determined route of a reservation time zone and a reservation bandwidth of a line to be reserved;
A third step of determining, based on the reservation information, whether or not the reserved bandwidth can be secured in the notified reservation time zone for at least the link to be connected in each communication device on the path;
A fourth step of updating reservation information in a communication device that makes a line reservation and each communication device on the route when the reserved bandwidth can be secured in all the communication devices on the route; and
Band reservation method with Each communication device acquires reservation information of each link in the communication system by exchanging reservation information,
The method according to claim 1, wherein in the first step, a communication apparatus that performs line reservation determines a route based on link information and reservation information of each link.   In the second step, the communication device that performs the line reservation transmits a reservation request message including route information indicating the determined route, a reservation time zone, and a reserved bandwidth to the link on the route, and receives the reservation request message. The method according to claim 1 or 2, wherein the method is performed by transferring a reservation request message in accordance with the included route information. A method for activating a reserved bandwidth line by the method according to any one of claims 1 to 3,
A communication device that has made a line reservation transmits a reserved line setting request message indicating activation of the reserved line to a link on the route at the start of the reserved time period; and
In the communication device in the middle of the route, a step of transferring the received reserved line setting request message in the order of the reserved line route;
In the communication device that is the setting destination of the reserved line, in response to reception of the reserved line setting request message, a step of transmitting a reserved line setting confirmation message to the link on the route;
In the communication device in the middle of the route, a step of transferring the received reserved line setting confirmation message in the reverse order of the route of the reserved line;
Have
A method of activating a reserved line when a reserved line setting request message is transmitted / received or when a reserved line setting confirmation message is transmitted / received. Means for obtaining information about a link in the communication system and holding it as link information;
Means for holding at least a reservation time zone of each line reserved for setting and a reservation information indicating the reserved bandwidth for a link connected to the own device;
When reserving a line, a route to a communication device that is a line setting destination is determined based on link information, and a communication device on the determined route is notified of a reserved time zone and a reserved bandwidth of a line to be reserved; ,
Whether or not the reserved bandwidth can be secured in the notified reservation time zone for at least the link connected to the own device based on the reservation information when receiving notification of the reserved time zone and reserved bandwidth of the line to be reserved from another communication device A second means for determining
When the reserved time zone and reserved bandwidth of the line to be reserved are notified, or when the notification of the reserved time zone and reserved bandwidth of the line to be reserved is received from another communication device, all the communication devices on the route When a message indicating that the reserved bandwidth can be secured is received, a third means for notifying or adding the notified reserved time zone and reserved bandwidth to the reserved information;
A communication device comprising: Exchanging reservation information with other communication devices in the communication system, and having means for acquiring reservation information for each link in the communication system;
6. The communication apparatus according to claim 5, wherein the first means determines a route to a communication apparatus that is a line setting destination based on link information and reservation information of each link. The first means transmits a reservation request message including route information indicating the determined route, a reservation time zone and a reservation bandwidth to a link on the route,
The second means determines whether or not the own device is a communication device at the final position of the route when the reserved bandwidth can be secured in the reserved time zone notified by the reservation request message included in the route. If it is not the final position, the received reservation request message is transferred to the next communication device along the route.
The communication apparatus according to claim 5 or 6. A means for sending a reserved line setting request message indicating activation of the reserved line to a link on the route at the start of the reserved time period when the line reservation is made;
Means for transferring the received reserved line setting request message to the next communication device in the reserved line path when the own apparatus receives the reserved line setting request message of the reserved line in the middle of the path;
Means for transmitting a reserved line setting confirmation message to a link on the route of the reserved line when the device receives the reserved line setting request message of the reserved line at the final position of the route;
Means for transferring the received reserved line setting confirmation message to a communication device located in the path of the reserved line when the own apparatus receives the reserved line setting confirmation message of the reserved line in the middle of the path;
Means for activating a reserved line at the time of transmission / reception of a reserved line setting request message or transmission / reception of a reserved line setting confirmation message;
The communication device according to any one of claims 5 to 7, further comprising:

Images