JP4328312B2 - VPN service providing method and optical path establishment method - Google Patents

Description

  The present invention relates to a VPN service providing method and an optical path establishing method in an optical network.

OXC switch (Optical Cros) is a technology for economically increasing the capacity of core networks.
s Connect switches, optical cross-connect switches) and TDM switches (Time Division Multiplexing switches, time division multiplexing switches), IP (Internet Protocol) control of optical paths such as layer 1 wavelengths and TDM channels GMPLS (Generalized Multi-Protocol Label Switching) controlled using signals has been proposed (see Prior Art Document 1).

  Furthermore, taking advantage of the ability to flexibly establish and release optical paths using control signals, cut-through that automatically establishes and releases optical paths according to the amount of traffic between the ground (between bases). Technology has also been proposed (see Prior Art Documents 2 and 3).

  Currently, as a communication service for enterprises, an IP-VPN (Internet Protocol-Virtual Private Network) service for connecting multiple sites of an enterprise with IP (Internet Protocol), and similarly, an Ethernet (registered trademark) between multiple sites is used. Wide-area Ethernet (registered trademark) service (layer 2 VPN service) connected by the network is the mainstream.

In these services, since the packets of a plurality of users are multiplexed in the core network portion, the bandwidth can be used efficiently. In addition, since communication between all bases is basically possible in the core network portion, a user who uses the base network only needs to design the bandwidth of the access line, and there is no need to consider traffic between the bases. Therefore, there is an advantage that the user can easily design the entire network.
Eric Mannie (Editor), "Generalized Multi-Protocol Label Switching Architecture" (IETF Internet Standard), [online], Oct. 2004, IETF, [March 10, 2005 search], Internet <URL: http: // www.ietf.org/rfc/rfc3945.txt> Hisashi Kojima, Ichiro Inoue, Tomonori Takeda, “Multilayer Linkage Method in Optical + IP Network”, Information Processing Society of Japan, Information and Communication Society Information and Science Technology Forum Proceedings, L-009, September 2003 Hisashi Kojima, Takashi Kurimoto, Ichiro Inoue, "A Study on Optical Cut-Through Method Considering Inter-AS Optical Path", IEICE 2005 General Conference, b-6-135, March 2005

  With the spread of IP-VPN and wide-area Ethernet (registered trademark) and the increase in bandwidth usage per user, the core network that provides these services is replaced with an optical network, and GMPLS is applied to increase the capacity and economy. It is considered to realize the system.

However, since the optical network is a path-based network, it is necessary to set a path for connection between bases. Since the path here is fixedly set between the bases, it is necessary to estimate the traffic between the bases in advance, and to match the peak band used by the user. Since the path is fixedly set in this way, for the VPN operator, there is a problem that the use efficiency of the resources of the optical network does not increase, and charging can be made only at a fixed amount, that is, charging according to the amount of traffic of the user. There was a problem that I could not. In addition, when the traffic volume of the VPN service user increases only temporarily, the user has to make a contract in accordance with the peak bandwidth, and there is a problem that the charge for using the VPN service is increased.
An object of the present invention is to provide a VPN service providing method and an optical path establishing method for solving the above-described problems.

  A VPN service providing method for connecting each base of a user through a VPN via an optical network, wherein an edge node of the optical network connected to the base user network is fixed between other edge nodes. Establishing an optical path, measuring a traffic amount between the other edge nodes, and when the measured traffic amount exceeds a predetermined threshold stored in the storage unit of the edge node, Establishing an additional optical path for an edge node that is a destination of traffic exceeding the predetermined threshold; a user ID of the VPN service allocated to the user network; and an optical path of the established additional optical path Transmitting an additional optical path establishment notification including an ID and bandwidth information of the additional optical path; A step of receiving a notification of establishment of the additional optical path from the edge node by a usage record server of the VPN service comprising a usage record database indicating the usage record of the additional optical path for each user ID; and the received additional optical path The method of executing the step of recording the path establishment notification in the usage record database.

  According to the above-described method, the minimum connectivity between user networks (user sites in the embodiment) is secured by a fixed optical path, and when the traffic volume between user networks increases, an edge node Establish an additional optical path. This eliminates the need for VPN service users to perform path-based network design. That is, a VPN service using a large-capacity optical network can be used in the same way as a packet-based VPN service. In addition, since the usage record server records the user ID of the user who uses the additional optical path and the bandwidth of the additional optical path, the VPN operator refers to this information to establish and connect to the additional optical path. It is possible to charge the user of the user network according to the usage bandwidth of the additional optical path.

  The VPN service providing method according to claim 1, wherein the edge node releases the established additional optical path when the measured traffic amount is equal to or less than the predetermined threshold value. A step of transmitting an additional optical path release notification including the user ID allocated to the user network and the optical path ID of the released additional optical path, wherein the usage recording server is configured to transmit the edge Receiving the additional optical path release notification from the node; based on the received additional optical path establishment notification and the additional optical path release notification received; bandwidth information of the additional optical path established; and the additional optical path The step of executing the step of writing the establishment time and release time in the usage record database.

  According to the method described above, the usage recording server records the bandwidth of the additional optical path and the establishment time and release time of the additional optical path. Therefore, by referring to this information, the VPN operator can charge the user for a usage-based charge according to the bandwidth and time of use of the additional optical path (time from establishment to release of the optical path).

  Further, the present invention provides an optical path establishment method in the VPN service providing method according to claim 1 or 2, wherein the edge node is configured to establish the additional optical path before the edge node establishes the additional optical path. For each user ID of the VPN service, an additional optical path including at least the user ID and the bandwidth of the additional optical path in a policy server including a policy database indicating an upper limit value of a bandwidth that can be set for the additional optical path. A step of transmitting an establishment request, wherein the policy server refers to the policy database and the transmitted establishment request for the additional optical path, and the bandwidth of the additional optical path that is the target of the establishment request is A step of transmitting a response to allow establishment of the additional optical path to the edge node when it is determined that the value is less than or equal to an upper limit value. The edge node, when receiving the response of established authorization of the additional optical path, and a method of performing the establishment of the additional optical path.

  Also, the present invention provides the optical path establishment method according to claim 3, wherein the policy server is a target of the establishment request with reference to the policy database and the transmitted establishment request for the additional optical path. When it is determined that the bandwidth of the additional optical path exceeds the upper limit value, a step of transmitting a response indicating that the additional optical path cannot be established is transmitted to the edge node, and the edge node establishes the additional optical path. A method is adopted in which the establishment of the additional optical path is not executed when an impossible response is received.

  According to the method described above, in the optical network, the upper limit value of resources (bandwidth) allocated for each user can be set in advance by a contract or the like. Therefore, it is possible to avoid a specific user from occupying resources in the optical network or being charged due to excessive use of resources. In addition, since the VPN operator can grasp the amount of resources that the user may use in advance by referring to the information in the policy database, the VPN operator can plan and efficiently install the facilities. Can be expanded.

  Further, the present invention provides an optical path establishment method according to claim 3 or 4, wherein an edge node establishes and releases an optical path using a GMPLS (Generalized Multi-Protocol Label Switching) protocol. did.

  According to the above-described method, it is possible to easily establish and release an optical path as compared with a case where manual setting is performed on an edge node (edge router) or OXC of an optical network. As a result, when the traffic status of the edge node increases, the edge node can immediately establish an optical path (additional optical path), so that communication can be continued without causing congestion. Accordingly, the VPN provider can provide an optical path that responds to traffic demands, and can efficiently use resources. The user can also receive a high-quality VPN service.

  Further, the present invention provides the optical path establishment method according to any one of claims 3 to 5, wherein the edge node is a router using an IP (Internet Protocol) protocol. did.

  According to the above-described method, in the IP-VPN service, even when the backbone (core network) is an optical network, the same usability as that of the conventional packet-based IP-VPN service can be provided to the user.

  According to the present invention, it is not necessary for a VPN operator to set an optical path in accordance with a peak bandwidth in a VPN service using an optical network. In addition, the optical resources of the optical network can be efficiently used, and the metered charge according to the bandwidth of the additional optical path of the user of the VPN service can be made. Furthermore, since the VPN service user does not need to make a contract in accordance with the peak bandwidth, the usage fee for the VPN service can be reduced.

  The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. In the present embodiment, a case where user sites (user networks) of a certain user are connected by IP-VPN will be described as an example.

  Here, the control protocol of the optical network 1 is GMPLS, and the policy server 9 (described later) has an optical path topology for each user ID of the VPN service in the storage unit and a cut-through path bandwidth additionally set for this optical path. Stores information related to the upper limit value (resource upper limit value). This cut-through path corresponds to the additional optical path in the claims. The user ID of the VPN service is assigned to the same user ID for the user site of the same user.

  In the following description, the policy server 9 is described as using the upper limit value of the band as the resource upper limit value. However, the upper limit value of the number of cut-through paths may be used instead.

FIG. 1 is a diagram showing a network configuration of the present embodiment.
The network configuration of this embodiment will be described with reference to FIG. The optical network 1 includes an edge router 2 that is an edge of the optical network 1, that is, an end point of an optical path, and an OXC (optical cross-connect) 3 that can be switched in units of wavelength or optical fiber. The edge router 2 corresponds to an edge node in the claims.

The edge router 2 and the OXC 3 are facilities of a VPN provider, and it is assumed that these VPNs are buried and operated by the VPN provider. The edge router 2 and the OXC 3 have a routing protocol and a signaling protocol compliant with GMPLS, and establish and release an optical path by GMPLS through the GMPLS control plane 8.

  The edge router 2 connects a user site (user network) 4 with a CE router (customer edge router) 5 which is user equipment. In the present embodiment, a case where a certain user makes a VPN connection between four user sites 4 (sites A, B, C, and D) will be described as an example. That is, it is assumed that the sites A to D are networks (bases) of the same user, and the same user ID (for example, # 1) is assigned to the sites A to D. The edge router 2 and the CE router 5 are assumed to be IP routers corresponding to the IP protocol.

  In the optical network 1, a plurality of basic optical paths 6 are established in each edge router 2 so that the user sites 4 can communicate with each other by IP. The basic optical path 6 is a fixed optical path that connects the user sites 4 to each other, and at least the basic optical path 6 alone communicates with all edge routers 2, that is, all user sites 4 by IP. Is possible. In other words, the edge router 2 has established a minimum optical path (basic optical path 6) for communication between the user sites 4 in the optical network 1, and this basic optical path when the traffic volume increases. In addition to 6, a cut-through path 7 is established to secure a bandwidth. Incidentally, the edge router 2 does not release the basic optical path 6 even if the traffic volume between the user sites 4 decreases.

  In this embodiment, information on the upper limit bandwidths of the basic optical path 6 and cut-through path 7 with which the user contracts with the VPN operator is recorded in the policy server 9 in the GMPLS control plane 8. This policy server 9 communicates with each edge router 2 via the GMPLS control plane 8 and controls the edge router 2 not to establish a cut-through path 7 other than the contents contracted by the user.

  Specifically, when a contract regarding the VPN service is established between the user and the VPN provider, the VPN provider sends the policy server 9 the topology of the basic optical path 6, the bandwidth of the basic optical path 6, and the cut-through path 7 Record the information on the upper bandwidth limit of use. When the policy server 9 receives the request for establishing the cut-through path 7 from the edge router 2, the policy server 9 refers to the contents of the contract of the user and determines whether or not the cut-through path 7 can be established. Then, the judgment result is transmitted to the edge router 2, and when the edge router 2 receives the response that the cut-through path 7 can be established, the cut-through path 7 is established. On the other hand, when the response that the cut-through path 7 cannot be established is received, the cut-through path 7 is not established.

Further, in the GMPLS control plane 8, a usage record for recording the establishment time (use start date and time) and release time (use end date and time) of the cut-through path 7 established by each edge router 2, the bandwidth set for this path, and the like. A server 10 is installed. The VPN operator can know the usage time of each user's cut-through path 7 and the bandwidth set for this path by referring to the record of the usage record server 10. That is, the VPN company can charge the user for the usage fee of the VPN service according to the usage time of the cut-through path 7 and the bandwidth set for this path.
The information regarding the set time and release time of this cut-through path 7 and the bandwidth set for this path is obtained from the usage record server 10 from the edge router 2 to the policy server 9 when the edge router 2 establishes and releases the cut-through path 7. Receive via.

FIG. 2 is a block diagram illustrating the functional expansion of the edge router according to the present embodiment.
The function of the edge router 2 in FIG. 1 will be described using FIG. 2 with reference to FIG. Although not shown here, the edge router 2 includes a calculation means such as a CPU (Central Processing Unit), a RAM (Random Access Memory) that is a storage area for the calculation means to execute calculation processing, a ROM ( Read only memory), input / output interface, etc.

  The edge router 2 includes an optical path control processing unit 201 that establishes and releases an optical path, a traffic measurement unit 202 that measures the traffic amount of the edge router 2, and an edge router 2 that allows the edge router 2 to establish a cut-through path 7. The cut-through destination candidate list 203, the traffic measurement table 204, and the threshold 205 serving as a determination criterion when setting the cut-through path 7 are included.

  The optical path control processing unit 201 has a function of controlling establishment and release of an optical path. Specifically, a protocol for establishing and releasing an optical path such as GMPLS is operated to establish and release the cut-through path 7. A signal for establishing or releasing the cut-through path 7 is transmitted / received to / from the OXC 3 and other edge routers 2 via the GMPLS control plane 8. The cut-through destination edge router 2 selects from the cut-through destination candidate list 203.

  The traffic measurement unit 202 measures the traffic volume of the user site 4 (sites A to D). Specifically, when transferring a packet, the traffic measurement unit 202 refers to the traffic measurement table 204 and measures the traffic amount for each edge router 2 that passes therethrough.

  The cut-through destination candidate list 203 is information indicating an address of the cut-through destination edge router 2 that can be established by the edge router 2.

This traffic measurement table 204 shows the address (identification information) of the edge router 2 through which the identification information of the user site 4 is passed. Table 1 below illustrates the traffic measurement table 204.

  For example, in the traffic measurement table 204 of Table 1, the traffic addressed to “Site B” passes through “B (edge router 2B in FIG. 1)”, and the traffic addressed to “Site C” indicates “B, C (edge It is shown that the traffic addressed to “site D” via “router 2B, 2C)” goes via “B, C, D (edge router 2B, 2C, 2D)”. Note that, for example, the subnet set in the user site 4 may be written in the identification information column of the user site 4 in the traffic measurement table 204.

  The traffic measurement table 204 may be created by the edge router 2 using (1) OSPF (Open Shortest Path First) information, or (2) BGP (Border Gateway Protocol) route information. May be. For example, the creation of the traffic measurement table 204 according to (1) is realized by using the technique described in Non-Patent Document 2, and the creation of the traffic measurement table 204 according to (2) is realized by using the technique described in Non-Patent Document 3. Is possible.

  The traffic measurement unit 202 outputs data relating to the measured traffic volume to the optical path control processing unit 201. In response to this, the optical path control processing unit 201 determines whether or not the traffic amount output from the traffic measurement unit 202 exceeds the threshold value 205. Here, when the traffic amount in a predetermined time exceeds the threshold value 205, the optical path control processing unit 201 transmits a request for establishing the cut-through path 7 to the policy server 9 via the GMPLS control plane 8. Then, when a response of establishment (permission) of the cut-through path 7 is received from the policy server 9, the cut-through path 7 is established with the destination edge router 2. On the other hand, when the response of establishment OK (permission) of the cut-through path 7 is not received (when a response indicating that the cut-through path 7 cannot be established is received), the optical path control processing unit 201 does not establish the cut-through path 7.

  As described above, the threshold 205 is information indicating the traffic amount per predetermined time, which is a determination criterion when the edge router 2 establishes the cut-through path 7. The value of the threshold 205 may be set for each edge router 2 serving as a traffic destination, or may be set for each user site 4. Further, the value of the threshold 205 is set and inputted to the edge router 2 by the VPN operator via the network, for example.

  The cut-through destination candidate list 203, the traffic measurement table 204, and the threshold value 205 are stored in the storage unit of the edge router 2. The optical path control processing unit 201 and the traffic measurement unit 202 may be realized by a program execution process by the CPU of the edge router 2 or may be realized by dedicated hardware.

FIG. 3 is a block diagram showing a functional development of the configuration of the policy server of FIG.
The function of the policy server 9 of FIG. 1 will be described using FIG. 3 with reference to FIGS. The policy server 9 includes a CPU, a storage unit, an input / output interface, and the like, and is realized by a computer capable of IP communication.

  The policy server 9 includes a cut-through determination unit 901 that determines whether the edge router 2 can set the cut-through path 7, and a policy that indicates an upper limit value of a bandwidth that can be set in the cut-through path 7 for each user ID of the VPN service. It includes a database 903 and a cut-through path information update unit 902 that updates the contents of the policy database 903.

First, the policy database 903 will be described with reference to FIGS. 1 to 3 and FIG. FIG. 4 is a diagram illustrating the policy database of FIG.
The policy database 903 includes a VPN user ID 911 for identifying a user of the VPN service, basic optical path contract information 912 that is information of the basic optical path 6 that the user (each user site 4) uses fixedly, and a cut It includes the upper limit bandwidth of the through path 7 and cut-through path contract information 913 indicating the current usage band.

  The basic optical path contract information 912 includes the topology of the basic optical path 6 (which edge router 2 and which edge router 2 sets the basic optical path 6), and the bandwidth allocated in the topology (each section). Information. The cut-through path contract information 913 includes a contract upper-limit band 915 indicating the upper-limit band of the cut-through path 7 and a currently-used band 914 indicating the current use band of the cut-through path 7.

  For example, in FIG. 4, the user of VPN user ID # 1 is connected between the edge routers 2A and 2B (A-B), between the edge routers 2B and 2C (B-C), and between the edge routers 2C and 2D. It is shown that a contract for allocating a bandwidth of 1 Gbps as the basic optical path 6 is made for each of the intervals (CD).

  Further, it is indicated that the edge router 2 of the VPN user ID # 1 has a contract for using the cut-through path 7 up to 5 Gbps in addition to the basic optical path contract. Furthermore, it shows that a cut-through path 7 of 1 Gbps is established between the edge routers 2A and 2D at the present time. The VPN user ID 911, basic optical path contract information 912, and contract upper limit bandwidth 915 in the policy database 903 are input by the VPN operator via the input / output interface of the policy server 9 after the contract is established with the user. .

  Returning to the description of FIG. When the cut-through determination unit 901 in FIG. 3 receives the request for establishing the cut-through path 7 from the edge router 2, the edge router 2 establishes the cut-through path 7 with reference to the VPN user ID and the band included in the establishment request. Determine whether it is possible. Then, the determination result is returned (response) to the edge router 2.

  When the cut-through path information update unit 902 receives information indicating that the cut-through path 7 has been established from the edge router 2, the cut-through path information update unit 902 writes this information in the policy database 903. For example, from the edge router 2A connected to the user site 4 (site A) with the user ID # 1, the edge router 2A establishes a cut-through path 7 with the edge router 2D, and a bandwidth of 1 Gbps is set in this path. When the information indicating the setting is received, the information is written in the in-use band 914 of the policy database 903 (see FIG. 4).

  The policy database 903 is stored in the storage unit of the policy server 9, and the cut-through determination unit 901 and the cut-through path information update unit 902 are realized by arithmetic processing by the CPU of the policy server 9.

FIG. 5 is a block diagram showing a functional development of the configuration of the usage record server of FIG.
The function of the usage record server 10 of FIG. 1 will be described with reference to FIGS. The usage record server 10 is realized by a computer including a CPU, a storage unit, an input / output interface, and the like.

The usage record server 10 includes a usage record database 101 and a usage record writing unit 102 that writes various types of information to the usage record database 101.
FIG. 6 is a diagram illustrating the usage record database of FIG. As shown in FIG. 6, the usage record database 101 includes a VPN user ID 111 and a cut-through path usage record 112 describing the cut-through path 7 used by the user. This cut-through path usage record 112 includes the use start date / time (establishment time), use end date / time (release time) of the cut-through path 7, the section in which the cut-through path 7 is established, the optical path ID of the cut-through path 7, and the cut-through path 7. It shows information about the set bandwidth.

  For example, in the usage record database 101 of FIG. 6, the user with the VPN user ID # 1 is between the edge routers 2A and 2D from 10:00 on March 11, 2005 to 16:00 on March 11, 2005. This shows that the cut-through path 7 having the optical path ID XX is set with a bandwidth of 1 Gbps.

  The usage record database 101 is written by the usage record writing unit 102 according to the establishment and release information of the cut-through path 7 transmitted from the edge router 2 via the policy server 9.

  By referring to the information in the usage record database 101, the VPN operator can set the cut-through path 7 for the user ID # 1 and the bandwidth set for the path. Charges can be made accordingly. In addition, the user also makes a contract to set the basic optical path 6 in a section with a large amount of traffic on a daily basis, and to set the cut-through path 7 in a section where a band is to be secured only for a specific time. By connecting with a VPN provider, the usage fee for the IP-VPN service can be reduced.

FIG. 7 is a diagram illustrating a procedure in which the edge router according to the present embodiment establishes a cut-through path.
The procedure for the edge router 2 to establish the cut-through path 7 will be described using FIG. 7 with reference to FIGS. Here, a basic optical path 6 (fixed optical path) is set in advance between the edge routers 2A and 2B in FIG. 1, between the edge routers 2B and 2C, and between the edge routers 2C and 2D. A case where a cut-through path 7 between the routers 2A and 2D is added will be described as an example.

  First, the traffic measurement unit 202 of each edge router 2 measures the traffic volume between the user sites 4 (S1). Here, for example, when the traffic volume from the edge router 2A to the edge router 2D in a predetermined time exceeds a threshold value 205 set in advance in the edge router 2A, the optical path control processing unit 201 of the edge router 2A 9 sends a cut-through request message (cut-through path establishment request message) (S2). The cut-through path establishment request message includes, for example, the VPN user ID (# 1) of the user requesting the establishment of the cut-through path 7, the address (D) of the destination edge router 2 that establishes the cut-through path 7, Information on the bandwidth (1 Gbps) set for the cut-through path 7 is included. The VPN user ID may be received by the edge router 2 from the user site 4 or may be manually set in the edge router 2 by the VPN operator.

  The cut-through determination unit 901 of the policy server 9 that has received this message refers to the policy database 903 and determines whether or not the cut-through path 7 can be established (S3). Specifically, referring to the VPN user ID described in the cut-through path establishment request message, the contract information about the cut-through path 7 of the user (contract upper limit bandwidth 915 in FIG. 4) and the current use status of the through-path ( It is determined whether or not the value is equal to or less than the value of the contract upper limit band 915 when the new cut-through path 7 is established by comparing with the in-use band 914).

  For example, when there is a request for establishing a 1 Gbps cut-through path 7 between the edge router 2A and the edge router 2D in FIG. 1, the cut-through determination unit 901 refers to the policy database 903 (see FIG. 4) to The upper limit of the contract bandwidth that can be used for the through path 7 is 5 Gbps, but since only 1 Gbps is currently used, it is determined that a new cut-through path 7 can be established.

In this way, after determining whether the cut-through path 7 can be established, the policy server 9
The determination result is transmitted to the edge router 2 (2A) as a cut-through availability response message (S4). Then, the edge router 2 (2A) that has received this cut-through pass / fail response message, if this determination result is OK (cut-through path can be set), sends the cut-through path 7 (optical) to the destination edge router 2 (2D). Path) is established (S5). The cut-through path 7 is established by the optical path control processing unit 201 of the edge router 2 (2A) exchanging a band control signal via the GMPLS control plane 8 in accordance with the GMPLS standard protocol.

  In addition, in determining whether or not the cut-through path 7 of S3 can be established, if the cut-through determination unit 901 determines that the cut-through path 7 cannot be established (NG), that is, if a new cut-through path 7 is established, the contract upper limit bandwidth When it is determined that the value exceeds 915, the cut-through availability response message includes the determination result indicating that cut-through is not possible and is transmitted to the edge router 2 (2A). Then, the edge router 2 that has received this message does not establish the cut-through path 7.

  In S5, when the optical path control processing unit 201 of the edge router 2 (2A) establishes the cut-through path 7, a cut-through path establishment notification message for notifying that the cut-through path 7 has been successfully established is transmitted to the policy server 9. (S6).

  In this cut-through path establishment notification message, for example, the VPN user ID (# 1), the address (D) of the edge router 2 that is the destination of the cut-through path 7, and the bandwidth (1 Gbps) are uniquely identified. A possible optical path ID (XX) is included. Here, when GMPLS is applied to the establishment of the optical path, a combination of the destination address of the optical path and the Tunnel I ID of the VPN may be used as the optical path ID.

  The policy server 9 that has received the cut-through path establishment notification message registers that the cut-through path 7 has been established in the policy database 903 (see FIG. 4) (S7). Specifically, the cut-through path information update unit 902 in FIG. 3 increases the information regarding the used band 914 in the policy database 903 by the band of the newly established cut-through path 7.

  Next, the policy server 9 notifies the usage record server 10 that the use of the cut-through path 7 is newly started using a cut-through path usage start record request message (S8). For example, the cut-through path information update unit 902 of the policy server 9 sends a VPN user ID (# 1) for identifying the user who has established the cut-through path 7 to the usage recording server 10 and the edge router 2 that is the destination of the cut-through path 7 A cut-through path use start recording request message including the address (D), bandwidth (1 Gbps), optical path ID (XX), and the like is transmitted.

  The usage recording server 10 that has received this cut-through path usage start recording request message records the usage start of the cut-through path 7 in the usage recording database 101 (S9). For example, the usage record writing unit 102 (see FIG. 5) of the usage record server 10 stores the user ID of VPN user ID # 1 in the usage record database 101 at 1 Gbps in the interval between the edge routers 2A and 2D (AD). Record that cut-through path 7 was established on March 11, 2005 at 10:00 (see Figure 6). The establishment date and time of the cut-through path 7 at this time may be the date and time when the usage record server 10 receives the cut-through path utilization start record request message, or uses the time stamp included in the cut-through path utilization start record request message. Also good.

  Then, the usage record writing unit 102 transmits a cut-through path usage start record response message to the policy server 9 to notify that the usage start has been normally recorded (S10). Upon receiving this, the cut-through path information update unit 902 of the policy server 9 forwards the cut-through path establishment notification response message to the edge router 2 (2A) (Sll), and normally records the cut-through path 7 in the policy database 903. And the usage record database 101 is notified that the usage record has been made. In this way, the edge router 2 (2A) ends the establishment of the cut-through path 7.

FIG. 8 is a diagram illustrating a procedure for releasing the cut-through path by the edge router according to the present embodiment.
A procedure for the edge router 2 to release the cut-through path 7 will be described with reference to FIGS. Here, a case where the edge router 2A releases the cut-through path 7 established in FIG. 7 will be described as an example.

  First, the traffic measurement unit 202 of the edge router 2 (2A) measures the traffic amount between the user sites 4 (S101). Here, for example, when the amount of traffic from the edge router 2A to the edge router 2D falls below the threshold value 205 set in advance in the edge router 2A during a predetermined time, the optical path control processing unit 201 of the edge router 2A The cut-through path 7 is released using GMPLS signaling (S102). That is, the optical path control processing unit 201 returns the path to the basic optical path 6.

  Next, the optical path control processing unit 201 of the edge router 2A notifies the policy server 9 that the cut-through path 7 has been normally released by a cut-through path release notification message (S103). In the cut-through path release notification here, for example, the VPN user ID (# 1) of the released cut-through path 7, the address (D) of the edge router 2D of the released cut-through path 7, and the cut-through path 7 are set. This includes information on the bandwidth (1 Gbps) and the optical path ID (XX).

  When receiving the cut-through path release notification, the cut-through path information update unit 902 of the policy server 9 transmits a cut-through path use end record request message to the use record server 10 (S104). The cut-through path use end recording request message also includes the VPN user ID (# 1), the address (D) of the destination edge router 2 for establishing the cut-through path 7, and the bandwidth (1 Gbps) set for the cut-through path 7 It contains information about

  When the usage record server 10 receives the cut-through path usage end record request message, the usage record writing unit 102 records the usage end of the corresponding cut-through path 7 in the usage record database 101 (S105). For example, when the cut-through path 7 set between the edge routers 2A and 2D (AD) is released at 16:00 on March 11, 2005, the usage record writing unit 102 stores the usage record database 101 in the usage record database 101. Information “2005-03-11 16:00” is written in the column of the use end date and time (see FIG. 6). The use end date and time of the cut-through path 7 here may be the date and time when the use record server 10 receives the cut-through path use end record request message, or the time stamp included in the cut-through path use end record request message may be used. Good.

  Thereafter, the use record writing unit 102 notifies the policy server 9 that the cut-through path use end record has been normally recorded using a cut-through path use end record response message (S106). When the cut-through path information update unit 902 of the policy server 9 receives the cut-through path use end record response message, the cut-through path information update unit 902 deletes the registration (recording) of the cut-through path 7 of the corresponding user in the policy database 903 (S1007). Alternatively, when a plurality of cut-through paths 7 are set, a process of reducing the value of the in-use band of the policy database 903 by the band of the released cut-through path 7 may be performed.

  Thereafter, the cut-through path information update unit 902 notifies the edge router 2 (2A) that all of the cut-through path release processing has been normally completed with a cut-through path release response notification message (Sl08). In this way, the edge router 2 (2A) finishes releasing the cut-through path 7.

  By performing the processing as described above, the usage record server 10 can grasp the usage time (the time from the usage start date to the usage end date) and the usage band of the cut-through path 7 set by the edge router 2. In addition, since the edge router 2 cannot establish the cut-through path 7 when the policy server 9 does not permit the establishment of the cut-through path 7, the edge router 2 can prevent the user from using the cut-through path 7 having a bandwidth equal to or higher than the contracted bandwidth.

  Therefore, even if the VPN operator replaces the backbone network of the VPN service with a path-based optical network in order to increase the capacity and economy, the user does not need to perform detailed circuit design between bases. An easy-to-use VPN service similar to that of the base backbone network can be provided. In addition, it is possible to perform pay-as-you-go billing according to optical path usage (time / bandwidth), which could not be provided by a path-based wide area network, and the user contracts the line according to the maximum bandwidth to be used. There is no need. Therefore, the user can use the VPN service economically. Furthermore, since it is not necessary for the VPN operator to set a path in accordance with the peak bandwidth between the user bases, it is possible to improve the utilization efficiency of the resources of the optical network.

  The edge router 2 according to the present embodiment can be realized by a VPN program for executing the processing as described above, and can be provided by storing the program in a computer-readable storage medium. . It is also possible to provide the program through a network.

  In the above-described embodiment, the policy server 9 and the usage record server 10 have been described as separate servers. However, these may be realized by a single server. That is, the policy server 9 may store the policy database 903 and the usage record database 102. Other modifications can be made without departing from the spirit of the present invention.

It is a figure which shows the network structure of this Embodiment. It is the block diagram which expanded and demonstrated the function of the edge router of this Embodiment. FIG. 2 is a block diagram showing a functional development of the configuration of the policy server of FIG. 1. It is the figure which illustrated the policy database of FIG. It is the block diagram which expanded and showed the function of the structure of the usage record server of FIG. It is the figure which illustrated the utilization record database of FIG. It is the figure which showed the procedure in which the edge router of this Embodiment establishes a cut-through path. It is the figure which showed the procedure in which the edge router of this Embodiment releases a cut-through path.

Explanation of symbols

1 Optical network 2 (2A, B, C, D) Edge router (edge node)
4 User site (user network)
6 Basic optical path (fixed optical path)
7 Cut-through path (additional optical path)
9 Policy Server 10 Usage Record Server 101 Usage Record Database 205 Threshold 903 Policy Database

Claims (6)

A VPN service providing method for connecting each user base to a VPN (Virtual Private Network) via an optical network,
An edge node of the optical network connected to the user network that is the base,
Establishing a fixed optical path with other edge nodes;
Measuring the amount of traffic with the other edge nodes;
When the measured traffic volume exceeds a predetermined threshold value stored in the storage unit of the edge node, establishing an additional optical path for the edge node that is a destination of traffic exceeding the predetermined threshold value; ,
Transmitting an additional optical path establishment notification including a user ID of the VPN service allocated to the user network, an optical path ID of the established additional optical path, and bandwidth information of the additional optical path;
Run
For each user ID, the VPN service usage record server comprising a usage record database indicating the usage record of the additional optical path,
Receiving the additional optical path establishment notification from the edge node;
Recording the received additional optical path establishment notification in the usage record database;
A VPN service providing method comprising: The VPN service providing method according to claim 1,
The edge node is
Releasing the established additional optical path when the measured traffic volume is less than or equal to the predetermined threshold;
Transmitting an additional optical path release notification including the user ID allocated to the user network and the optical path ID of the released additional optical path;
Run further,
The usage record server is
Receiving the additional optical path release notification from the edge node;
Based on the received additional optical path establishment notification and the additional optical path release notification, the bandwidth information of the established additional optical path and the establishment time and release time of the additional optical path are written in the usage record database. Steps,
A VPN service providing method, further comprising: An optical path establishment method in the VPN service providing method according to claim 1 or 2,
Before the edge node establishes the additional optical path, the edge node
For each user ID of the VPN service, an additional optical path including at least the user ID and the bandwidth of the additional optical path in a policy server including a policy database indicating an upper limit value of a bandwidth that can be set for the additional optical path. Further executing the step of sending an establishment request;
The policy server is
When it is determined that the bandwidth of the additional optical path that is the target of the establishment request is equal to or less than the upper limit value with reference to the policy database and the transmitted additional optical path establishment request, the edge node Sending a response to allow establishment of an additional optical path, and
The edge node is
An optical path establishment method, comprising: establishing an additional optical path when receiving a response to allow establishment of the additional optical path. The policy server is
With reference to the policy database and the transmitted additional optical path establishment request, when it is determined that the bandwidth of the additional optical path that is the target of the establishment request exceeds the upper limit value, the addition to the edge node Perform the step of sending a response that the optical path cannot be established;
The edge node is
4. The optical path establishment method according to claim 3, wherein when the response indicating that the additional optical path cannot be established is received, the establishment of the additional optical path is not executed.   5. The optical path establishment method according to claim 3, wherein the edge node establishes and releases an optical path using a GMPLS (Generalized Multi-Protocol Label Switching) protocol.   6. The optical path establishment method according to claim 3, wherein the edge node is a router using an IP (Internet Protocol) protocol.

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