JP2009232177A - User management system and method for reserving network path - Google Patents

Abstract

The present invention accepts a path reservation from a user who requests a network path with a quality condition, and reserves, sets and recalculates an optimal path in consideration of network resources.
A network management system obtains basic resource information including a reserved bandwidth and a line use start / end time from a user who uses the network, and acquires network resource information from the network management system. A network database with time axis information for storing network resource information expanded in the time axis direction, a route calculation engine unit for calculating an optimum route that matches the reservation basic information by referring to the database, and the optimum route A network topology configured to reflect the optimum route and the basic reservation information in the database, and to the network management system based on the provisional information based on the optimum route and the basic reservation information. And a provisioning unit for implementing the grayed.
[Selection] Figure 2

Description

  The present invention relates to a user management system and method for reserving a network path. More specifically, the present invention relates to a user management system and method for accepting a path reservation from a user who requests a network path with quality conditions, and reserving / setting / recalculating an optimal path in consideration of network resources.

  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 setting an LSP (Label Switched Path) in an MPLS (Multi Protocol Label Switching) network, the node that is to set the LSP refers to the link information database and calculates the 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.

  In addition, in order to respond to requests for various network services, there is a case where it is desired to perform line setting 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. At this time, whether or not the requested bandwidth can be secured at each node on the route is determined. This is not guaranteed, and therefore the line setting may fail, affecting service provision.

  For this reason, as a method for reserving a line with a desired bandwidth and setting a line reserved at a desired time, the node has time-series data and the required bandwidth and start / end time are exchanged in advance. Provided a method for bandwidth reservation autonomously distributed.

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.

  However, in the method of performing bandwidth reservation in an autonomous distributed manner, each node (router) has too much information, and the load on the node is increased. Further, since it is necessary to exchange information between nodes, this information is limited to the requested bandwidth and start / end time, and the user can only request the desired bandwidth and start / end time. Furthermore, since bandwidth reservation is performed in an autonomous and distributed manner, there is no guarantee that the reserved network path is a path that can efficiently use network resources. In addition, when a failure occurs on a reserved network path, or when a new path is added, no response is made to changes in network resources.

  Therefore, the present invention provides a user management system and method capable of accepting a path reservation from a user who desires a network path with quality conditions and reserving / setting / recalculating an optimum path in consideration of network resources. The purpose is to provide.

  According to the present invention, a network capable of route provisioning, a network management system for obtaining resource information from the network and provisioning a route for the network, and a communication system including a user management system for the network, A user interface unit that receives basic reservation information including a reserved bandwidth and a line use start / end time from a user who uses the network, and network resource information obtained from the network management system and extended in the time axis direction A network database with time axis information for storing information, a route calculation engine unit for calculating an optimum route that matches the reservation basic information by referring to the database, the optimum route, and the reservation A scheduling unit that reflects the information in the database, to the network management system, a user management system and a provisioning unit for implementing the provision on the basis of the optimal path and the reservation basic information is provided.

  The network further includes quality information, and the basic reservation information includes a line quality request, and the route calculation engine unit preferably calculates an optimum route that satisfies the line quality request.

  Further, the basic reservation information further includes a reserved route pattern, the reserved route pattern is information on a start point / end point node of a reserved route and a redundant pattern of a route between the nodes, and the route calculation engine unit includes: It is also preferable to calculate an optimum route that also satisfies the condition of the redundancy pattern.

  Moreover, it is preferable that the scheduling unit further has a function of causing the route calculation engine unit to recalculate the optimum route.

  The user interface unit preferably further has a function of accepting recalculation of an optimum route from an operator of the network and causing the scheduling unit to recalculate the optimum route.

  The route calculation engine unit extracts links that satisfy the conditions of the reservation basic information, configures a temporary topology from the links, and selects a temporary topology that satisfies the conditions of the reservation basic information from the configured temporary topology. From the selected temporary topologies, a temporary topology that satisfies the four conditions of the minimum link cost, the minimum number of hops, the most distributed link load, and the maximum link utilization rate is calculated as the optimum route. It is also preferable.

  According to the present invention, a network in which a route can be provisioned, a network management system that acquires resource information from the network and provisions a route to the network, and a user in a communication system including the user management system of the network In the management system, receiving basic reservation information including a reserved bandwidth and a line use start / end time from a user using the network, acquiring network resource information from the network management system, and extending in a time axis direction Creating a network database with time axis information for storing network resource information; calculating an optimum route that matches the reservation basic information by referring to the database; and There is provided a network route reservation method including the steps of reflecting an appropriate route and the basic reservation information in the database, and performing provisioning for the network management system based on the optimal route and the basic reservation information. The

  Since the user management system performs path reservation intensively, there is no need to exchange information between nodes of the network, and the load on the nodes is reduced. Furthermore, the user can make a path reservation for the user management system, and can also reserve a path with quality conditions such as priority and path type.

  In addition, when the user management system makes an optimal path reservation in consideration of resources, the use efficiency of network resources is improved. Furthermore, service down at the time of failure is reduced by recalculating the optimum path when a failure occurs. Also, resources can be effectively used by recalculating the optimum path when adding a new node.

  FIG. 1 shows a schematic configuration of a system according to the present invention. The system according to the present invention includes a user management system 1, a network management system 2, and a network 3 having quality information capable of path provisioning. In the present embodiment, an MPLS / GMPLS network is used as the network.

  The user management system 1 accepts a path reservation from a user who requests a network path with quality conditions, reserves an optimum MPLS / GMPLS path in consideration of network resources, and notifies the user of the result of reservation availability. The setting of the MPLS / GMPLS path is set by making a provisioning request in accordance with the reservation schedule to the network management system 2. The reservation by the user management system 1 is performed by constructing / updating the network resource database with time axis information, and the optimum route according to the request condition is calculated. Further, the calculated optimum route is recalculated as needed in response to a failure.

  The network management system 2 (NMS) receives an MPLS / GMPLS path setting request from the user management system 1 and performs MPLS / GMPLS path provisioning based on MPLS / GMPLS router control for the MPLS / GMPLS network 3. By this provisioning, a path from the CE router to the CE router in the MPLS / GMPLS network 3 is set. In addition, network resources are periodically acquired from the MPLS / GMPLS network 3, and network resource information is provided to the user management system 1.

  FIG. 2 shows a block diagram of a user management system 1 according to the present invention. As shown in FIG. 2, the user management system 1 includes a user interface unit 11, a scheduling unit 12, a provisioning unit 13, a route calculation engine 14, and a network database 15 with time axis information.

  The user management system 1 operates in cooperation with the NMS 2 and the MPLS / GMPLS network 3 and performs database creation, synchronization, user reservation reception, provisioning, failure handling, etc., and an MPLS / GMPLS network topology corresponding to the received reservation. Simulation and optimal route recalculation. Details of each component will be described below.

  The user interface unit 11 is a part that communicates with the user and the operator. For example, the user interface unit 11 receives a request from the user and the operator through the Web and displays the result. The user interface unit 11 has an authentication function, and authenticates the general user and the operator separately. For general users, for example, a new reservation input, reservation status reference, reservation deletion function, and the like are provided. For the operator, for example, it has a reservation status reference, a link usage status reference, a failure link recovery date input / correction, a new link addition, an optimum route recalculation function, and the like.

  The scheduling unit 12 receives basic reservation information (requested bandwidth, start / end time, line quality (Class of Service (CoS)), etc.) from the user from the user interface unit 11, and an optimum route calculated by the route calculation engine 14. From the virtual MPLS / GMPLS network topology composed of When the reservation is possible, the user interface unit 11 is notified that the reservation is possible. The optimum route and basic reservation information are reflected in the network database 15 with time axis information.

  In addition, when route information is changed due to a failure, construction work, or the like, recalculation / rescheduling of the optimum route is performed sequentially. Furthermore, recalculation and rescheduling are performed to reallocate resources when resources are congested.

  The provisioning unit 13 performs MPLS / GMPLS path provisioning based on the virtual MPLS / GMPLS network topology. Provisioning is performed by the NMS 2 via the provisioning interface, the path is set at the use start time, and the path is released at the use end time.

  The route calculation engine 14 calculates an optimum route from resource utilization efficiency and the like. The definition of the optimum route and the optimum route calculation algorithm are described below.

  The network database 15 with time axis information is a database expanded in the time axis direction, collects network resource information by synchronizing with the database of the NMS 2 via the database acquisition interface, and stores it in the database 15. Examples of network resources include the section, bandwidth, QoS, and parameters of each link. Further, the node address, the maximum link bandwidth, the node ID of the endpoint, the TE link address, the maximum available bandwidth for each priority, LSP encoding, SW capability, and SRLG are stored as link parameters. Note that LSP encoding and SW capability are stored only when the network is GMPLS.

  There is also a database of user information and reserved MPLS / GMPLS network topology, which is not specified in FIG. It is also possible to construct the database on the network database 15 with time axis information. In the user information database, for example, a user ID, a user alias (alias), and an account type (user / operator) are stored. In the case of a user account, the default D-plane address (0 system and 1 system), a default M-plane address of the user apparatus, and a connection destination list (D-plane destination) that can be selected at the time of reservation are held. The network topology database includes, for example, user ID, reserved bandwidth, priority, start router address (start node information), end router address (end node information), maximum allowable link cost, maximum allowable hop count, The path information, the D-plane addresses of the 0-system and 1-system user devices, the M-plane address of the user devices, and the path type are stored. Here, the path type is a reserved path pattern in consideration of redundancy, and in the present embodiment, there are the following four patterns.

FIG. 3 shows a pattern of CE router redundancy, 1 + 1, and independent 2 routes of a reserved path according to the present invention. In this pattern, CE (Customer Edge) routers at the start point and end point are made redundant, and two MPLS paths for each of the active system and the standby system are set between the CE routers. Furthermore, routes 1 to 4 are
• Do not pass the same node and the same TE link in route 1 and route 2.
-Do not pass the same node and the same TE link in route 3 and route 4.
• Do not pass the same node and the same TE link in route 1 and route 3.
-Route 2 and route 4 must not pass through the same node and the same TE link.
The condition is imposed.

FIG. 4 shows a CE path redundant, independent two-path pattern of reserved paths according to the present invention. In this pattern, the start and end CE routers are made redundant, and one MPLS path is set between the CE routers. Furthermore, routes 1 and 2 are
• Do not pass the same node and the same TE link in route 1 and route 2.
The condition is imposed.

FIG. 5 shows a pattern of reserved path CE router non-redundant, 1 + 1, and independent two paths according to the present invention. In this pattern, the start and end CE routers are not made redundant, and two MPLS paths are set between the CE routers. Furthermore, routes 1 and 2 are
• Do not pass the same node and the same TE link in route 1 and route 2.
The condition is imposed.

  FIG. 6 shows a CE path non-redundant, single path pattern of a reserved path according to the present invention. In this pattern, the start and end CE routers are not made redundant, and one MPLS path is set between the CE routers.

  Hereinafter, an algorithm for calculating the optimum route executed by the route calculation engine 14 will be described.

First, the optimum route is defined as follows. The prerequisites for being the optimal route are:
(H1) Available in the reserved time zone (H2) Link parameters are compatible (in the case of GMPLS)
(H3) Link disjoint (redundant paths do not pass through the same link) *
(H4) Node disjoint (redundant path does not pass through the same node) *
(H5) SRLG (Do not use optical fibers with the same redundant path) *
It is. However, the items marked with * (H3) to (H5) can be provided with options if they cannot be realized in the topology. For example, no checking is performed in the algorithm for obtaining the optimum route, and up to n same nodes and / or links are allowed on the redundant route.

Of the routes that meet the above requirements, the best route is
(S1) The link cost is minimum.
(S2) The hop count (routed node count) is the smallest.
(S3) The link load is distributed. That is, the distribution of all TE link loads on the path is minimal.
(S4) The link availability is maximized. That is, the average of all TE link loads on the path is the smallest.
Is defined as satisfying However, it is possible to prioritize a plurality of items by weighting the above four items. This weighting is realized by the user interface unit 11 providing a slider or a pull-down menu.

Next, the optimal route calculation algorithm of this embodiment will be described with reference to the drawings.
(A1) First, paying attention to each TE link as shown in FIG. 7, it is determined whether or not each TE link satisfies the above requirements (H1) and (H2). For the determination of (H1), a two-dimensional plane (time axis / band axis) is cut out with a desired priority as shown in FIG. 8, and the requested band is changed to all available bands within the required time as shown in FIG. Check that it fits. In the case of GMPLS, the GMPLS parameter is checked to determine (H2).
(A2) As shown in FIG. 10, a temporary topology is constructed by extracting only the links that satisfy the above-mentioned necessary conditions.
(A3) Of the constructed temporary topologies, those satisfying the necessary conditions (H3) to (H5) are selected, and those satisfying the conditions (S1) to (S4) of the optimum route are calculated as optimum routes. The In the case where weighting relating to these conditions has been performed, it is assumed that the condition with the highest weighting has a high priority, and the one that satisfies at least the condition is calculated.

  Next, recalculation of the optimum route will be described. Since the link in the calculated optimum route cannot be used due to the occurrence of a link failure or the establishment of a new link, an optimum route recalculation function is required.

  The timing for recalculating the optimum route is when a link failure occurs, when a link is newly established, or when it is manually performed by an operator at an arbitrary timing. When a failure occurs, it is performed when a failure notification is received from the NMS, or when the operator inputs the failure recovery date and time. Also, when a link is newly established, it is performed when the operator inputs the link provision start date and time.

  In this recalculation, when a failure occurs, the recalculation is performed sequentially for the optimum route including the failed link, and the operator is notified. If the influence of the failure link is so great that all the optimum routes cannot be reserved, the calculation is recalculated by changing the reserved path pattern. When a link is newly established or manually performed by the operator, the calculation time required for recalculation can be limited by inputting the calculation time by the operator. It is also possible to calculate with a plurality of reserved path patterns, display the calculated optimum route on the screen, and allow the operator to compare and review.

  Next, reservations that are recalculated will be described. The recalculation covers all reservations that overlap with a specific time zone. The specific time zone is a time zone in which a link cannot be used due to a failure when a failure occurs, and after a time when a new link can be used when adding a new link. However, it is also possible to set a recalculation prohibition flag in the reservation information so that recalculation is not performed when a link is newly established or when it is manually performed by an operator.

In the event of a failure, the reservation to be recalculated is specifically as follows.
• Paths that are currently being set (providing service) and that include a failed link are subject to recalculation.
• Paths that are currently set and do not include a faulty link are not subject to recalculation.
• Paths that are currently not set and include a failed link (if not restored by the time of setting) are subject to recalculation.

When a new link is added or when it is manually performed by the operator, the reservation to be recalculated is specifically as follows.
・ Basically, all reservations in the applicable time zone are eligible.
・ Reservations for which a recalculation prohibition flag is set are excluded.

  When recalculation is performed, if the recalculation is performed in the order in which reservations are received, an optimal result cannot always be calculated. For this reason, recalculation is performed in the order of long reservation time, high hop count, and late reservation start time. It is also possible to perform recalculation by appropriately combining these orders.

  A specific usage example of the user management system 1 will be described. When the system is activated, the failure management between the user management system 1 and the NMS 2 is performed, and then the NMS 2 database is collated, synchronized with the network database 15 with time axis information, and a path setting request from the user is awaited. During idle time waiting for a path setting request from the user, the database of the NMS 2 is periodically checked and synchronized, and the failure monitoring between the user management system 1 and the NMS 2 is performed.

An example of a flow in which a user makes a path reservation to the user management system 1 and a path is set is shown.
1. A user accesses the user management system 1 with a Web browser or the like.
2. The user inputs path setting information necessary for reservation to the user management system 1 via the Web browser.
3. The user management system 1 collates with the network database 15 with time axis information based on the input information, and the route calculation engine 14 selects the optimum route.
4). The user management system 1 returns a result of availability to the user.
5. When there is no problem in the route indicated by the user management system 1, the user makes a reservation request.
6). The user management system 1 performs this reservation and the reservation is confirmed.
7). The user management system 1 updates information in the network database 15 with time axis information.
8). The user management system 1 puts into the LSP setting queue.
9. When the reservation time arrives,
10. The user management system 1 accesses the NMS 2 using the provisioning interface.
11. The user management system 1 inputs a provisioning command to the NMS 2.

  Moreover, all the embodiment described above shows the present invention exemplarily, and does not limit the present invention, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

1 shows an outline of the configuration of a system according to the present invention. 1 shows a block diagram of a user management system according to the present invention. FIG. 4 shows CE router redundancy, 1 + 1, and independent 2 path patterns of reserved paths according to the present invention. FIG. 4 shows a CE router redundant, independent two-route pattern of a reserved path according to the present invention. Fig. 4 shows CE router non-redundant, 1 + 1, independent 2 path patterns of reserved paths according to the present invention. 4 shows a CE router non-redundant, single path pattern of a reserved path according to the present invention. The attention of each TE link is shown in the algorithm for calculating the optimum route according to the present invention. It shows that an optimal route calculation algorithm according to the present invention cuts out in a two-dimensional plane with a desired priority. The confirmation that the requested bandwidth falls within all the available bandwidths within the requested time in the algorithm for calculating the optimum route according to the present invention is shown. The construction of the temporary topology is shown by the algorithm for calculating the optimum route according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 User management system 2 Network management system 3 MPLS / GMPLS network 11 User interface part 12 Scheduling part 13 Provisioning part 14 Path calculation engine 15 Network database with time-axis information

Claims (7)

In a communication system including a network capable of provisioning a route, a network management system for obtaining resource information from the network and provisioning a route for the network, and a user management system for the network,
A user interface unit that receives basic reservation information including a reserved bandwidth and a line use start / end time from a user who uses the network;
A network database with time axis information for acquiring network resource information from the network management system and storing network resource information expanded in the time axis direction;
By referring to the database, a route calculation engine unit that calculates an optimum route that matches the reservation basic information;
A scheduling unit for reflecting the optimum route and the basic reservation information in the database;
A provisioning unit that performs provisioning for the network management system based on the optimum route and the basic reservation information;
A user management system comprising:   2. The network according to claim 1, wherein the network further includes quality information, the basic reservation information includes a line quality request, and the route calculation engine unit calculates an optimum route that also satisfies the line quality request. The user management system described. The reserved basic information further includes a reserved route pattern, and the reserved route pattern is information on a start point / end point node of a reserved route and a redundancy pattern of a route between the nodes,
The user management system according to claim 2, wherein the route calculation engine unit calculates an optimum route that also satisfies the condition of the redundancy pattern.   4. The user management system according to claim 1, wherein the scheduling unit further has a function of causing the route calculation engine unit to recalculate the optimum route. 5.   The user according to claim 4, wherein the user interface unit further has a function of accepting recalculation of an optimum route from an operator of the network and causing the scheduling unit to recalculate the optimum route. Management system.   The route calculation engine unit extracts links that satisfy the conditions of the basic reservation information, configures a temporary topology from the links, selects a temporary topology that satisfies the conditions of the basic reservation information from the configured temporary topology, and selects The temporary topology that satisfies any of the four conditions of the minimum link cost, the minimum number of hops, the most distributed link load, and the maximum link availability is selected as the optimal route. 6. The user management system according to claim 1, wherein the user management system is calculated. In a network capable of route provisioning, a network management system for obtaining resource information from the network and provisioning a route to the network, and a user management system in a communication system including a user management system of the network,
Receiving reservation basic information including a reserved bandwidth and a line use start / end time from a user using the network; and
Obtaining network resource information from the network management system and creating a network database with time axis information for storing network resource information expanded in the time axis direction;
Calculating an optimal route that matches the reservation basic information by referring to the database;
Reflecting the optimal route and the basic reservation information in the database;
Implementing provisioning to the network management system based on the optimum route and the basic reservation information;
A network route reservation method comprising:

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