JP3918993B2 - Network management apparatus and address assignment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a network management apparatus and an address assignment method, and more particularly, to a network management apparatus and an address assignment method applied to the operation of a radio access network composed of radio base stations to which information processing apparatuses are connected via radio. .
[0002]
[Prior art]
A radio access network composed of radio base stations connected to an information processing apparatus via radio is used. Each of these radio base stations is assigned an IP address that is uniquely determined within the radio access network. The radio base station uses the IP address to identify the destination radio base station. The assignment of the IP address to the radio base station is performed based on the experience of the manager of the radio access network, and the manager actually goes to the radio base station and sets the IP address.
[0003]
Such a radio access network has a complicated network configuration when there are a large number of radio base stations, and an appropriate IP address cannot be assigned only by the experience of the network administrator. A method for easily assigning an IP address to a radio base station is desired.
[0004]
In order to normally operate a radio access network, an NMS (Network Management System) that manages the configuration, failure, and performance of radio base stations is used. This NMS monitors and controls the radio access network using the SNMP protocol. At this time, when an alarm / event requested by the NMS occurs, the radio base station autonomously notifies the NMS accordingly.
[0005]
The NMS can further add a function of dynamically assigning an IP address to a radio base station, such as a DHCP server function. At this time, in the radio access network, communication is performed so that each radio base station requests an IP address from the NMS, and the NMS checks the IP address assigned to each radio base station. When there are many radio base stations, the radio access network may increase traffic and adversely affect other communications. In addition, since a specific IP address cannot be assigned to a specific radio base station, the degree of freedom of the network administrator may be hindered and the IP address may be exhausted. There is a demand for a network management system and an address assignment method that prevent exhaustion of IP addresses used in a radio access network.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a network management apparatus and an address allocation method that prevent exhaustion of IP addresses used in a radio access network.
Another object of the present invention is to provide a network management apparatus and an address assignment method that can easily prevent exhaustion of IP addresses used in a radio access network.
[0007]
[Means for Solving the Problems]
Hereinafter, means for solving the problem will be described using the numbers and symbols used in [Embodiments of the Invention] with parentheses (). These numbers and symbols are added to clarify the correspondence between the description of [Claims] and the description of [Mode for carrying out the invention], and are described in [Claims]. It should not be used to interpret the technical scope of the claimed invention.
[0008]
The network management device (2) according to the present invention divides a plurality of radio base stations (3-1 to 3-10) forming a communication network (1) into a plurality of sub-networks (6-1 to 6-3) which are prime to each other. A subnet creation unit (11) that performs the above and an address assignment unit (12) that assigns addresses to the radio base stations that belong to the plurality of subnets (6-1 to 6-3) among the plurality of radio base stations (3-1 to 3-10). ). The plurality of radio base stations (3-1 to 3-10) include one uppermost radio base station (3-1) directly connected to the network management device (2), and the highest radio base station (3- Unlike 1), a plurality of terminal radio base stations (3-6, 3-8, 3-10) directly connected to only one radio base station among the plurality of radio base stations (3-1 to 3-10). ). Each of the multiple subnets (6-1 to 6-3) includes only one terminal radio base station (3-6, 3-8, 3-10). The plurality of radio base stations belonging to one of the plurality of subnets (6-1 to 6-3) are the number of radio base stations on the path connected to the highest radio base station (6-1), that is, the depth Are preferably different from each other. Such subnetting reduces the number of subnets and prevents depletion of addresses assigned to a plurality of radio base stations (3-1 to 3-10).
[0009]
The address includes a network part and a host part. The addresses assigned to the radio base stations belonging to one subnet among the plurality of subnets (6-1 to 6-3) have the same network part, and the host part belongs to one subnet and the radio base station and the network address. It is formed from the minimum number of digits that can be sufficiently distinguished from the broadcasting address. The address can be divided into a network part and a host part using a netmask. The number of digits of the network part and the host part is set for each sub-address and can be different. Such assignment prevents exhaustion of addresses assigned to the plurality of radio base stations (3-1 to 3-10).
[0010]
The number of radio base stations belonging to the subnet including the highest radio base station (3-1) among the plurality of subnets (6-1 to 6-3) is among the plurality of subnets (6-1 to 6-3). The maximum is preferred.
[0011]
The network management device (2) according to the present invention includes a correspondence table creation unit (13) that creates a correspondence table (21) that associates a plurality of radio base stations (3-1 to 3-10) and addresses, and a correspondence table ( 21) further includes a correspondence table transmission unit (14) that transmits a version indicating the newness of the correspondence table (21) to the highest radio base station (3-1). The highest radio base station (3-1) downloads the correspondence table (21) together with the version from the network management device (2). The multiple radio base stations (3-1 to 3-10) are directly connected to the first radio base station that records the first correspondence table and the second correspondence table and records the second correspondence table. A second radio base station. The first radio base station preferably downloads the second correspondence table together with the version from the second radio base station when the first correspondence table is newer than the second correspondence table.
[0012]
The address allocation method according to the present invention includes a step of dividing a plurality of radio base stations (3-1 to 3-10) forming a communication network (1) into a plurality of prime subnets (6-1 to 6-3) ( S3) and a step (S3) of allocating addresses to the radio base stations belonging to the plurality of subnets (6-1 to 6-3) among the plurality of radio base stations (3-1 to 3-10). . The plurality of radio base stations (3-1 to 3-10) include one uppermost radio base station (3-1) directly connected to the network management device (2), and the highest radio base station (3- Unlike 1), a plurality of terminal radio base stations (3-6, 3-8, 3-10) directly connected to only one radio base station among the plurality of radio base stations (3-1 to 3-10). ). Each of the multiple subnets (6-1 to 6-3) includes only one terminal radio base station (3-6, 3-8, 3-10). The plurality of radio base stations belonging to one of the plurality of subnets (6-1 to 6-3) are the number of radio base stations on the path connected to the highest radio base station (6-1), that is, the depth Are preferably different from each other. Such subnetting reduces the number of subnets and prevents depletion of addresses assigned to a plurality of radio base stations (3-1 to 3-10).
[0013]
The address includes a network portion and a host portion. The addresses assigned to the radio base stations belonging to one of the plurality of subnets (6-1 to 6-3) are the same in the network portion, and the host portion. Are formed from the minimum number of digits that can sufficiently identify the radio base station belonging to one subnet, the network address, and the broadcasting address. The address can be divided into a network part and a host part using a netmask. The number of digits of the network part and the host part is set for each sub-address and can be different. Such assignment prevents exhaustion of addresses assigned to the plurality of radio base stations (3-1 to 3-10).
[0014]
The number of radio base stations belonging to the subnet including the highest radio base station (3-1) among the plurality of subnets (6-1 to 6-3) is among the plurality of subnets (6-1 to 6-3). The maximum is preferred.
[0015]
The address allocation method according to the present invention includes a step of creating a correspondence table (21) for associating a plurality of radio base stations (3-1 to 3-10) and addresses, and the correspondence table (21) as a correspondence table (21). And a step of transmitting to the highest radio base station (3-1) together with a version indicating the newness. The highest radio base station (3-1) downloads the correspondence table (21) together with the version from the network management device (2), and the plurality of radio base stations (3-1 to 3-10) obtain the first correspondence table. A first radio base station that is recording, and a second radio base station that is directly connected to the first radio base station and that records a second correspondence table. Is preferably newer than the second correspondence table, the second correspondence table is preferably downloaded together with the version from the second radio base station.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a radio access network system to which a network management apparatus according to the present invention is applied will be described with reference to the drawings. The radio access network system 10 includes a radio access network 1 and a network management device 2 as shown in FIG. The radio access network 1 is formed from a plurality of radio base stations 3-1 to 3-10. The radio access network 1 is a point-to-point system, and the radio base stations 3-1 to 3-10 are bidirectionally connected to information processing apparatuses exemplified by workstations via radio waves. Has been.
[0017]
The radio base stations 3-1 to 3-10 are bidirectionally connected to each other directly or indirectly via a transmission path. That is, the radio base station 3-1 is connected to the radio base station 3-2. The radio base station 3-2 is connected to the radio base station 3-3 and is connected to the radio base station 3-9. The radio base station 3-3 is connected to the radio base station 3-4 and is connected to the radio base station 3-7. The radio base station 3-4 is connected to the radio base station 3-5. The radio base station 3-5 is connected to the radio base station 3-6. The radio base station 3-7 is connected to the radio base station 3-8. The radio base station 3-9 is connected to the radio base station 3-10.
[0018]
The network management device 2 is an information processing device, and is a so-called NMS (Network Management System) that manages the radio base stations 3-1 to 3-10 and operates the radio access network 1. The network management device 2 is bidirectionally connected to the radio base station 3-1 via a local area network (LAN) 4.
[0019]
The radio access network 1 is divided into a plurality of subnets 6-1 to 6-3 by the network management device 2. The subnet 6-1 is formed from radio base stations 3-1 to 3-6. The subnet 6-2 is formed of radio base stations 3-7 and 6-8. The subnet 6-3 is formed of radio base stations 3-9 and 6-10.
[0020]
That is, the radio access network 1 forms a graph in which the radio base stations 3-1 to 3-10 are apexes and the transmission path is an edge, and any two of the radio base stations 3-1 to 3-10 are formed. The only path connecting the two radio base stations 3-i (i = 1, 2, 3,..., 10) and 3-i ′ (i ′ = 1, 2, 3,..., 10; i ′ ≠ i) The so-called tree structure is determined.
[0021]
Here, in the present specification, the number of other radio base stations 3-i ′ directly connected to the radio base station 3-i is defined as an order, and two different radio base stations 3-i, 3-i The number of transmission paths in the path connecting i ′ is defined as the path length. Furthermore, the radio base station 3-1 directly connected to the network management device 2 is defined as the highest radio base station, and the radio base stations 3-6, 3, 3 having an order of 1 except for the highest radio base station. −8 and 3-10 are defined as terminal radio base stations, and the length of the path connecting the highest radio base station and the radio base station is defined as the depth of the radio base station.
[0022]
That is, each of the subnets 6-1 to 6-3 forms a road structure in which radio base stations having different depths are connected in a straight line, and includes only one terminal radio base station. Further, the subnet 6-1 including the highest radio base station includes the radio base station 3-6 having the largest depth.
[0023]
FIG. 2 shows the network management device 2 in detail. The network management device 2 includes a subnet creation unit 11, an IP address assignment unit 12, a correspondence table creation unit 13, a correspondence table transmission unit 14, and a setting completion notification reception unit 15 that are computer programs.
[0024]
The subnet creation unit 11 divides the radio base stations 3-1 to 3-10 into a plurality of subnets 6-1 to 6-3 when the structure of the radio access network 1 is changed. That is, the subnet creation unit 11 first searches for a terminal radio base station having the greatest depth using a well-known vertical search algorithm, and connects the terminal radio base station with the highest radio base station. Subnet the set of stations. Next, the subnet creation unit 11 searches for a terminal wireless base station having the greatest depth among the wireless base stations that are not subnetted, and uses a route that connects the terminal wireless base station and the highest wireless base station. The step of subnetting a set of non-subnetted radio base stations among certain radio base stations is repeated. Such subnetting further reduces the number of subnets.
[0025]
The IP address assignment unit 12 assigns an IP address to the radio base stations 3-1 to 3-10 subnetted by the subnet creation unit 11. The IP address includes a network portion that identifies the subnet 6-j (j = 1, 2, 3) and a host portion that identifies the radio base station 3-i. The host part is formed with the smallest digit that can represent a numerical value obtained by adding 2 to the number of radio base stations 3-i belonging to the subnet 6-j, and a radio base station with a small depth has a large depth. The numerical value of the host part is smaller than that of the radio base station. An IP address having a host part value of 0 is a network address and indicates a subnet 6-i. The IP address which is the maximum value that can be expressed by the host part is a broadcast address, and indicates all radio base stations belonging to the subnet 6-i. Network addresses and broadcast addresses are created for each subnet. As a result, reduction of the number of subnets prevents exhaustion of addresses assigned to the plurality of radio base stations (3-1 to 3-10).
[0026]
The IP address assigning unit 12 further derives a netmask for each IP address, which is a numerical value for dividing the IP address into a network part and a host part. That is, the logical product of the IP address and the subnet mask is the network part, and the logical product of the negation of the subnet mask and the IP address is the host part. Such a netmask is the same for the radio base station 3-i belonging to one subnet 6-j and can be different for two different subnets.
[0027]
The correspondence table creation unit 13 creates a correspondence table that associates each radio base station 3-i with an IP address. The correspondence table transmission unit 14 transmits the correspondence table together with the version to the radio base station 3-1. The radio base station 3-1 downloads the correspondence table together with the version from the network management device 2. The radio base station 3-i performs a health check intermittently with the directly connected radio base station 3-i ', and compares the versions of the correspondence table. When the version of the correspondence table is different, the radio base station 3-i downloads a new correspondence table together with the version from the radio base station 3-i ′, and notifies the network management device 2 of the completion of the download. The setting completion notification receiving unit 15 receives a notification indicating the completion of downloading of the correspondence table from the radio base stations 3-1 to 3-10.
[0028]
FIG. 3 shows the correspondence table created by the correspondence table creation unit 13. The correspondence table 21 associates the MAC address, IP address, and netmask of each radio base station 3-i with each other. The MAC address is a unique number recorded in the ROM of the radio base station 3-i, and is not changed and identifies the radio base station 3-i. The IP address is used for identifying the radio base station 3-i in the radio access network 1. The net mask is a numerical value used to divide the IP address into a network part that identifies the subnet 6-j and a host part that identifies the radio base station 3-i. That is, the logical product of the IP address and the subnet mask is the network part, and the logical product of the negation of the subnet mask and the IP address is the host part.
[0029]
For example, the wireless base station 3-1 has a MAC address “MAC-1”, an IP address “172.18.0.1”, and a netmask “255.255.255.248”. . The wireless base station 3-2 has a MAC address “MAC-2”, an IP address “172.18.0.2”, and a netmask “255.255.255.248”. The wireless base station 3-3 has a MAC address “MAC-3”, an IP address “172.18.0.3”, and a netmask “255.255.255.248”. The wireless base station 3-4 has a MAC address “MAC-4”, an IP address “172.18.0.4”, and a netmask “255.255.255.248”. The wireless base station 3-5 has a MAC address of “MAC-5”, an IP address of “172.18.0.5”, and a netmask of “255.255.255.248”. The wireless base station 3-6 has a MAC address of “MAC-6”, an IP address of “172.18.0.6”, and a netmask of “255.255.255.248”. The radio base station 3-7 has a MAC address of “MAC-7”, an IP address of “172.18.0.9”, and a netmask of “255.255.255.252”. The wireless base station 3-8 has a MAC address of “MAC-8”, an IP address of “172.18.0.10”, and a netmask of “255.255.255.252”. The wireless base station 3-9 has a MAC address of “MAC-9”, an IP address of “172.18.0.13”, and a netmask of “255.255.255.252”. The wireless base station 3-10 has a MAC address “MAC-10”, an IP address “172.18.0.14”, and a netmask “255.255.255.252”.
[0030]
The net mask is set for each sub-address, and the number of digits in the network part and the host part of the IP address can be different. Such assignment prevents exhaustion of addresses assigned to the plurality of radio base stations 3-1 to 3-10.
[0031]
FIG. 4 shows an embodiment of an IP address assignment method according to the present invention. The IP address assignment method is executed by the network management device 2 when the connection relationship between the radio base stations 3-1 to 3-10 is changed. First, the network management device 2 searches for all terminal radio base stations using a well-known vertical search algorithm (step S1), and determines whether or not the terminal radio base station is subnetted (step S2). ).
[0032]
When the network management apparatus 2 finds a terminal radio base station that is not subnetted (step S2; YES), the network management apparatus 2 determines the terminal radio base station and the highest radio base station that are not subnetted and have the greatest depth. Of the wireless base stations on the route to be connected, a set of wireless base stations that are not subnetted is subnetted (step S3). Further, the network management device 2 assigns serial IP addresses to the subnetted wireless base stations and derives a netmask. The network management device 2 further creates a correspondence table that associates the MAC address, IP address, and netmask of the wireless base station with each other (step S4).
[0033]
When the network management device 2 finds a terminal radio base station that is not subnetted (step S2; YES) or when step S4 is completed, all the radio base stations 3-1 to 3-10 It is investigated whether or not it is subnetted (step S5). When there is a radio base station that does not yet belong to the subnet (step S5; NO), the network management device 2 executes step S1 again, and repeats the step of subnetting and assigning an IP address to the radio base station 3-i. .
[0034]
According to the address assignment method of the present invention, it is possible to easily prevent exhaustion of IP addresses used in the radio access network 1.
[0035]
The network management device 2 transmits the correspondence table together with the version to the radio base station 3-1. The radio base station 3-1 downloads the correspondence table from the network management device 2. The radio base station 3-i intermittently performs a health check with the directly connected radio base station 3-i ′, and compares the versions of the correspondence table. When the version of the correspondence table is different, the radio base station 3-i downloads a new correspondence table from the radio base station 3-i ′ and notifies the network management device 2 of the completion of the download. The setting completion notification receiving unit 15 receives a notification indicating the completion of downloading of the correspondence table from the radio base stations 3-1 to 3-10.
[0036]
According to such an operation, it is preferable that the network management device 2 can always detect that a new IP address and netmask are set in the radio base stations 3-1 to 3-10.
[0037]
【The invention's effect】
The network management device and the address assignment method according to the present invention can prevent exhaustion of IP addresses when assigning IP addresses to radio base stations constituting a radio access network.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a radio access network system.
FIG. 2 is a block diagram showing an embodiment of a network management apparatus according to the present invention.
FIG. 3 is a table showing a correspondence table.
FIG. 4 is a flowchart showing an embodiment of an IP address assignment method according to the present invention.
[Explanation of symbols]
1: Radio access network 2: Network management devices 3-1 to 3-10: Radio base station 4: Local area networks 6-1 to 6-3: Subnet 10: Radio access network system 11: Subnet creation unit 12: IP address Allocation unit 13: correspondence table creation unit 14: correspondence table transmission unit 15: setting completion notification reception unit 21: correspondence table

Claims (8)

A subnet creation unit that divides a plurality of radio base stations forming a communication network into a plurality of prime subnets;
An address allocation unit that allocates addresses to radio base stations belonging to the plurality of subnets among the plurality of radio base stations,
The plurality of radio base stations are directly connected to only one radio base station of the plurality of radio base stations, unlike the highest radio base station, which is directly connected to the network management apparatus. A plurality of terminal radio base stations connected to
The plurality of subnets are respectively
One terminal radio base station of the terminal radio base stations;
One other end radio base station of the plurality of radio base stations;
A radio base station in a path connecting the one terminal radio base station and the one other radio base station,
The one other end radio base station is a radio base station connected to another radio base station belonging to another subnet, or the highest radio base station,
The other radio base station is a network management device different from the plurality of terminal radio base stations . In claim 1,
The address includes a network part and a host part,
The address assigned to a radio base station belonging to one of the plurality of subnets is:
The network parts are identical;
A network management apparatus, wherein the host part is formed of a minimum number of digits that can sufficiently identify a radio base station belonging to the one subnet, a network address, and a broadcasting address. In claim 2,
The network management device, wherein the number of radio base stations belonging to a subnet including the highest radio base station in the plurality of subnets is the largest in the plurality of subnets. In claim 3,
A correspondence table creating unit that creates a correspondence table associating the plurality of radio base stations with the addresses;
A correspondence table transmitting unit that transmits the correspondence table to the highest radio base station together with a version indicating the newness of the correspondence table;
The highest radio base station downloads the correspondence table together with the version from the network management device,
The plurality of radio base stations include a first radio base station that records a first correspondence table and a second radio base station that is directly connected to the first radio base station and records a second correspondence table. Including
The network management apparatus, wherein the first radio base station downloads the second correspondence table together with the version from the second radio base station when the first correspondence table is newer than the second correspondence table. Dividing a plurality of radio base stations forming a communication network into disjoint subnets;
Assigning addresses to radio base stations belonging to the plurality of subnets among the plurality of radio base stations,
The plurality of radio base stations are directly connected to only one radio base station of the plurality of radio base stations, unlike the highest radio base station, which is directly connected to the network management apparatus. A plurality of terminal radio base stations connected to
The plurality of subnets are respectively
One terminal radio base station of the terminal radio base stations;
One other end radio base station of the plurality of radio base stations;
A radio base station in a path connecting the one terminal radio base station and the one other radio base station,
The one other end radio base station is a radio base station connected to another radio base station belonging to another subnet, or the highest radio base station,
The other radio base station is an address assignment method different from the plurality of terminal radio base stations . In claim 5,
The address includes a network part and a host part,
The address assigned to a radio base station belonging to one of the plurality of subnets is:
The network parts are identical;
An address allocation method in which the host part is formed from a minimum number of digits that can sufficiently identify a radio base station belonging to the one subnet, a network address, and a broadcasting address. In claim 6,
The address allocation method, wherein the number of radio base stations belonging to a subnet including the highest radio base station among the plurality of subnets is the maximum among the plurality of subnets. In claim 7,
Creating a correspondence table associating the plurality of radio base stations with the addresses;
Transmitting the correspondence table to the highest radio base station together with a version indicating the newness of the correspondence table,
The highest radio base station downloads the correspondence table together with the version from the network management device,
The plurality of radio base stations include a first radio base station that records a first correspondence table and a second radio base station that is directly connected to the first radio base station and records a second correspondence table. Including
The first radio base station downloads the second correspondence table together with the version from the second radio base station when the first correspondence table is newer than the second correspondence table.

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