KR100921331B1 - System and method for using IP address per virtual line in internet access service using asymmetric digital subscriber line - Google Patents

Abstract

The present invention relates to a system and method for limiting the use of IP addresses for each virtual line in an internet access service using an asymmetric digital subscriber line. The IP allocation request signal is received for a plurality of asymmetric digital subscriber line (ADSL) modems that receive an IP allocation request signal for transmission to the copper line and a group matching any number of the asymmetric digital subscriber line modems. A plurality of digital subscriber line access multiplexers (DSLAMs), a network access server (NAS) receiving the IP allocation request signal from each of the digital subscriber line access multiplexers, including the subscriber's virtual line information, and transmitting the received information; Via the Internet from the network access server. After determining whether the request exceeds the number of IP addresses contracted by the subscriber by using the received IP allocation request signal, if not exceeded, the IP is allocated to the subscriber station. Dynamic Host Configuration Protocol (DHCP) for temporary allocation and information database for storing the subscriber's virtual line information, contracted IP number, IP number already assigned and IP address assigned.

Description

System for limiting the number of internet protocol address according to virtual connection in asymmetric digital subscriber line internet access service}

1 is an overall configuration diagram of an ADSL Internet access service using DHCP according to the present invention.

2 is an overall flowchart for providing an ADSL Internet access service using DHCP according to the present invention.

3 is a flowchart for assigning an IP address of a DHCP server according to the present invention;

The present invention relates to an apparatus and method for limiting the use of IP addresses per virtual line in an internet access service using an asymmetric digital subscriber line. The present invention relates to a number of IP addresses contracted with a subscriber using a Dynamic Host Configuration Protocol (DHCP) server. If there is an excess IP address allocation request, a private line is assigned, and if it is not exceeded, it is determined whether the IP address is in use and assigned. The present invention relates to a device and a method for restricting the use of a star IP address.

High speed internet access service using an asymmetric digital subscriber line (hereinafter referred to as ADSL) A subscriber must have a certified IP address to access the Internet.

In general, a subscriber to a high-speed Internet access service is assigned an IP address through a Point-To-Point (PPP) connection to access the Internet. However, the method of assigning an IP address through a Point-To-Point (PPP) connection is inconvenient in use due to the burden on the system such as maintaining and managing a PPP session and the authentication process. The method of assigning an IP address using the Dynamic Host Configuration Protocol is preferred.

DHCP is a protocol that allows network administrators to centrally manage and assign IP addresses on an organization's network. Unlike PPP, DHCP does not need to maintain a PPP session and operates as a client server structure. This DHCP client is used to exchange configuration information with a DHCP server on the network. Thus, the system is less burdensome and IP addresses can be assigned without the need for an authentication process.

However, although DHCP is convenient in use, it can be disadvantaged by accessing the Internet by being assigned an IP address without permission, or by randomly distributing an abnormal IP address. Paralyzed and easy to hack there was a security problem.                         

In order to solve this problem, conventionally, in order to restrict an unauthorized IP address, a hardware address (MAC address) of a subscriber station is managed and authenticated by a DHCP server, so that an IP address is assigned only to a normal subscriber that matches the corresponding address.

However, if the hardware address is changed due to a problem such as changing the LAN card of the subscriber station or exchanging a new system, it is possible to connect to the Internet only by changing and registering the changed hardware address of the subscriber station stored in the DHCP server. There was this.

In addition, when the IP address is not assigned, there is a problem in that the load of the DHCP server is increased by continuously requesting the IP allocation to the DHCP server.

An object of the present invention for solving the above problems, regardless of the change in the hardware address of the subscriber station, by limiting the number of IP addresses that can be allocated for each ADSL line in the DHCP server, blocking the IP address allocation request exceeding the contract To prevent unauthorized use of your IP address.

In addition, when an IP address is not assigned, a private IP is arbitrarily assigned to prevent a continuous IP address assignment request from a DHCP server, thereby reducing the load of the DHCP server.

The present invention for achieving the above object is a plurality of subscriber stations for subscribers to attempt to access the Internet, and a plurality of asymmetric digital subscriber lines for receiving the IP allocation request signal for the Internet access from each of the subscriber terminals to transmit to the copper line (ADSL) a plurality of digital subscriber line access multiplexers (DSLAMs) receiving the IP allocation request signal for a group matching any number of modems, the asymmetric digital subscriber line modems, and each of the digital A network access server (NAS) receiving the IP allocation request signal from a subscriber line access multiplexer and including the subscriber's virtual line information, and transmitting the IP allocation request signal, and using the IP allocation request signal received from the network access server through the Internet Exceeds the number of IP addresses contracted by the subscriber After determining whether it is a request, if not exceeded, the IP is allocated to the subscriber station, and if exceeded, the dynamic host configuration protocol (DHCP) for temporarily allocating the private IP, and the subscriber's virtual line information and contract And an information database for storing the number of IPs already assigned, the number of IPs already allocated and the IP addresses assigned.

The above and other objects and features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an overall configuration diagram of an ADSL internet access service system using DHCP according to the present invention, wherein the ADSL internet access service system using DHCP includes a user terminal (101, 109), an ADSL modem (102, 110), and a digital subscriber line connection. Multiple Subscriber Line Access Multiplexer (hereinafter referred to as DSLAM) 104, Network Access Server (hereinafter referred to as NAS) 105, Dynamic Host Configuration Protocol (hereinafter referred to as DHCP) Server 107, information database 108 is provided.

The user terminals 101 and 109 refer to computers for attempting to access the Internet, and the ADSL modems 102 and 110 transmit the ADSL signals for the Internet connection from the user terminals 101 and 109 to the DSLAM 104. do.

The DSLAM 104 receives the ADSL signal transmitted from the above-described ADSL modems 102 and 110 through the copper line 103 and transmits it to the NAS 105. Here, the DSLAM 104 is a network equipment usually installed in a telephone station, receives signals from digital subscriber line connections of various customers, and sends signals to a high speed backbone line using multiplexing techniques.

The NAS 105 is a system specialized to be connected to a network. The NAS 105 receives a DHCP packet for each of the user terminals 101 and 109, includes virtual line information, and sends the corresponding DHCP packet to the DHCP server 107 through the Internet network 106. To send.

The DHCP server 107 stores the virtual line information from the user terminals 101 and 109, analyzes the DHCP packet received from the NAS 105 described above, and, if there is an IP address assignment request, contracts the IP address. If the number is exceeded, the IP address allocation is restricted by allocating a private IP address if exceeded and assigning the corresponding IP address if exceeded.

The information database 108 includes subscriber line information and subscriber information, the number of allocated IP addresses, the number of contracted IP addresses, the assigned IP address information, the IP address in use, and the IP address information in use.

2 is an overall flowchart for providing an ADSL Internet access service using DHCP according to the present invention.

First, the user terminal 101 sends a DHCP packet including a discovery message to the DHCP server 107 via the ADSL modem 102, the DSLAM 104, and the NAS 105 in order to attempt an internet connection. Send ①. In this case, the discovery message includes a message requesting the DHCP server 107 to assign an IP address.

The DHCP server 107 checks the number of IP addresses contracted from the information database 108 in response to the discovery message transmitted from the user terminal 101, checks whether the number of IP addresses to be allocated is exceeded and the contract is exceeded. It is determined whether or not an IP address allocation request is made, and an offer message including the determination result is transmitted to the user terminal 101 via the NAS 105, the DSLAM 104, and the ADSL modem 102. .

The user terminal 101 transmits a request message back to the DHCP server 107 via the ADSL modem 102, the DSLAM 104, and the NAS 105 again, using the assigned IP address. The IP address assigned by the DHCP server 107 determines whether the IP address may be used, and if it is available, an ACK message is available, and if it is not available, the NAK message is stored in the NAS 105, the DSLAM 104, and the ADSL modem 102. ④ to the user terminal 101 via.

The DHCP message (Discover, Request) transmitted from the subscriber terminal to the DHCP server always checks the information of the virtual line used by the subscriber in the NAS 105 and is included in the DHCP message and transmitted to the DHCP server.

3 is a flowchart for assigning an IP address of a DHCP server according to the present invention.

The DHCP server 107 receives a DHCP packet from the user terminal 101 (S201). It is determined whether the received DHCP packet is requesting an IP address assignment (S202), and if the IP address assignment request packet, the user terminal 101 requesting the IP address assignment checks which virtual line is used. (S203), the number of IP addresses contracted with the user terminal 101 is checked.

Thereafter, the number of IP addresses already assigned to the user terminal 101 is checked from the information database 108 (S204), and it is determined whether the number of allocated IP addresses exceeds the contracted IP address number (S205).

When the number of IP addresses contracted to be allocated to the user terminal 101 is exceeded in step S205 described above, it is determined whether an unused IP address exists by checking whether an already allocated IP address is used (S206). (S207). On the other hand, if the number of IP addresses contracted to assign to the user terminal 101 does not exceed, select and assign an IP address among the unassigned IP addresses (S212), and increase the number of allocated IP of the corresponding line by 1 , The corresponding IP address and the corresponding line information are recorded in the information database 108 (S213).

If there is an unused IP address in the above-described step (S207), by selecting the IP address with the least rental time remaining (S208), the existing usage information such as the line information, contract period, and the like previously allocated and used of the selected IP address is deleted. Then, the assignment state of the corresponding IP address is released (S209).                     

Here, when the user terminal 101 using the already assigned IP address is terminated, if the DHCP release packet including the IP address being used is not transmitted to the DHCP server 107, the corresponding IP address is not recovered and the remaining rental It is recorded as assigned for some time. This IP address is called unused IP address.

On the other hand, if the unused IP address does not exist, by selecting a private IP address that can not be temporarily connected to the Internet (S210), it blocks the incoming IP address allocation request to the DHCP server 108 continuously.

By outputting the user information of the corresponding line assigned the private IP address (S211), the configuration information is configured with the set IP rental time using information such as the assigned IP address, the number of contract IP address of the subscriber station 101, and the like. In step S214, the DHCP response packet is transmitted to the IP address allocation request of the user terminal 101 to provide an IP address (S215).

As described above, an apparatus and method for limiting the use of IP addresses for each virtual line in an Internet access service using an asymmetric digital subscriber line according to the present invention, the IP address allocation exceeding the number of IP addresses contracted through the virtual line information By blocking the request, it prevents unauthorized use of the IP address.

In addition, if there is an IP address allocation request exceeding the number of contracted IP addresses, by temporarily assigning a private IP, the load on the DHCP server is reduced, and the existence of an unused IP among the allocated IPs is checked to allocate an unused IP. By doing so, efficient IP management is possible.

In addition, a preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and changes are the following claims It should be seen as belonging to a range.

Claims (2)

A plurality of subscriber stations for subscribers to attempt to access the Internet; An asymmetric digital subscriber line (ADSL) modem for receiving an IP allocation request signal for accessing the Internet from each subscriber station and transmitting it to a copper line; A network access server (NAS) receiving the IP allocation request signal from the asymmetric digital subscriber line modem through a digital subscriber line access multiplexer (DSLAM) and including the subscriber's virtual line information; DHCP, which receives the IP allocation request signal including the virtual line information from the network access server, determines whether the request exceeds the number of IP addresses contracted by the subscriber. Dynamic Host Configuration Protocol) server; And A database of information storing the subscriber's virtual line information, contracted IP number, already assigned IP number and assigned IP address, The DHCP server If exceeding, check whether the IP address already assigned to the subscriber is used, and if the unused IP address does not exist, temporarily assign a private IP address, which is impossible to access the Internet, to the subscriber station. If an unused IP address exists, the unused IP is assigned to the subscriber station. Restriction system of IP address per virtual line in internet access service using asymmetric digital subscriber line. A receiving step of receiving an IP allocation request signal from a subscriber; Confirming the line information of the subscriber who has requested the IP allocation; It checks whether the number of IPs that can be allocated is left by checking the number of IPs contracted by the subscriber.If the number of IPs is not exceeded, the IP is allocated to the subscriber, and when the number of IPs is exceeded, whether or not the already allocated IP is used. Confirming a first allocation step; A second allocating step of allocating a private IP temporarily unavailable to the Internet if an unused IP does not exist among the already allocated IPs, and assigning an unused IP to the subscriber if an unused IP exists; And When the allocation is completed, the method for limiting the use of IP address for each virtual line in an internet access service using an asymmetric digital subscriber line including storing the allocated subscriber information, subscriber line information, and allocated IP information.

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