KR100295456B1 - How to provide internet protocol level connectivity between internet access terminals - Google Patents

Abstract

The present invention provides a subscriber terminal connected to the Internet with a unique Internet protocol address, and has a dial-up Internet access terminal with which a unique Internet protocol address is not assigned. A method for providing Internet protocol level connectivity, comprising: providing an IP level of connectivity between a terminal connected to the Internet and a dial-up terminal not connected to the Internet without a unique IP address, thereby providing Internet telephony (IT) and Internet Protocol (IP). In addition to fax, it is effectively used to provide access service between home subscriber terminals through the Internet in the future.

Description

How to provide internet protocol level connectivity between internet access terminals

The present invention relates to a method for providing Internet protocol level connectivity between Internet access terminals. More particularly, the present invention extends the function of a domain name system server to receive services such as Internet protocol fax and Internet telephony through the Internet. A method for providing protocol level connectivity.

Due to the rapid growth of the Internet and the development of high-speed Internet access technology based on Asynchronous Transfer Mode (ATM) and Asymmetric Digital Subscriber Line (ADSL), Internet Protocol (hereinafter referred to as IP), fax and Internet Telephony (hereinafter referred to as IT) are emerging as strong services. Such a service requires a communication environment that can always establish a connection to a counterpart subscriber terminal, such as a plain old telephone service (POTS) dial tone service.

In general, a dial-up terminal connecting to the Internet using an ADSL modem includes an Internet Service Provider (ISP) and a Point-to-Point Protocol (hereinafter referred to as ISP) when connecting to the Internet. PPP) establishes a session, dynamically assigns an IP address, and connects to the Internet. When the connection is closed, the IP address is returned back to the ISP. Therefore, the dial-up terminal has a unique IP address when connected to the Internet, and the subscriber can use the desired service or obtain necessary information through the Internet.

In such a conventional Internet connection of a dial-up terminal, a subscriber establishes a PPP session to an ISP and receives an IP address and accesses the Internet only when the subscriber of the dial-up terminal desires it.

On the other hand, if the subscriber of the source terminal (the terminal that starts the IT service) connected to the Internet wants to use the same service as the subscriber of the destination terminal and the IT, if the destination terminal is a dial-up terminal and is not connected to the Internet, the ISP A PPP session is established between an Internet access server (hereinafter referred to as IAS) and a destination terminal of a network, and a destination terminal may be assigned an unique IP address from an ISP and connected to the Internet to start an IT service.

Such a communication environment is possible when two subscriber stations are connected to the Internet and the IP level of connectivity between terminals is provided. That is, in an environment where two subscriber stations are connected to the Internet with unique IP addresses, and a connection is established to IP layers between terminals through the Internet, and IP packets can be transmitted / received, it is necessary to know only the IP addresses of the other subscriber terminals. You can start However, although the terminal starting the IT service is connected to the Internet with a unique IP address, the counterpart terminal is a dial-up terminal that is dynamically allocated an IP address from an ISP and connected to the Internet, and may not be connected to the Internet. In this case, in order to provide IP level connectivity between two terminals, an ISP providing an Internet access service to a destination terminal should identify the destination terminal, establish a PPP session with the terminal, and dynamically assign an IP address.

Accordingly, the present invention has been made in view of the above-described conventional situation, and the subscriber terminal connected to the Internet with a unique internet protocol address has an Internet protocol level connectivity at any time with a dial-up Internet access terminal which is not assigned a unique Internet protocol address. It is an object of the present invention to provide a method for providing Internet protocol level connectivity between Internet access terminals that can be established and communicated.

1 is a diagram illustrating a network configuration and a protocol stack to which the present invention is applied.

2 is a signal flow diagram illustrating a service providing process according to the present invention.

3 and 7 are flowcharts illustrating an operation process of the terminal A during the service providing process according to FIG. 2.

4 and 6 are flowcharts illustrating an operation of a dial-up-domain name system (DU-DNS) server during a service providing process according to FIG. 2.

FIG. 5 is a flowchart illustrating an operation process of the Internet access server (IAS) during the service providing process according to FIG. 2.

<Description of the reference numerals for the main parts of the drawings>

10: terminal A 12: the Internet

14: Internet service provider network (ISP network)

16: Internet access server (IAS) 18: ATM network

20: Digital Subscriber Line Multiplexer (DSLAM)

22: terminal B

24: Dial-up Domain Name System Server (DU-DNS Server)

In order to achieve the above object, a method of providing Internet protocol level connectivity between Internet access terminals according to a preferred embodiment of the present invention includes a terminal A as a source terminal connected to the Internet with a unique Internet protocol address, and the Internet protocol address. A method for providing Internet protocol level connectivity between a terminal B as a dial-up terminal which is dynamically allocated to the Internet, the method comprising:

As a subscriber of the terminal A inputs the domain name of the terminal B, a domain name system query packet is generated by a domain name system resolver of the terminal A to the terminal B via the Internet. The first process of sending,

Upon receiving the domain name system query packet, a dialup-domain name system server of the Internet service provider network to which the terminal B belongs checks whether there is a type A resource record (RR) corresponding to the domain name of the terminal B; 2 courses,

If the type A RR is found, the terminal A returns an Internet protocol address of the terminal B through a domain name system response (DNS RESPONSE) packet, whereas if the type A RR is not present, a type ATMA corresponding to the domain name is returned. A third step of checking if there is an RR,

If the type ATMA RR is not present, a name error is sent to the terminal A through the domain name system response packet. If there is the type ATMA RR, an Internet protocol address assignment request message is sent to an Internet access server to transmit the Internet protocol address to the terminal B. Assigning and sending the assigned Internet Protocol address to the dial-up domain name system server;

And a fifth process of generating a type A RR for the terminal B by the dial-up domain name system server and sending the Internet protocol address of the terminal B to the terminal A through the domain name system response packet.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a network configuration and a protocol stack to which the present invention is applied, and terminal A 10 is a source terminal connected to the Internet 12 with a unique IP address, and terminal B 22 is a source terminal. A dial-up terminal that accesses the Internet 12 by dynamically assigning an IP address by establishing an IAS 16 located in an ISP network 14, an ATM virtual channel (hereinafter referred to as VC), and a PPP session. Corresponds to the terminal. The remote ADSL transmission unit (hereinafter referred to as ATU-R) of the terminal B 22 is a subscriber-side ADSL modem and a digital subscriber line access multiplexer (hereinafter referred to as DSLAM) and an ADSL loop. form a loop. The terminal B 22 does not currently have a unique IP address and is not connected to the Internet 12. Here, the DSLAM terminates the ADSL signal and has a multiplexing / demultiplexing function of the subscriber ATM VC.

The dial-up terminal (or dial-up Internet access terminal) 22 establishes a PPP session with the IAS 16 of the ISP network 14 via an ADSL modem, and dynamically receives an IP address from the IAS 16. It connects to the Internet 12 and can usually be a personal computer (PC). The protocol structure between the dial-up terminal 22 and the IAS 16 follows PPP / ATM.

The ISP is an operator that dynamically assigns an IP address to the dialup terminal 22 through the IAS 16 and provides the Internet access service to the dialup terminal 22. The IAS 16 is an Internet access server operated by the ISP. The IAS 16 has functions of a PPP server and an IP router to perform dynamic IP address assignment and routing of IP packets to a terminal.

In addition, the IP connectivity between the terminals or the provision of the IP connectivity is that the two terminals are connected to the Internet 12 with a unique IP address, and the IP router and IAS (located at the Internet 12 and the ISP network 14) are located. This means that IP packets can be transmitted and received between terminals through the IP packet routing function of 16).

In the communication environment as shown in FIG. 1, in order for a subscriber of terminal A 10 to start a service such as IT and a subscriber of terminal B 22, IP level connectivity must be established between IAS 16 and terminal B 22 first. . Herein, the IP connectivity between the IAS 16 and the terminal B 22 is set so that the terminal B 22 is assigned an IP address from the IAS 16 and connected to the Internet 12, and the IAS 16 is connected to the terminal. Routing the IP packet destined for B 22 toward terminal B 22 means that the IP packet can be delivered to terminal B 22, and that the IP packet can be sent from terminal B 22 to the Internet 12. To this end, first, an ATM VC and a PPP session are established between the Internet access server 16 and the terminal B 22.

2 is a service providing procedure between network components proposed in the present invention to provide end-to-end IP connectivity between terminal A 10 and terminal B 22 in a communication environment as shown in FIG. Shows. The dial-up domain name system (DU-DNS) server 24 shown in FIG. 2 extends the functions of a conventional domain name system (DNS) server. To explain.

Detailed functional operation flowcharts of the network elements according to the service providing procedure of FIG. 2 are the same as those of FIGS. 3, 4, 5, 6, and 7. 3 and 7 are operations of the terminal A 10, 4 and 6 are operations of the DU-DNS server 24, and FIG. 5 is a flowchart illustrating operations of the IAS 16 of the ISP network 14. .

The service providing procedure of FIG. 2 and the service providing procedure for providing IP connectivity between the terminal A 10 and the terminal B 22 with reference to FIGS. 3 to 7 are performed by a DNS resolver of the terminal A 10. Begins by sending a Domain Name System Query (DNS QUERY) packet with the domain name of B 22 towards the Internet 12 (2-1), and the terminal B 22 is assigned a unique IP address from the ISP (2-1 to 2-7) is terminated when the domain name system response (DNS RESPONSE) packet containing the IP address or name error of the terminal B 22 is returned to the terminal A 10 ( 2-8). Detailed operation description thereof will be described by dividing from Step 1 to Step 6 as follows.

First, in the embodiment of the present invention, if a dial-up Internet access terminal such as terminal B 22 is connected to the Internet 12, terminal B 22 is assigned an IP address from an ISP and has a unique IP address. If it is not connected to the Internet 12, it is assumed that it does not have an IP address. The communication protocol between the terminal B 22 and the IAS 16 follows the PPP / ATM protocol structure, and establishes an ATM virtual channel (ATM VC) using a user network interface (ATM UNI) signaling protocol. Terminal B 22 will be described on the assumption that the power is in the "ON" state and can receive the SETUP message of the signaling protocol.

Step 1: When the subscriber of the terminal A (10) enters the domain name of the terminal B 22 to be accessed in the initial screen of the application service, such as IT, the DNS resolver of the terminal A (10) is a domain name system query (DNS QUERY) ) Generate a packet (see 3-1 in FIG. 3) and send a Domain Name System Query (DNS QUERY) packet to the Internet 12 (see 2-1 in FIG. 2 and 3-2 in FIG. 3). At this time, the DNS QUERY packet is a request for a type A RR. That is, 'QUERY' in the OPCODE field of the DNS QUERY packet, 'Domain name' of the terminal B in the QNAME field, 'IN' indicating the Internet class in the QCLASS field, and 'A' indicating the IP address in the QTYPE field. Filled with.

Step 2: The DU-DNS server 24 of the Internet service provider network 14 to which the terminal B 22 belongs to the domain name system query (DNS QUERY) packet generated at the terminal A 10 via the Internet 12. (See 2-2 in FIG. 2).

Step 3: The DU-DNS server 24 having received the Domain Name System Query (DNS QUERY) packet checks whether there is a type A RR corresponding to the domain name of the terminal B 22 by referring to a database maintained by the DU-DNS server 24. (See 4-1 in Figure 4). The type A RR is a record for storing a pair of a domain name and an IP address of the terminal. If the type A RR is present, the IP address of the terminal B 22 is returned to the terminal A 10 through a domain name system response (DNS RESPONSE) packet (see 2-7 in FIG. 2 and 4-2 in FIG. 4). The process proceeds to step 6, which will be described later, to perform the operation of step 6.

If there is no type A RR, it is checked whether there is a type ATMA RR corresponding to the domain name (refer to 4-3 in FIG. 4). Here, the type ATMA RR is a record that stores a pair of the domain name and the ATM address of the terminal. If there is no type ATMA RR, a Name Error is sent to the terminal A 10 through a Domain Name System Response (DNS RESPONSE) packet (see 4-5 in FIG. 4 and 2-7 in FIG. 2). Proceed to perform the operation of step 6. Here, the name error indicates that there is no address information corresponding to the domain name of the terminal B 22.

If the type ATMA RR is present, an IP address assignment request message is sent to the IAS 16 (see 2-3 in FIGS. 2 and 4-4 in FIG. 4). The IP address assignment request message includes the domain name and ATM address of the terminal B 22.

Step 4: Upon receiving the IP address assignment request message from the DU-DNS server 24, the IAS 16 sends an ATM UNI SETUP message to the terminal B and sets the terminal B and the ATM VC (Figs. 2-4 and 5-). 1). The IAS 16 establishes a PPP session and assigns an IP address after the ATM VC is established (see 2-5 in FIG. 2 and 5-2 in FIG. 5). At this time, the IAS 16 or the UE may start a PPP Link Control Protocol (LPP) for establishing a PPP session. Thereafter, the IAS 16 passes the IP address allocated to the terminal B to the DU-DNS server 24 through an IP address assignment response message (see 2-6 in FIG. 2 and 5-3 in FIG. 5). The IP address assignment response message includes the domain name of the terminal B 22 and the IP address.

Step 5: The DU-DNS server 24 receiving the IP address assignment response message from the IAS 16 generates a type A RR from the domain name and the IP address of the terminal B 22 and stores it in its database ( 6-1 in FIG. 6), the IP address of the terminal B 22 is returned to the terminal A 10 through a domain name system response (DNS RESPONSE) packet (2-7 in FIG. 2 and 6- in FIG. 6). 2).

Step 6: Terminal A 10 receiving the Domain Name System Response (DNS RESPONSE) packet interprets the Domain Name System Response (DNS RESPONSE) packet and informs the application of the IP address or name error of terminal B 22. (2-8 in FIG. 2, see FIG. 7).

In order to support the service providing procedure as described above, network components have a function requirement to be added or changed to an existing function. First, DU-DNS server is an extension of existing DNS server and has the following functions.

First, it has a type ATMA RR storage function for dial-up terminal identification. When the DU-DNS server 24 receives a Domain Name System Query (DNS QUERY) packet, a terminal identifier is required to identify a dial-up terminal that is not connected to the Internet 12, such as terminal B 22. Although the IP address or the domain name of the terminal may be considered as the identifier of the terminal, the dial-up terminal that is not assigned an IP address may use the domain name as the identifier of the terminal. However, since a conventional DNS server stores a pair of domain names and IP addresses, a dial-up terminal that is not assigned an IP address does not have a type A RR, and thus no domain name is stored.

On the other hand, the DU-DNS server 24 employed in the present invention is a terminal using a type ATMA RR which is a record for storing a pair of domain name and ATM address defined in ATM Name System (ANS) of ATM Forum. The domain name of is used as an identifier of the terminal. That is, the DU-DNS server 24 can maintain the domain name regardless of the IP address assignment of the terminal by always storing the type ATMA RR for the dial-up terminal having the ATM address as the terminal B 22 in its database. Make sure

If the terminal B 22 is not connected to the Internet 12, only the ATMA RR is stored in the DU-DNS server 24, and the type A RR is added after the terminal is assigned an IP address. Therefore, the DU-DNS server 24 according to the present invention should be able to store not only the type A RR of the conventional DNS server but also the type ATMA RR. At this time, the TTL field of the type A RR and the ATMA RR is set to '0', which indicates the caching of the type A RR and the type ATMA RR of the dial-up terminal such as the terminal B 22 by another DNS server or the DNS resolver of the terminal. In order to prevent this, only the DU-DNS server 24 having authority for a specific DNS zone can perform the above-described service procedure of steps 1 to 6.

Secondly, it has a communication function with the Internet access server 16, which will be described in detail as follows. If the DU-DNS server 24 has only an ATM address corresponding to the domain name of the terminal B 22 and does not have an IP address, the DU-DNS server 24 makes an IP address assignment request to the IAS 16, and the IP from the Internet access server 16. It must be able to receive an address assignment response. For this purpose, an IP address assignment request message and an IP address assignment response message are defined and used. The IP address assignment request message is sent from the DU-DNS server 24 to the IAS 16 and the domain name of the terminal B 22 and the ATM. An address is included, and an IP address assignment response message is sent from the IAS 16 to the DU-DNS server 24 and includes the domain name and IP address of the terminal B 22. In order to define the format of the IP address assignment request message and the IP address assignment response message and to transmit the message, the existing DNS protocol may be extended or a new protocol may be defined and used.

And, when the operation of the DU-DNS server 24 having the above function will be described, the domain name system query (DNS QUERY) packet that the DU-DNS server 24 regards as a connection request to the terminal B (22) Is a request for an IP address corresponding to a domain name. When the DU-DNS server 24 receives such a Domain Name System Query (DNS QUERY) packet, it first searches for a type A RR for the requested domain name from its database. (4-1 in Figure 4). If there is a type A RR, terminal B 22 assumes that it is currently connected to the Internet 12 and returns an IP address for the domain name through a Domain Name System Response (DNS RESPONSE) packet (2- in FIG. 2). 7, 4-2 in FIG. 4). If there is no type A RR, it checks whether there is a type ATMA RR corresponding to the domain name (4-3 in FIG. 4), and if there is an ATMA RR, sends an IP address assignment request message to the IAS 16 (2- in FIG. 2). 3, 4-4 in FIG. 4) if there is no ATMA RR, a domain name system response (DNS RESPONSE; name error in this case) is returned to the terminal A 10 (4-5 in FIG. 4). When the IP address allocation request message is sent to the IAS 16, the DU-DNS server 24 must wait until the IP address assigned to the terminal B 22 is returned from the IAS 16. After the IP address is returned from the IAS 16 through an IP address assignment response message, a type A RR is recorded in its database (6-1 in FIG. 6), and then the terminal is transmitted through the domain name system response (DNS RESPONSE) packet. Return the IP address of (2-7 in Fig. 2, 6-2 in Fig. 6).

Therefore, when the DU-DNS server 24 receives the Domain Name System Query (DNS QUERY) packet, it should be able to perform the above operation procedure. In particular, there is no type A RR for the terminal B 22 and no type ATMA RR. If so, IAS 16 requests IP address assignment for UE B 22 and sends a Domain Name System Response (DNS RESPONSE) packet to UE A 10 until an IP address assignment response message is received from IAS 16. You have to wait without sending it.

On the other hand, the function that the IAS 16 of the ISP network 14 should have a first ATM connection setup request function to the terminal B (22). That is, when the IAS 16 receives the IP address allocation request message for the terminal B 22 from the DU-DNS server 24, the IAS 16 refers to the ATM address of the terminal B 22 toward the terminal B 22 toward the ATM UNI SETUP. Send a message and establish an ATM VC with terminal B 22. After the terminal B 22 and the ATM VC are configured, a PPP session for IP address allocation must be established. The PPP LCP for establishing a PPP session may be performed by the IAS 16 or the terminal B 22 first. The PPP entity of the IAS 16 should be able to allocate an IP address through the IP Control Protocol (IPCP) protocol through a PPP link establishment phase and an authentication phase.

The IAS 16 should be able to assign an IP address to the terminal B 22 and then return the IP address of the terminal B 22 to the DU-DNS server 24 through an IP address assignment response message. The IP address assignment request message and the IP address assignment response message are the same as described in the functional requirements of the DU-DNS server 24 described above.

In addition, the function that the dial-up terminal B 22 should have should be able to accept the ATM UNI SETUP message and set the VC in order to set the IAS 16 and the ATM VC. In addition, in order to establish a PPP session with the IAS 16, the PPP entity of the terminal should be able to be assigned an IP address through the IPCP protocol through a PPP link establishment step and a PPP authentication step.

Meanwhile, in addition to the functional requirements of the network component, it is efficient to separately configure and manage domains for dial-up terminals such as terminal B. That is, a domain (eg, dial-up domain) for exclusively managing the dial-up terminal is defined as a subdomain of the ISP domain, and the domain name of the terminal is managed to have uniqueness in the subdomain. Once these subdomains are defined, it is efficient to manage them as separate, independent Domain Name System Zones.

According to the present invention as described above, by providing IP-level connectivity between a terminal connected to the Internet and a dial-up terminal without a unique IP address, the home subscriber is not only connected to the IT, IP fax, but also through the Internet in the future. It is effectively used to provide terminal to terminal access service.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (7)

A method for providing an Internet protocol level of connectivity between a terminal A as a source terminal connected to the Internet with a unique Internet protocol address and a terminal B as a dial-up terminal which is dynamically allocated to the Internet protocol address and connected to the Internet. A first step of generating a domain name system query packet by the domain name system resolver of the terminal A and transmitting the generated domain name query packet to the terminal B through the Internet as the subscriber of the terminal A inputs the domain name of the terminal B; A second step of checking whether there is a first type corresponding to the domain name of the terminal B in a dial-up-domain name system server of the Internet service provider network to which the terminal B belongs when receiving the domain name system query packet; If the first type is found, the terminal A transmits the Internet protocol address of the terminal B to the terminal A through a domain name system response packet. If the first type is not present, it is checked whether there is a second type corresponding to the domain name. The third process, If the second type is not present, a name error is transmitted to the terminal A through the domain name system response packet. If the second type is present, an Internet protocol address assignment request message is sent to the Internet access server, thereby transmitting the Internet protocol address to the terminal B. A fourth process of assigning and sending the assigned Internet Protocol address to the dial-up domain name system server; And a fifth process of generating a first type for the terminal B by the dial-up domain name system server and sending the Internet protocol address of the terminal B to the terminal A through the domain name system response packet. Method of providing Internet protocol level connectivity between the Internet access terminals. The method of claim 1, wherein the domain name system query packet comprises an opcode field in which a query is recorded, a queue name field in which a domain name of the terminal B is recorded, a queue class field in which an internet class is recorded, and an internet protocol address. And providing a recorded queue type field to move between the terminal A and the terminal B through the Internet. The method of claim 1, wherein the domain name system query packet is a request for the first type. 4. The method of claim 3, wherein the first type is a record for storing a pair of a domain name and an internet protocol address of the terminal. 2. The method of claim 1, wherein the Internet protocol address assignment request message includes a domain name of the terminal B and an internet protocol address. The terminal of claim 1, wherein the dial-up domain name system server uses the terminal's domain name as an identifier for identifying the terminal B that is not connected to the Internet without a unique Internet protocol address. And storing the second type in advance in its database for use as an identifier of the Internet protocol level. 7. The method according to claim 1 or 6, wherein the second type is a record for storing a pair of the domain name and the ATM address of the terminal B.