KR100397091B1 - NETWORK ACCESS DEVICE FOR SUPPORTING VoIP AND METHOD THEREOF - Google Patents

Abstract

The present invention relates to a network access device and a method for allocating a public IP address to a user terminal to which a local IP address is assigned to use a VoIP service.

The present invention provides a public IP address storing unit for storing at least one public IP address, an internal network interface unit for receiving a request from a user terminal, and determining whether the request from the user terminal is a request for a service associated with H.323. A packet inspecting unit, and if the request from the user terminal is a request for a service associated with H.323, providing the public IP address to the user terminal so that the user terminal sets the public IP address to its own IP address. It provides a network connection device including an IP address providing unit.

According to the present invention, a private IP address is allocated through a network access device such as a network address translator and an IP sharer to access the Internet, and when the VoIP service is used, the public IP address is allocated again to minimize the use of the public IP address. It can provide VoIP service to user.

Description

Network access device and method for supporting voice over IP {NETWORK ACCESS DEVICE FOR SUPPORTING VoIP AND METHOD THEREOF}

The present invention relates to a network access device and a method for providing a network access to a user, and more particularly, to assign a public IP address to a user terminal assigned a local IP address, The present invention relates to a network connection device and a method for enabling a service.

With the spread of the Internet, the assignment of IP addresses has become an important issue. The Internet is a network based on the TCP / IP protocol. According to the TCP / IP protocol protocol, each device connected to the Internet is identified by a unique IP address. That is, only one host corresponding to one IP address should exist on the Internet. These IP addresses consist of four bytes. Due to the explosive development of the Internet, it is now difficult to assign a unique IP address to every terminal that accesses the Internet.

In order to solve this problem, new IP protocols such as IPv6, which increase the data size of IP addresses, are being discussed. In addition, network address translator (NAT) and IP router (IP router) are widely used to solve the above problems, and in fact, a large number of terminals are currently connected to the Internet through a network address translator or IP router. have.

The network address translator is an IP address translator that converts a private IP address into a public IP address. The public IP address is an IP address uniquely identifying the terminal on the Internet, and is an IP address assigned by a valid IP address assigning authority. The worldwide assignment of public IP addresses is handled by The Internet Corporation for Assigned Names and Numbers (ICANN). Private IP addresses are used only within the local network and cannot be used to access an external network. The private IP address may be assigned any IP address, but usually an IP address of the form 192.X.X.X is assigned.

As mentioned earlier, the lack of public IP addresses makes it difficult to assign public IP addresses to all terminals. Therefore, a plurality of terminals connected to a local network in a home or company are assigned a private IP address, and when the terminals communicate with a server connected to an external network, the network address translator stores the private IP address in a communication packet. The method of changing to a public IP address and sending it to the external server is used. At this time, the conventional network address translator inspects a source IP address field of a received IP packet and changes the source IP address to a public IP address. In addition, IP address translation is performed on packets input from the external network to the internal network, and transmitted to the appropriate terminals of the internal network.

IP routers also use private IP addresses for terminals connected to the internal network, and share one or more public IP addresses when the terminals communicate with the external network.

Meanwhile, as the Internet is widely used today, various services using the Internet have appeared. Among these services, a voice communication service using a packet-based network such as the Internet, instead of a Switched Circuit Network (SCN) including a conventional Public Switched Telephone Network (PSTN), is also available. have. As one of voice communication services, Voice over Internet Protocol (VoIP) service is a service for transmitting voice using an Internet Protocol (IP) network. This VoIP service is implemented using the H.323 standard.

1 is a block diagram illustrating a protocol stack of the H.323 protocol.

H.323 is a component for providing multimedia communication such as audio, video, and data communication in real-time using a packet network including the Internet Protocol (IP); and Standard for protocols, established by ITU-T.

As shown in FIG. 1, the H.323 protocol stack 115 includes an RTP 105, an RTCP 108, an H.225 RAS 109, an H.225 call signaling 110, and an H.245. Control signaling 111, G.711, G.729, G.723.1 (106), H.261, H.263 (107), audio application 112, video application 113, and terminal call manager 114 ). Hereinafter, the function of each component in the H.323 protocol stack will be described in detail.

Real-time Transport Protocol (RTP) 105 is a protocol for providing end-to-end real-time audio and video transmission services, and is defined in RFC 1889 by the IETF. RTP 105 provides transport protocol functionality with User Datagram Protocol (UDP) 103 beneath it. In addition, RTP 105 provides the functions of sequence numbering, timestamping, and delivery monitoring, and Real-time Transport Control Protocol (RTCP) 108 relates to RTP. Provide control services. G.711, G.729, and G.723.1 106 provide real time audio services, while H.261 and H.263 107 provide real time video services.

The H.225 Registration, Admission, and Status (RAS) 109 (Registration, Admission, and Status) 109 registers and permits control between an endpoint, such as a user terminal or gateway, and a gatekeeper. Admission control, bandwidth change, etc. are performed. H.225 call signaling 110 establishes a connection between terminals. H.245 Control Signaling 111 is used to exchange control signals between terminals.

The audio application 112 and the video application 113 are user applications using the H.323 protocol. The terminal call manager 114 manages Calls in the user terminal. IP 102, UDP 103, and TCP 104 are protocols commonly used on the Internet.

2 is a diagram illustrating a topology of an entire network providing a VoIP service according to the prior art.

As shown in FIG. 2, the user terminals 201, 202, and 203 access the network through the network connection device 204, the network address translator 205, the IP router 206, and the like.

However, according to the related art, only the terminal 201 assigned the public IP address may use the VoIP service, and the terminals 202 and 203 assigned the private IP address may not use the VoIP service. That is, in the H.323 protocol, a packet transmitted to an H.323 gatekeeper or an H.323 gateway at the time of handshake for call setup is IP. Not only includes an IP header of the user terminal, but also includes an IP address of the user terminal in the H.323 packet. That is, in the protocol stack shown in FIG. 1, the IP address of the user terminal is not included only in the IP header of the IP layer 102 as a source IP address, but is also included in the packet of the H.323 layer 115 and transmitted. However, the network address translator and the IP router according to the prior art convert only the source IP address in the IP header into the public IP address and transmit the source IP address in the H.323 packet to the external network without any change. That is, according to the prior art, only the source IP address in the IP header is converted into a public IP address, and the source IP address included in the H.323 packet is transmitted to the external network without any change.

The packet received by the H.323 gatekeeper or the H.323 gateway from the user terminal at the time of call setup is the source IP address in the IP header of the received packet (which has been changed to the public IP address by the network address translator) and H. The source IP address in the 323 packet (which is the private IP address assigned to the user terminal) is different. Therefore, the H.323 gatekeeper or H.323 gateway cannot perform proper call setup, and thus the user terminal cannot use VoIP service.

In addition, the high-performance portable terminals and notebooks that support wireless LAN are widely used, and as the wireless Internet develops, users can freely access the wireless Internet anywhere and use VoIP services. It became more and more serious.

The present invention is to solve the above problems, by accessing the Internet by receiving a private IP address through a network connection device such as a network address translator and an IP sharer, and by using a VoIP service again by assigning a public IP address, It aims to provide VoIP services to users while minimizing the use of public IP addresses.

In addition, the present invention provides a VoIP service by using a user terminal connected to the Internet through a network address translator without making any changes to a conventional user terminal and a VoIP server (such as an H.323 gatekeeper and an H.323 gateway). The purpose is to be able to receive.

1 is a block diagram illustrating a protocol stack of the H.323 protocol.

2 is a diagram illustrating a topology of an entire network that provides VoIP services according to the prior art.

3 illustrates a topology of an entire network for providing VoIP services in accordance with the present invention.

4 is a timing diagram illustrating signal flow between a user terminal, an intelligent access device, and an H.323 gatekeeper according to the present invention.

5 is a block diagram showing an internal configuration of a network connection device according to the present invention;

<Explanation of symbols for the main parts of the drawings>

301, 302: desktop computer

303, 306: network connection device

304, 305: notebook computer

307: the Internet

308: VoIP server

309: gateway

310: telephone network

311: phone

501: internal network interface

502: IP address processing unit

503: external network interface

504: packet inspection unit

505: private IP address provider

506: public IP address provider

507: public IP address storage unit

In order to achieve the above object and to solve the problems of the prior art, the present invention provides a public IP address storing unit for storing at least one public IP address, an internal network interface unit for receiving a request from a user terminal, A packet inspecting unit for determining whether the request is a request for a service associated with H.323, and if the request from the user terminal is a request for a service associated with H.323, the user terminal provides the public IP address to the user terminal. It provides a network access device including a public IP address providing unit to set the public IP address to its own IP address. The network access device according to an embodiment of the present invention provides a private IP address to the user terminal in response to an IP address allocation request from the user terminal, so that the user terminal sets the private IP address as its own IP address. It further includes a private IP address providing unit.

According to another embodiment of the invention, receiving an IP address allocation request (IP address allocation request) from the user terminal, in response to the IP address allocation request (private IP address) to the user terminal Providing the user terminal with the private IP address as its own IP address, receiving a request for a service associated with H.323 from the user terminal, and responding to the request for the service. providing an address) to the user terminal so that the user terminal sets the public IP address to its own IP address. The providing of the public IP address to the user terminal in response to the request of the service may include retrieving a private IP address set as the IP address of the user terminal.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

3 is a block diagram illustrating a topology of an entire network for providing VoIP service according to the present invention.

In order for a user to use a VoIP service with a desktop computer 301 or 302 or a notebook computer 304 or 305, the user terminal must first be connected to a network access device 303 or 306 according to the present invention. do. The network connection devices 303 and 306 may be connected to the user terminals 301 and 302 by wire or may be wirelessly connected to the user terminals 304 and 305. The user terminal connected to the network connection devices 303 and 306 may be various terminals for using VoIP services, such as PDAs and Internet phone terminals, in addition to the illustrated desktop computers 301 and 302 and notebook computers 304 and 305. .

Network connection devices 303, 306 according to the present invention store one or more public IP addresses. When a communication packet is input from the user terminal, the network connection devices 303 and 306 check whether the input packet is a packet for requesting VoIP service. If the input packet is a packet for requesting VoIP service, the network access devices 303 and 306 assign a public IP address to the user terminal so that the user terminal can normally use the VoIP service. If the user terminal is assigned a public IP address, the user terminal communicates with the external network using the public IP address, and the VoIP server has a source IP address of the user terminal in the IP header and a source IP address of the user terminal in the H.323 packet. Since all are the same as the assigned public IP address, call setup is normally performed. The method of assigning a public IP address according to the present invention will be described in detail later with reference to FIG. 4.

The network connection devices 303 and 306 are connected to the VoIP server 308 via the Internet 307. VoIP server 308 provides VoIP services to the user terminal. The user connects to the VoIP server 308 using a program installed in the user terminal. Depending on the type of VoIP server, the user authentication procedure may or may not be performed. A user using the terminal 304 can use the VoIP server 308 with another user using the terminal 301 to perform voice communication.

Gateway 309 connects two dissimilar networks. For example, a gateway connects an H.323 network with a non-H.323 network. In FIG. 3, the gateway 309 connects the H.323 network and the switching circuit (SCN) 310. The gateway 309 converts protocols for call setup and release, different networks. Conversion of media formats between, and transmission of information between different networks, thereby connecting different networks. By connecting the H.323 network and the switching network (SCN) 310 using the gateway 309, the user terminal 301, 302, 304, 305 equipped with an Internet phone application program using the H.323 protocol is installed. A voice call can be made with a general landline phone 311 or a general mobile phone (not shown).

4 is a timing diagram illustrating a signal flow between a user terminal, an intelligent access device, and an H.323 gatekeeper according to the present invention.

The user terminal 401 that does not use a static IP address must first be assigned its IP address from the network connection device 402 in order to access the network. In step 411, the user terminal 401 requests the network connection device 402 to assign an IP address. The IP address assignment request and the IP address assignment of the network access device may be performed using a Dynamic Host Configuration Protocol (DHCP). In response to an IP address allocation request from the user terminal 401, the network connection device 402 assigns a private IP address to the user terminal in step 412. The assignment of the private IP address is performed by selecting an unassigned private IP address from the pool of private IP addresses managed by the network connection device 402 and providing it to the user terminal 401. The network connection device 402 stores the entire range of private IP addresses to be assigned by itself, and also stores the private IP addresses already assigned.

The user terminal 401 sets a private IP address allocated from the network connection device 402 as its own IP address. When the user terminal 401 uses another general Internet service, the user terminal 401 uses the private IP address. That is, when the user terminal 401 attempts to access a web site, the user terminal 401 accesses the web site using the assigned private IP address as its source IP address. At this time, the network access device 402 converts the private IP address included as the source IP address in the IP header of the packet received from the user terminal into a public IP address and transmits it to the web site of the external network. This is a function performed by the network address translator according to the prior art.

In step 413 the user terminal 401 requests the VoIP service. VoIP services are performed using the H.323 standard protocol. The network connection device 402 examines the packet received from the user terminal 401 and determines whether the packet is a packet requesting VoIP service. According to another embodiment of the present invention, the network access device stores the IP address of the VoIP service server, and whether the destination IP address of the packet received from the user terminal 401 matches the IP address of the stored VoIP service server. By determining whether or not, it is determined whether the packet received from the user terminal 401 is a packet requesting VoIP service.

According to an embodiment of the present invention, the subscriber authentication procedure is performed in response to the VoIP service request from the user terminal 401. In step 414, the network connection device 402 requests the subscriber's authentication from the H.323 gatekeeper 403, VoIP service server or authentication server. Subscriber authentication request may be performed using a user ID and password. In step 415, the H.323 gatekeeper 403 or the like performs user authentication. According to another embodiment of the present invention, the subscriber authentication procedure may not be performed.

In operation 416, the network access device 402 assigns a public IP address to the user terminal 401. The network access device 402 stores one or more public IP addresses, and selects the public IP addresses that are not assigned to other user terminals from the stored public IP addresses and provides them to the user terminal 401. The user terminal 401 sets a public IP address assigned by the network access device 402 as its own IP address. The network connection device 402 stores the entire public IP address which it can assign, and also stores the public IP address already assigned.

In step 417 the user terminal 401 uses the VoIP service. Since the user terminal 401 sets its own public IP address as its own IP address, when using a VoIP service, the source IP address in the IP header is also a public IP address, and the source IP address included in the H.323 packet is also Matches with a public IP address. The network access device 402 does not perform separate IP address translation because the IP address assigned to the user terminal 401 is a public IP address. VoIP service servers such as the H.323 gatekeeper 403 are appropriate VoIP services because both the source IP address in the IP header and the source IP address in the H.323 packet match each other with a public IP address in the packet from the user terminal 401. Can be provided.

According to an embodiment of the present invention, when the use of the VoIP service of the user terminal 401 is terminated, the public IP address of the user terminal 401 is recovered, and the private IP address is allocated again. According to another embodiment of the present invention, the public IP address assigned to the user terminal 401 is used when the end of network use or the power of the user terminal is terminated even if the use of the VoIP service of the user terminal 401 is terminated. Until the user terminal 401 continues to use, and after the network use of the user terminal 401 is terminated or the power of the user terminal 401 is terminated, the public IP address is returned. In this case, even if another user terminal requests the VoIP service, if no IP address is assigned, the public IP address of the user terminal not currently using the VoIP service is recovered and assigned to the user terminal requesting the VoIP service. If it is impossible to assign a public IP address, it transmits a wait signal to a user terminal requesting VoIP service.

5 is a block diagram showing an internal configuration of a network connection device according to the present invention.

The network access device 500 according to the present invention includes an internal network interface 501, an IP address processing unit 502, and an external network interface 503. The IP address processing unit 502 includes a packet inspecting unit 504, a private IP address providing unit 505, and a public IP address storage unit 507.

The internal network interface 501 is an interface unit for connecting a network connection device to a user terminal, and the external network interface 503 is an interface for connecting a network connection device to an external network. It is wealth.

The packet inspecting unit 504 checks whether the packet input from the user terminal is a packet requesting a service associated with H.323. According to an embodiment of the present invention, the packet inspecting unit 504 stores the IP address of the VoIP service server, and determines whether the destination IP address of the packet received from the user terminal matches the IP address of the stored VoIP service server. Thus, it is determined whether the packet received from the user terminal is a packet requesting VoIP service. This embodiment has the advantage of simple implementation. According to another exemplary embodiment of the present invention, the packet inspecting unit 504 inspects whether the received packet is an H.323 packet by examining the inside of the H.323 packet of the packet received from the user terminal. According to the present embodiment, since there is no need to store the IP address of the VoIP service server, there is an advantage of saving the storage space. As shown in FIG. 1, after analyzing the IP packet, the UDP or TCP packet is analyzed. After the H.323 packet must be analyzed again, the implementation is complicated and the load of the network access device 500 is increased.

The private IP address providing unit 505 provides a private IP address to the user terminal. Allocation of a private IP address to the user terminal can be performed using a protocol such as DHCP, BOOTP. The private IP address providing unit 505 manages a pool of private IP addresses, selects an unassigned private IP address from the pool of private IP addresses, and provides the same to the user terminal. The user terminal then sets the private IP address to its own IP address. The private IP address providing unit 505 stores the entirety of the private IP addresses that can be assigned by itself, and also stores the private IP addresses that have already been allocated.

The public IP address storage unit 507 stores one or more public IP addresses that can be assigned to the user terminal. A public IP address is an IP address obtained from a legitimate authority. The public IP address providing unit 506 selects a public IP address not assigned to another user terminal from among public IP addresses stored in the public IP address storage unit 507 and provides the user terminal. The user terminal sets the public IP address allocated from the public IP address providing unit 506 as its own IP address. The public IP address storage unit 507 stores an entire public IP address that can be assigned by the network connection device, and also stores an already assigned public IP address.

Although the embodiments of the present invention described above have been described in relation to VoIP services, the present invention is applicable to all kinds of services related to H.323 within the scope of the technical idea of the present invention.

Embodiments of the invention also include computer-readable media containing program instructions for performing various computer-implemented operations. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The medium or program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. The medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, or the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above-described embodiments, which can be variously modified and modified by those skilled in the art to which the present invention pertains. Modifications are possible. Accordingly, the spirit of the present invention should be understood only by the claims set forth below, and all equivalent or equivalent modifications thereof will belong to the scope of the present invention.

According to the present invention, a private IP address is allocated through a network access device such as a network address translator and an IP sharer to access the Internet, and when the VoIP service is used, the public IP address is allocated again to minimize the use of the public IP address. It can provide VoIP service to user.

In addition, according to the present invention, without using any changes to the conventional user terminal and VoIP server (H.323 gatekeeper, H.323 gateway, etc.), the user using the user terminal to access the Internet through the network address translator You can get VoIP service.

Claims (7)

In the network connection device, A public IP address storage unit for storing at least one public IP address; An internal network interface unit for receiving a request from a user terminal; A packet inspecting unit for determining whether the request from the user terminal is a request for a service associated with H.323; And In case the request from the user terminal is a request for a service associated with H.323, the public IP address providing unit for providing the public IP address to the user terminal so that the user terminal sets the public IP address to its own IP address. Network connection device comprising a. The private IP address providing unit of claim 1, wherein the private terminal provides a private IP address to the user terminal in response to an IP address allocation request from the user terminal, thereby allowing the user terminal to set the private IP address as its own IP address. Network connection device further comprises. The network connection device according to claim 1, wherein the packet inspection unit examines a packet including a request received from the user terminal to determine whether the packet is a packet using H.323. In the method for providing a network connection to a user terminal, Receiving an IP address allocation request from the user terminal; Providing a private IP address to the user terminal in response to the IP address allocation request, so that the user terminal sets the private IP address as its own IP address; Receiving a request for a service associated with H.323 from a user terminal; And Providing a public IP address to the user terminal in response to the request of the service so that the user terminal sets the public IP address as its own IP address; Network access providing method comprising a. The method of claim 4, wherein And providing a public IP address to the user terminal in response to the request of the service, retrieving a private IP address set to the user terminal as its own IP address. 6. The method of claim 5, further comprising providing a VoIP service based on H.323 to the user terminal. A computer-readable recording medium having recorded thereon a program for executing the method according to any one of claims 4 to 6.