TW201616844A - Network connection system for solving connection limitations of network address translation and method thereof - Google Patents

Abstract

The present invention discloses a network connection system for solving connection limitations of network address translation (NAT) and a method thereof. The system is constituted by a plurality of private domains and a public domain with a simple traversal of user datagram protocol over NAT (STUN) server, such that a peer-to-peer (P2P) connection can be performed between the private domains through the STUN server. Furthermore, even for two private domains which are unable to use P2P to establish a connection, it is allowable to establish the connection indirectly by using an adjacent third-party private domain that is in a direct P2P connection with network devices of the two private domains. Therefore, under a condition of saving hardware equipment cost, the present invention can establish a P2P-like connection that is the best alternative connection technology with the closest P2P connection efficiency.

Description

Network connection system and method for solving network address translator connection limitation

The present invention relates to a network connection system and a method for solving the connection restriction of a network address translation (NAT); more particularly, it relates to a network that can establish the closest point-to-point network. The network connection system and method for the best alternative connection technology of peer-to-peer (P2P) connection efficiency.

In the prior art, peer-to-peer (P2P) technology, which shares computer resources and services through direct exchange, has been widely used, and is used in various content delivery applications. For example, watching live streaming, video on demand, instant messaging, or allowing users to publish multimedia content they own, creating personal channels, etc., is a direct way to provide multiple network devices. Network connection technology to achieve the highest network transmission speed without the need for an additional server.

However, P2P still faces some problems in practical applications, mainly due to the rapid development of the Internet and the increase of Internet users, resulting in the current Internet Protocol (IP) address. Will not be used, in order to avoid the above situation, most people will be in the private domain Network address translation (NAT) is deployed at the boundary of the public domain to solve the problem of insufficient network address. The so-called NAT is an Internet standard defined in RFC 1631. The packet sent by the network device of the private domain performs IP address translation, so that multiple network devices in the private network domain can share a public domain IP address to connect to the Internet, that is, private When the private domain IP data packet sent by the domain arrives at the NAT, the NAT is responsible for converting the private domain IP address into the public domain IP address. When an externally sent packet arrives at the NAT device, the NAT searches for the saved by itself. The information in the mapping table converts the public domain IP address into a private domain IP address and forwards it to the corresponding network device in the private domain.

As far as the type of NAT is concerned, it can be roughly divided into a Full Cone NAT, a Restricted Cone NAT, a Port Restricted Cone NAT, and a Symmetric NAT. Four types. The characteristic of the fully conical NAT is that when the internal user end establishes a connection with its external user end, any external user end can communicate with the internal user end according to the NAT corresponding address/an nickname of the internal user end; The characteristic of the restricted cone NAT is that when the internal user terminal establishes a connection with its external user terminal, only the external address that is connected to the internal user terminal can be based on the corresponding address/an nickname of the internal user terminal and the internal address. The user end communicates; the characteristic of the restricted conical NAT is that when the internal user end establishes a connection with its external user end, only the external address/an nickname that establishes a connection with the internal user end can be based on the internal The NAT corresponding address/an nickname of the client communicates with the internal client; and the characteristic of the symmetric NAT is that the internal client sends it to different The application at the destination end is assigned a corresponding NAT corresponding address/apostrophe, and only the address/apostrophe of the corresponding destination can communicate with the assigned NAT corresponding address/apostrophe. Accordingly, it can be seen that the above four NAT types have different connection restrictions, and the Symmetric NAT is the most restrictive. In view of this, in a environment where a large number of internal clients use a private domain IP address (or virtual IP address), when a client located outside the NAT (ie, a public domain IP address) wants to be located inside the NAT, When the user terminal establishes a data transmission connection with the P2P network technology, the request message sent by the client located outside the NAT is blocked by the NAT, so that the user inside the NAT cannot know the request for connection establishment. Caused the connection to fail.

In order to solve the above problems effectively, the Simple Traversal of User Datagram Protocol through NAT (hereinafter referred to as STUN) and the Traversal Using Relay NAT (hereinafter referred to as TURN) Network protocols such as Interactive Connectivity Establishment (hereinafter referred to as ICE) have been proposed. First, in the case of STUN, the STUN network protocol described in the Request for Comments (RFC) 3489 proposes a method to enable the client located inside the NAT to know the address assigned by the NAT/ The nickname and NAT type, and by providing this information to the client located outside the NAT, the two parties can establish a connection. However, STUN cannot operate successfully in the symmetric NAT (symmetric NAT) mode. In the case of TURN, the TURN network protocol is to deploy a TURN server in the public domain, where the TURN server will assign an address/apostrophe to represent the user inside the NAT. End, and use a mapping table to record the location The internal address of the NAT is used to communicate with the address/an nickname of the external communication and the assigned address/nickname. After that, the data entering and leaving the NAT will be forwarded through the TURN server to achieve NAT penetration. Purpose, although TURN can be used for the penetration of symmetric NAT, TURN server will become a performance bottleneck because the data flow of all clients in NAT needs to pass the TURN server. For ICE, ICE The network protocol proposes a hybrid NAT penetration method to solve the problem by using the functions of STUN and TURN. When the user needs to establish a connection through NAT, the user will first collect the original. The candidate network address information is exchanged, and then the candidate network address information is exchanged with each other, and the user terminal performs a connection test on the candidate network address of the other party, and finally determines an optimal connection for data. transmission.

Based on the above network protocol, some NAT penetration methods are proposed to enable a client located outside the NAT to penetrate the NAT to establish a connection with a client located inside the NAT, for example, hole punching proposed by RFC 5128. The method is to first build a rendezvous server (Rendezvous Server) under the public domain, and all the clients under the NAT establish a control message connection with the server in advance. For example, when client A wants to establish a direct NAT connection with client B, client A will first send a request to establish a connection message to the rendezvous server, and the rendezvous server will receive the request to establish a connection. After the message, the rendezvous server will transmit the NAT corresponding address/apostrophe of the client B to the client A, and transmit the NAT corresponding address/apostrophe of the client A to the client B, when the client A receives When the address information of the client B is sent, the client A sends a test packet to the NAT corresponding address/apostrophe of the client B, and the test is sealed at this time. The packet will be blocked by the NAT of the client B, but at the same time, the NAT mapping table of the client A will be changed to allow the NAT corresponding address/an nickname of the client B to transmit the data to the client A, and then the client B also sends the test. The packet is given to the NAT corresponding address/an apostrophe of the client A. At this time, the NAT mapping table of the client B is changed, and the NAT corresponding address/an nickname of the client A is allowed to transmit the data to the client B. According to this, the two-way NAT penetration connection can be successfully established. Of course, although the hole punching method can solve part of the NAT penetration problem, the types of NAT in both sides are 埠 restricted cone NAT and symmetric. In the example of NAT, or the type of NAT of both parties being symmetric NAT, as described above, since the symmetric NAT assigns different NAT corresponding addresses/apostrophes according to different destinations, the punching method cannot be used. As a result, users can use the TURN server as an alternative to complete the connection, which inevitably increases the hardware and bandwidth cost, and the data transmission performance is limited.

Therefore, how to directly use P2P peer-to-peer Internet technology to directly connect to reduce the cost of hardware and bandwidth resources, and establish the best alternative connection method for P2P connection efficiency. Many Internet service providers are working hard to develop and pursue an important goal.

The problem to be solved by the present invention is to provide a solution to the network address translation (NAT) connection limitation and establish the closest peer-to-peer (P2P) connection efficiency. The best alternative connection technology for network connection systems and methods.

In order to solve the above system problem, the present invention discloses a solution for limiting the connection of a network address translation (NAT). The network connection system includes a Simple Traversal of User Datagram Protocol over NAT (STUN) server and a plurality of private domains, each of which is located in a public domain. The device includes a network device and a network address translator electrically connected to the network device, wherein the network address translator is electrically connected to the STUN server, so that the network device and the network The connection between the devices is directly established by the STUN server using the peer-to-peer Internet technology, or the STUN server is indirectly established through the network device of the third-party private domain to establish a peer-to-peer Internet connection. The mechanism, wherein the network device of the third-party private domain can directly establish a connection with the network device of the first-party private domain and the network device of the second-party private domain by using a peer-to-peer Internet technology.

In order to solve the above method problem, the present invention discloses a network connection method for solving the connection limitation of the NAT by using the foregoing system. The method follows the following steps: Step 1: Each network device is translated through a network address The Simple Traversal of User Datagram Protocol over NAT (STUN) server finds the respective public internet address; Step 2: Determine whether each network device and the network device can The STUN server directly establishes a connection using a peer-to-peer (P2P) technology. If so, data is transmitted between the network device and the network device. If not, the search is possible. a third party directly connected to the network device of the first party private domain and the network device of the second party private domain The network device of the private domain; Step 3: After the network device of the third-party private domain searches for success, the network device of the third-party private domain is used to indirectly establish the network of the first-party private domain through the STUN server. The P2P connection mechanism that is closest to the P2P connection benefit between the device and the network device of the second-party private domain, and performs data transmission.

Further, the STUN server disclosed in the present invention provides a public internet protocol address and a network address translator of each network device, so that each network address translator is High-restricted-type port Restricted Cone NAT, or restricted-constrained NAT (Constricted Cone) NAT, Full Cone NAT, where When the network address translator of the first-party private domain is a high-wire restricted type, the network address translator of the second-party private domain is a low-wire restricted type; in addition, the aforementioned peer-to-peer network In the network technology connection mechanism, the network device of the third-party private network domain is a network device adjacent to the network device of the first-party private network domain or the second-party private network domain.

The present invention is characterized in that the present invention can directly establish a connection between the private network domain and the network device in the private network domain by using the STUN server by using the peer-to-peer Internet technology, thereby improving network resources. In addition to the transmission speed, the two private domains and the private network domain devices that are directly connected by using peer-to-peer Internet technology are connected to the private network and the private domain. The network device directly establishes a network device of the third-party private domain of the P2P connection, indirectly establishing a connection manner, so that the network device of the first-party private domain and the network device of the second-party private domain Third party The network device of the private domain is the medium, thus establishing a P2P peer-to-peer Internet technology connection mechanism that is the best alternative connection technology to the P2P connection benefit; accordingly, the third-party private domain network The device plays the role of the TURN (Traversal Using Relay NAT) server, so that the user does not have to add additional hardware devices for the purpose of connection, which greatly saves the cost. The operation mode of the TURN (Traversal Using Relay NAT) server It is well known to those of ordinary skill in the field of network technology and will not be described here. Therefore, the user can establish a P2P connection and establish the closest P2P connection between a network camera, a network phone, a network disk drive, a network printer or a computer with a network interface. The best alternative to line efficiency is the P2P peer-to-peer Internet technology connection mechanism that replaces P2P connection technology.

A‧‧‧public domain

B‧‧‧Private domain

C‧‧‧Private domain

D‧‧‧Private domain

B1‧‧‧ network device

B2‧‧‧Network Address Translator

C1‧‧‧ network device

C2‧‧‧Network Address Translator

D1‧‧‧ network device

D2‧‧‧Network Address Translator

X‧‧‧STUN server

S1~S221‧‧‧Steps

1 is a schematic diagram of a network connection system for solving a connection limitation of a NAT according to the present invention; FIG. 2 is a schematic diagram of a network connection system for solving a connection limitation of a NAT according to the present invention (2) And FIG. 3 is a schematic flow chart of the network connection method for solving the connection limitation of the NAT according to the present invention.

First, referring to FIG. 1 , FIG. 1 is a schematic diagram of a P2P point-to-point internet technology system according to the present invention; as can be seen from FIG. 1 , the network connection system for solving the connection limitation of NAT according to the present invention is Mainly includes: a STUN server X, which is set in a public domain A; Several private domains, in the first figure, three private domain examples are illustrated, respectively, private domain B, private domain C, and private domain D; wherein, private domain B is used to describe the private domain. The B system includes a network device B1 and a network address translator B2 electrically connected to the network device B1. The network address translator B2 is electrically connected to the STUN server X. The private domain C includes a network device C1 and a network address translator C2. The private network D includes a network device D1 and a network address translator D2, and the STUN server X. The connection relationship is like private domain B, and is not described here; accordingly, the network address translator B2, the network address translator C2, and the network address translator D2 are respectively directed to the STUN server. X passes the test signal, so that the STUN server X provides the type of the public network protocol address of the network device B1, the network device C1, and the network device D1, and the network address translator thereof, respectively. The network device B1, the network device C1, and the network device D1 can be connected to each other through the STUN server X, regardless of The network address translator B2, the network address translator C2, and the network address translator D2 are under the condition of a high-line limit or a low-wire limit network address translator (NAT). The network device B1, the network device C1, and the network device D1 can directly establish a connection by using the STUN server X using point-to-point internet technology (P2P) to obtain the highest network transmission speed.

Continuing to refer to FIG. 2 and refer to FIG. 1 , FIG. 2 is a schematic diagram of a network connection system for solving the connection limitation of NAT according to the present invention. FIG. 2 is a schematic view of the present invention. The network connection system for resolving the connection limit of NAT, if the network address translator B2, the network address translator C2, and the network address translator D2 are considered to be high-connected or low-connected Restricted type Under the condition (in Figure 2, the network address translator B2 is a high-line restricted type of Port Restricted Cone NAT, and the network address translator D2 is a low-wire restricted type. Restricted Cone NAT or Full Cone NAT, it is possible that the network device B1 and the network location C1 can be P2P connected, the network location C1 and the network The location D1 can be connected to the P2P, and the network device B1 and the network device D1 cannot be directly connected. In order to allow the network device B1 and the network device D1 to establish connection and transmission data, The network device C1 that can be connected to the network device B1 of the private domain B and connected to the network device B1 can be used as a medium for indirectly connecting the network device D1 and the network device B1, so that the network The device C1 acts as a TURN (Traversal Using Relay NAT) server to form a peer-to-peer Internet technology (P2P) (as shown by the L line), so that the user does not have to add hardware for the purpose of connection. Equipment, significant cost savings.

The network device B1, the network device C1 and the network device D1 can be a network camera, a network phone, a network disk drive, a network printer or a computer with a network interface.

Finally, please refer to FIG. 3 and refer to FIG. 1 and FIG. 2 . FIG. 3 is a schematic flow chart of a network connection method for solving the connection limitation of NAT according to the present invention. FIG. 3 shows the present invention. The network connection method for resolving the connection limitation of the NAT follows the following steps: Step 1 (S1): Each network device searches for the respective public internet protocol address through the STUN server, and performs step 2 ( S2); Step 2 (S2): determine whether each network device can establish a P2P connection through the STUN server; if yes, proceed to step 21 (S21), each of the networks Data transmission can be performed between the device and the network device. If not, proceed to step 22 (S22) to find a direct connection with the network device of the first party private domain and the network device of the second party private domain. The network device of the third-party private domain of the line; Step 3: following the foregoing step 22 (S22), when the network device of the third-party private domain searches for success, the process proceeds to step 221 (S221), and the third-party private network is utilized. The network device of the domain indirectly establishes a P2P connection mechanism that is closest to the P2P connection benefit between the network device of the first party private domain and the network device of the second party private domain through the STUN server, and finally enters the step. 222 (S222), performing data transmission.

Therefore, the present invention can be used as a hardware device equipped with a network, and can use the present invention to establish a P2P connection and establish a P2P peer-to-peer Internet technology connection that is the best alternative to the P2P connection technology. The mechanism enables the two network devices that fail to establish a P2P connection to use the third-party network device as a medium to replace the TURN (Traversal Using Relay NAT) server, which saves hardware cost and can be quickly transmitted. The purpose of the information.

In the above, it is merely described that the present invention is an embodiment or an embodiment of the technical means for solving the problem, and is not intended to limit the scope of implementation of the present invention. That is, the equivalent changes and modifications made in accordance with the scope of the patent application of the present invention or the scope of the invention are covered by the scope of the invention.

B‧‧‧Private domain

B1‧‧‧ network device

B2‧‧‧Network Address Translator

C1‧‧‧ network device

C2‧‧‧Network Address Translator

D1‧‧‧ network device

D2‧‧‧Network Address Translator

Claims (14)

A network connection system for solving the connection restriction of a network address translation (NAT), comprising: a network address translator user data package protocol in a public domain a simple Traversal of User Datagram Protocol over NAT (STUN) server; and a plurality of private domains, each of the private domain includes a network device and a network address translator electrically connected to the network device. Each of the network address translators is electrically coupled to the STUN server, so that the network device and the network device utilize peer-to-peer technology (peer-to-peer) by the STUN server. , P2P) directly establishes a connection, or indirectly establishes a peer-to-peer Internet technology connection mechanism by using the STUN server through a network device of a third-party private domain, wherein the network device of the third-party private domain The connection between the network device of the first party private domain and the network device of the second party private domain may be directly established by using P2P. The network connection system for resolving the connection restriction of the network address translator according to claim 1, wherein the network device of the third-party private domain is used as a corresponding network address translator Transit NAT (Tursal Using Relay NAT, TURN) server. The network connection system for resolving the connection restriction of the network address translator according to claim 1, wherein the STUN server provides the public internet protocol address and network address translation of each network device. Type of device. The network connection system for resolving the connection restriction of the network address translator as claimed in claim 3, wherein each of the network address translators is a restricted cone type (Port) Restricted Cone) NAT, Full Cone NAT or Restricted Cone NAT type network address translator. The network connection system for solving the connection restriction of the network address translator according to claim 1, wherein the first-party private network or the second-party private network is in the point-to-point internet technology connection mechanism. The network address translator of the domain is a Port Restricted Cone NAT type with a high connection limit, or a Full Cone NAT or a restricted cone type with a low connection limit. (Restricted Cone) NAT type; if the network address translator of the first party private domain is a high-wire limit type, the network address translator of the second-party private domain is a low-line limit Type. The network connection system for solving the connection restriction of the network address translator according to claim 5, wherein the network device of the third-party private network is adjacent to the network connection mechanism of the point-to-point Internet technology A network device of a private domain of one party or a network device of a private domain of a second party. The network connection system for solving the connection limitation of the network address translator according to claim 1 or 2 or 3 or 4 or 5 or 6, wherein each of the network devices is a network camera and a network Telephone, a network drive, a network printer or a computer with a web interface. A network connection method for solving the connection restriction of a network address translation (NAT) is used to establish a connection between a plurality of private network domains, each of which includes a private network domain a network device and a network address translator electrically coupled to the network device, and the method follows the following steps: each of the network devices transmits a user data package through a network address translator The Simple Traversal of User Datagram Protocol over NAT (STUN) server finds the respective public internet address; determines whether the network device and the network device can use the point-to-point with the STUN server. Internet-based technology (peer-to-peer, P2P) directly establishes a connection, and if so, data transmission between the network device and the network device, and if not, searches for a private domain with the first party The network device of the network device and the private network of the second party directly establishes a network device of the third-party private domain connected to the third party; and after the network device of the third-party private domain searches for success, the third-party private domain is utilized. The network device indirectly establishes a P2P connection mechanism that is closest to the P2P connection benefit between the network device of the first party private domain and the network device of the second party private domain through the STUN server, and performs data transmission. . The network connection method for resolving the connection restriction of the network address translator according to claim 8, wherein the network device of the third-party private domain is used as a corresponding network address translator Transit NAT (Tursal Using Relay NAT, TURN) server. The network connection method for resolving the connection restriction of the network address translator as set forth in claim 9, wherein the STUN server provides a network address translator type of each of the network devices. The network connection method for resolving the connection limitation of the network address translator according to claim 10, wherein each of the network address translators is a Port Restricted Cone NAT, a complete cone Network address translator for Full Cone NAT or Restricted Cone NAT type. A network for addressing the connection limit of a network address translator as described in claim 11 The connection method, in the point-to-point internet technology connection mechanism, the network address translator of the first party private domain or the second party private domain is a limited conic type with high connection limit ( Port Restricted Cone) NAT type, or Full Cone NAT type or Restricted Cone NAT with low connection limit; if the first party private domain network address translation When the device is in the high-wire limit mode, the network address translator of the second-party private domain is a low-wire limit type. The network connection method for solving the connection limitation of the network address translator according to claim 12, wherein the network device of the third-party private network is adjacent to the network connection mechanism of the peer-to-peer network. A network device of a private domain of one party or a network device of a private domain of a second party. The network connection method for solving the connection limitation of the network address translator according to claim 8 or 9 or 10 or 11 or 12 or 13, wherein each of the network devices is a network camera and a network Telephone, a network drive, a network printer or a computer with a web interface.