JP3663151B2 - Data transfer method, data transfer system, and receiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a data transfer method, data transfer system, relates to a contact and the receiving device, in particular a fault occurs on the selected path, even until routing information is rewritten, from the transmission side to the reception side The present invention relates to a technique that enables data delivery, prevents data loss, and is effective in realizing fault-tolerant data transmission.
[0002]
[Prior art]
As shown in FIG. 14, in a data transfer method on a network using packet switching by an IP datagram such as the Internet 30, a route from a transmission device 10 to a reception device 20 is set to 1 by static routing or dynamic routing. And the data is delivered using the single route (R1).
In static routing, a route used for data transmission from the transmission device 10 to the reception device 20 is registered by the administrator directly in the routing information, and the once registered route is retained unless the administrator changes it.
In dynamic routing, routing information is exchanged using a routing protocol such as RIP (Routing Information Protocol) or OSPF (Open Shortest Path First), and a route is dynamically set.
However, the route used for data transmission from the transmission device 10 to the reception device 20 is a route due to the occurrence of a failure after one route having the minimum number of hops in RIP and one route having the minimum cost in OSPF are selected. If there is no change in information, the same route is always selected.
[0003]
[Problems to be solved by the invention]
As described above, in the conventional data transmission method, since one route on the Internet is used for data distribution, if a failure occurs on the route, the failure is avoided until the routing information is rewritten. In the meantime, redundant data transmission using another route was impossible.
That is, as shown in FIG. 15A, in the conventional data transmission method, the data of (a1 to a4) is transmitted from the transmission device 10 to the reception device 20 via a single route (R1) on the Internet. However, as shown in FIG. 15B, if a failure occurs on the single path R1 before the data of a4 reaches the reception device 20, the reception device 20 receives the data of a4. Can not do.
For example, when traffic such as HD video data of about 120 Mbps is transmitted through a single path, a packet loss occurs in the router, and the video is temporarily interrupted.
[0004]
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is until a failure occurs on a selected route and routing information is rewritten in a data transfer method. In the meantime, it is an object of the present invention to provide a technique capable of delivering data from the transmission side to the reception side, preventing data loss, and realizing fault-tolerant data transmission.
Another object of the present invention is to provide for realizing the data transfer method described above, the data transfer system, the contact and receiving apparatus.
The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
[0005]
[Means for Solving the Problems]
Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
That is, according to the present invention, when data is transferred from the transmission side to the reception side using a network using packet switching, the transmission data B is generated by adding the redundant data C to the original data A on the transmission side. Then, the transmission data B is divided into M pieces to generate divided data (b _{1 to} b _M ), and position information for specifying the position of each divided data in the transmission data B is generated. The divided data (b _{1 to} b _M ) are transferred to the reception side using N paths, and the position transferred from the transmission device via the N paths on the reception side is added. The division data (b _{1 to} b _M ) to which information is added is received, the transmission data B is restored from the division data (b _{1 to} b _M ) based on the position information, and the original data A is restored from the transmission data B It is characterized by doing.
[0007]
According to the above means, when data is transferred from the transmission side to the reception side using a network using packet switching, it is set manually or automatically between the transmission device and the reception device. Multiple routes are used.
Therefore, when a failure occurs in a part of the route, it becomes possible to perform redundant data transfer using another route.
Then, as the redundant data, by using the duplicate data of the original data A, part of the original data A, even if not arrive at the receiving apparatus, based on the redundant data, it is possible to restore the original data A It is possible to prevent data loss and realize fault-tolerant data transmission.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.
[Embodiment 1]
FIG. 1 is a diagram for explaining a data transfer method according to the first embodiment of the present invention. In the present embodiment, first, the transmission apparatus 10 generates redundant data C for the original data A, and combines the original data A and the redundant data C to generate transmission data B.
Next, the transmission data B is divided into (b _{1 to} b _M ) sub-data and transferred from the transmission device 10 to the reception device 20 using N paths.
In FIG. 1, the transmission data B is divided into eight sub-data (b1 to b8), and the divided data {b1, b5}, {b2, b6}, {b3, b7}, {b4, b8} The case where it transfers to the receiver 20 using four paths | routes (R1, R2, R3, R4) respectively is shown in figure.
[0009]
As a method for setting the four routes (R1, R2, R3, R4), as shown in FIG. 2, in the transmission device 10 and the reception device 20, different network interface units (NIUs; hereinafter simply referred to as “network interface units”). , NIU) 51, and connected to another network via another router 52.
Alternatively, as shown in FIG. 3, one NIU 51 is connected to a plurality of routes through connections with a plurality (four in this case) of proxy servers (Proxy Servers) 53 existing on another network. Also good.
Further, the configuration of the transmission device 10 is the configuration shown in FIG. 2 (or FIG. 3), the configuration of the reception device 20 is the configuration shown in FIG. 3 (or FIG. 2), etc. You may set with the combination of the structure shown in 3. FIG.
[0010]
In addition, in the transmission apparatus 10, the position information of each divided data (b1 to b8) in the transmission data B as shown in FIG. 4 is added to the divided data (b1 to b8), so that the receiving apparatus 20 is divided. Even if the data (b1 to b8) arrive in an irregular order via different paths, the receiving device 20 again converts the divided data (b1 to b8) based on the position information shown in FIG. The transmission data B can be restored in order.
For example, information on whether the divided data is part of the original data A or part of the redundant data C as the payload type, and what number of the divided data of the original data A or the redundant data C as the sequence number And a source ID for uniquely identifying the affiliation of the data.
In the receiving device 20, the original data A is restored from the transmission data B based on the position information as shown in FIG.
[0011]
[Embodiment 2]
FIG. 5 is a diagram for explaining the data transfer method according to the second embodiment of the present invention. As shown in FIG. 5, the present embodiment is characterized in that x (x ≧ 1) duplicate data A ′ of original data A is used as redundant data C.
Note that FIG. 5 illustrates the case where the duplicate data A ′ of one original data A is used as the redundant data C, but in this case, the divided data {b1, b5}, {b2, b6}, {B3, b7} and {b4, b8} are the same data.
In FIG. 5, each divided data (b1 to b8) is transferred to the receiving device 20 using four paths (R1, R2, R3, R4).
In this case, if a trouble occurs on the route R1, as shown in FIGS. 6 and 7, a part of the data (the divided data b8 in FIG. 6, the divided data b1 in FIG. 7) is lost. There are cases where this happens.
However, in this embodiment, as shown in FIG. 6, when the divided data (b8) that is a part of the replicated data A ′ is lost, the divided data (b4) corresponding to the original data A is used as it is. The original data A can be restored.
As shown in FIG. 7, when the divided data (b1) that is a part of the original data A is lost, the divided data (b5) corresponding to the lost original data A in the duplicated data A ′ is used. Thus, the original data A can be restored.
[0012]
[Embodiment 3]
FIG. 8 is a diagram for explaining the data transfer method according to the third embodiment of the present invention. As shown in FIG. 8, the present embodiment is characterized in that error correction data P is used as redundant data C.
In FIG. 8, from the data that becomes {b1, b4}, {b2, b5}, and {b3, b6}, for example, data that becomes b7, b8, and b9 are generated by the parity method.
Here, b7 = b1 XOR (exclusive OR circuit) b4, b8 = b2 XOR b5, b9 = b3 XOR b6.
In FIG. 8, each divided data (b1 to b9) is transferred to the receiving device 20 using three paths (R1, R2, and R3).
In this case, if trouble occurs on the route R1, as shown in FIGS. 9 and 10, a part of the data (the divided data b8 in FIG. 9, the divided data b1 in FIG. 10) is lost. There are cases where this happens.
[0013]
However, as shown in FIG. 9, when the divided data (b8) that is a part of the error correction data P is lost, the divided data (b2, b5) corresponding to the original data A is used as it is. Can be restored.
Also, as shown in FIG. 10, when the divided data (b1) that is a part of the original data A is lost, the divided data (b4) that is a part of the original data A and a part of the error correction data P The lost divided data (b1) can be reproduced using the divided data (b7), and the original data A can be restored.
In the case of FIG. 10, the divided data of b1 can be reproduced by (b1 = b7 XOR b4).
As an error correction method, a hamming code generation or the like can be used in addition to the parity method.
Furthermore, in the present embodiment, the receiving device 20 can also detect and correct errors in the received divided data (b1 to b8) based on the received error correction data P.
[0014]
[Embodiment 4]
In the data transfer method according to the fourth embodiment of the present invention, when the divided data (b _{1 to} b _M ) is transferred from the transmission device 10 to the reception device 20 using N paths (R1 to RN). , M (1 ≦ m ≦ M), the route Rn (1 ≦ n ≦ N) used by the m-th divided data bm is automatically selected using the formula n = f (m) that is a function of m. It is a feature.
For example, if n = f (m) = m% N (where n represents the remainder when m is divided by N) as a function of m, as shown in FIG. The data (b1, b5) is transferred to the receiving device 20 after the route R1 is automatically selected.
Similarly, the R2 path is automatically selected for the divided data (b2, b6), the R3 path is selected for the divided data (b3, b7), and the R4 path is selected for the divided data (b4, b8).
[0015]
[Embodiment 5]
In the data transfer method according to the fifth embodiment of the present invention, when the divided data (b _{1 to} b _M ) is transferred from the transmitting device 10 to the receiving device 20 using N paths (R1 to RN). The ratio of the component of the original data A transferred using each path and the component of the redundant data C (replicated data A ′ or error correction data P) is averaged over time. The division data (b _{1 to} b _M ) are transferred to each of the N routes (R1 to RN) without being fixed to a specific route.
For example, in the case of FIG. 5, the redundant data C is transferred by transferring the component of the redundant data C (replicated data A ′ or error correction data P) once every two times on each path (R1 to R4). Are transferred to each path in an average manner.
Similarly, in FIG. 8, by transferring the component of redundant data C (replicated data A ′ or error correction data P) once every three times on each path (R1 to R3), the redundant data C The components are transferred in an average distributed manner in each path.
[0016]
[Embodiment 6]
Data transfer method according to the fifth embodiment of the present invention, a transmitting device 10, and generates the divided data by dividing the original data A to M _(a 1 ~a _M), the divided data _(a 1 ~a _M ) Is transferred to the receiving apparatus 20 by broadcast or multicast using L paths.
FIG. 11 is a diagram for explaining an example of the data transfer method according to the fifth embodiment of the present invention.
In the example shown in FIG. 11, the divided data (a1 to a4) obtained by dividing the original data A into four parts are transferred to the receiving device 20 by multicast using the four paths (R1 to R4). .
In this case, as shown in FIG. 12, even if the divided data a1 on the route R2 and the divided data a4 on the route (R2 to R4) disappear, (R1, Since the divided data of a1 is similarly transferred to the receiving device 20 via the route of R1, the divided data of a1 is transferred to the receiving device 20 via the route of R3, R4). Can be restored.
As described above, according to the present embodiment, if divided data (a _{1 to} a _M ) is transferred from at least one of the plurality of routes to the receiving device 20, it is used. Thus, the receiving device 20 can restore the original data A.
[0017]
[Embodiment 7]
FIG. 13 is a block diagram showing a schematic configuration of a data transfer system for realizing the data transfer method of each of the embodiments described above.
Hereinafter, a schematic configuration of a data transfer system for realizing the data transfer method of each of the above-described embodiments will be described.
As illustrated in FIG. 13, the transmission device 10 includes a data storage unit 11, a redundant data creation processing unit 12, a data division processing unit 13, a data output path determination unit 14, and a network interface unit 15. The
The data storage unit 11 stores original data A, redundant data C (replicated data A ′ or error correction data P), or transmission data B.
The redundant data creation processing unit 12 executes processing for generating redundant data C from the original data A stored in the data storage unit 11 and storing it in the data storage unit 11.
For example, in the above-described second embodiment, the redundant data creation processing unit 12 generates x (x ≧ 1) duplicate data A ′ of the original data A, stores it in the data storage unit 11, and In the third embodiment, the redundant data creation processing unit 12 performs a process of generating the error correction data P and storing it in the data storage unit 11.
[0018]
The data division processing unit 13 generates transmission data B from the original data A described in the data storage unit 11 and redundant data C (replicated data A ′ or error correction data P), and the transmission data B Is divided into M pieces to generate divided data (b _{1 to} b _M ).
As described above, when the transmission data B is divided, position information that can specify the position of each divided data in the transmission data B is generated and added to each divided data (b _{1 to} b _M ).
The data output path determination unit 14 determines which of the N paths (R1 to RN) is used to transfer each of the divided data (b _{1 to} b _M ) to the reception device 20.
[0019]
For example, in the case of the above-described fourth embodiment, the output path is distributed so that the mth divided data bm uses the n = f (m) th path Rn.
In the case of the above-described fifth embodiment, whether the divided data (b _{1 to} b _M ) is a part of the original data A, a part of the redundant data C, or both are included. Checking is performed, and the output path is determined so that the ratio of the original data A component and the redundant data C component in the data transferred from each path is temporally averaged.
The network interface unit 15 has one or a plurality of NIUs, and is connected to a network using packet switching via the NIUs.
When there are a plurality of NIUs, each NIU becomes an exit of the divided data (b _{1 to} b _M ) to one or a plurality of paths.
When there is only one NIU, the NIU becomes a single exit on the transmission device side to a plurality of paths, and the divided data (b _{1 to} b _M ) passes through a plurality of proxy servers 53 on another path. , Going out to multiple routes.
[0020]
The receiving device 20 includes a network interface unit 24, a data storage unit 21, a data composition processing unit 23, and a data restoration processing unit 22.
The network interface unit 24 has one or a plurality of NIUs, and is connected to a network using packet switching via the NIUs. When there are a plurality of NIUs, each NIU serves as an entrance of divided data (b _{1 to} b _M ) from one or a plurality of paths.
When there is only one NIU, the NIU becomes a single entrance on the receiving device side from the plurality of paths, and the divided data (b ₁ to b) from the plurality of paths via the plurality of proxy servers 53 on another path. b _M ) is input.
The data storage unit 21 stores the received divided data (b _{1 to} b _M ) or the restored transmission data B and original data A via the network 30.
[0021]
Data synthesis processing unit 23, from the received divided data _(b 1 ~b _M), based on the position information of the divided data added by the transmission apparatus 10 _(b 1 ~b _M), the process of restoring the transmission data B Execute.
The data restoration processing unit 22 performs a process of restoring the original data A from the transmission data B stored in the data storage unit 21 and storing the original data A in the data storage unit 21.
When the original data A is restored, if a part of the original data A in the divided data (b _{1 to} b _M ) is lost, that is, has not reached the receiving device 20, Based on the redundant data C (that is, the duplicate data A ′ or the error correction data P), the lost part is restored, and the original data A is restored.
Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course.
[0022]
【The invention's effect】
The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.
(1) According to the present invention, even when a failure occurs on the selected route and the routing information is rewritten, data can be delivered from the transmission side to the reception side, and data loss can be prevented. Fault tolerant data transmission can be realized.
(2) According to the present invention, when a failure occurs on a part of a route, the problem of being directly affected by the failure is improved, and the reliability is improved as compared with the conventional data transmission of only one route. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a data transfer method according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an example of a method for setting a plurality of paths in the data transfer method according to the first embodiment of the present invention.
FIG. 3 is a diagram showing another example of a method for setting a plurality of paths in the data transfer method according to the first embodiment of the present invention.
FIG. 4 is a diagram showing an example of position information added to divided data in the data transfer method according to the first embodiment of the present invention.
FIG. 5 is a diagram for explaining a data transfer method according to a second embodiment of the present invention.
FIG. 6 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the second embodiment of the present invention;
FIG. 7 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the second embodiment of the present invention;
FIG. 8 is a diagram for explaining a data transfer method according to a third embodiment of the present invention.
FIG. 9 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the third embodiment of the present invention.
FIG. 10 is a diagram for explaining that original data A can be restored even when a failure occurs on one path in the data transfer method according to the third embodiment of the present invention.
FIG. 11 is a diagram for explaining an example of a data transfer method according to a fifth embodiment of the present invention.
FIG. 12 is a diagram for explaining that original data A can be restored even when a failure occurs on three paths in the data transfer method according to the fifth embodiment of the present invention;
FIG. 13 is a block diagram showing a schematic configuration of a data transfer system for realizing a data transfer method according to each embodiment of the present invention.
FIG. 14 is a diagram for explaining a conventional data transfer method on a network using packet switching by an IP datagram such as the Internet.
FIG. 15 is a diagram for explaining a problem in a conventional data transmission method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Transmission apparatus, 11, 21 ... Data storage part, 12 ... Redundant data creation process part, 13 ... Data division | segmentation process part, 14 ... Data output path determination part, 15, 24 ... Network interface part, 20 ... Reception apparatus, DESCRIPTION OF SYMBOLS 22 ... Data restoration process part, 23 ... Data composition process part, 30 ... Internet, 51 ... Network interface unit (NIU), 52 ... Router, 53 ... Proxy server, A ... Original data, B ... Transmission data, a1-a4 , B1 to b9... Divided data, R1 to R4.

Claims (7)

Use a network with packet switching ,
The transmitting device adds the redundant data C to the original data A to generate transmission data B, divides the transmission data B into M (M> 1) pieces, and generates divided data (b _{1 to} b _M ). Then, position information for specifying the position of each divided data in the transmission data B is generated, the position information is added to each divided data, and the divided data (b _{1 to} b _M ) are set to N (N> 1). Transfer to the receiving device using
The receiving apparatus, is transferred from the transmission device via the N paths, receives divided data to which the location information is added (b 1 _{~b M),} based on the position information, the divided data A data transfer method for restoring the transmission data B from (b _{1 to} b _M ) and restoring the original data A from the transmission data B ,
The transmission device generates the transmission data B using x (x ≧ 1) pieces of duplicate data A ′ of the original data A as redundant data C,
The receiving device uses duplicate data of the lost data in the redundant data C when a part of the original data A in the received divided data (b _{1 to} b _M ) is lost. A data transfer method comprising restoring original data A. The transmission device transfers the division data (b _{1 to} b _M ) to the reception device using N paths (R 1 to RN), and the m (1 ≦ m ≦ M) -th division 2. The data transfer method according to claim 1, wherein a route Rn (1 ≦ n ≦ N) used by the data bm is determined using an equation n = f (m) that is a function of m. The transmission apparatus performs the transmission for each of the N paths so that the ratio of the component of the original data A and the component of the redundant data C transferred using each path is averaged over time. Te, the data transfer method according to claim 1 or claim 2, characterized in that to transfer the divided data (b 1 _{~b M).} A transmitting device and a receiving device are connected via a network using packet switching ;
The transmission apparatus includes transmission data generation means for generating transmission data B by adding redundant data C to original data A;
The transmission data B is divided into M (M> 1) to generate divided data (b _{1 to} b _M ), and divided data for generating position information for specifying the position of each divided data in the transmission data B Generating means;
Transfer means for adding the position information to each of the divided data and transferring the divided data (b _{1 to} b _M ) to the receiving device using N (N> 1) paths,
The receiving device receives the divided data (b _{1 to} b _M ) to which the position information is added, transferred from the transmitting device via N paths;
Data combining means for restoring the transmission data B from the divided data (b _{1 to} b _M ) based on the position information, and original data restoration means for restoring the original data A based on the transmission data B A data transfer system comprising:
The transmission data generation means of the transmission device generates the transmission data B using x (x ≧ 1) pieces of duplicate data A ′ of the original data A as the redundant data C ,
The original data restoring means of the receiving device copies the lost data in the redundant data C when a part of the original data A in the received divided data (b _{1 to} b _M ) is lost. A data transfer system which restores original data A using data. The transfer unit of the transmission device transmits m (1 ≦ m ≦ M) when transferring the divided data (b _{1 to} b _M ) to the reception device using N paths (R1 to RN). 5. The data transfer system according to claim 4, wherein a path Rn (1 ≦ n ≦ N) used by the n-th divided data bm is determined using an equation n = f (m) that is a function of m. . The transfer means of the transmission apparatus is configured to transfer the N paths so that the ratio of the component of the original data A and the component of the redundant data C transferred using each path is temporally averaged. The data transfer system according to claim 4 or 5 , wherein the divided data (b _{1 to} b _M ) are transferred to each of them. A receiving device used in a data transfer system in which a transmitting device and a receiving device are connected via a network using packet switching,
The transmission data B is divided data divided by M (M> 1), and position information specifying the position of each divided data in the transmission data B before division is added, and N (N> 1) pieces of data are added. Receiving means for receiving the divided data (b _{1 to} b _M ) transferred from the transmitting device via a path;
Data combining means for restoring the transmission data B from the divided data (b _{1 to} b _M ) based on the position information;
Original data restoring means for restoring the original data A from the transmission data B ,
The original data restoring means, when a part of the original data A in the received divided data (b _{1 to} b _M ) is lost , the original data restoring means in the received divided data (b _{1 to} b _M ) A receiving apparatus which restores original data A using duplicate data of lost data .

Images