JPS58153442A - Data communication system - Google Patents

Abstract

PURPOSE:To attain communication between buses with a simple configuration, by connecting a repeater between a pair of buses to discriminate whether a bus address is the one to transmit through the pair of the buses or not and repeat only the data to be transmitted through the pair. CONSTITUTION:A station 23A transmits/receives signals to/from a bus 22A through an interface 24A and a transceiver 25A. A repeater 30 is connected between two buses, and in the figure it is connected between the buses 22A, 22B. In addition to a station address, a bus address is added to the address of data generated from the station 23A as a designation address and an originating address, so that the interface 32 (32A, 32B) of the repeater 30 enters data and transfers them to the opposite bus only when the data are the opposite bus address.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a data communication system having a plurality of communication media and in which communication is performed via the communication media.

[Technical background of the invention]

One of this type of data communication system is the US X@rox
Corporation rKth*rnstJ (
Hereinafter, there is a system known simply as "1cth@r!l・t".This system is described in H%IGLil [1-114804 publication.The specifications of Eth@r+a@t mentioned above are described. For US X@rox Corpora-1iB, Digital
rTheEth@vn@t Published by l Kqulpm@nt Corporation and Int@l Corporation 17c;
ocal ar@a n@work , Dat
/1ink lay@r and physical
lay@r ap@emu f1cationsJ (198
(Published on September 30, 2013), the explanation will be omitted here. The technology for forming a local network by providing a plurality of such Eth@rn@t and connecting two or more 10 Ktk@rm@t j4 is [
Ith@r+ attracting attention as a cl-cal network
a@t ; Television Journal, Vol. 34 @ No. 5 (198
0 year) pages 389-395J [described in J.

Figure 1 shows the configuration of a conventional data communication system to which the above technology is applied.
h@rn@%2 is an f-)way computer (hereinafter referred to as GW computer). In general, a GW computer uses two or more Eth@r and two or more Et
It has an h@rn@t interface circuit (hereinafter simply referred to as an interface), which itself has a unique station address (this is particularly referred to as a GW address). In FIG. 1, the Gw computer 2 has three Eth@rn
@t Three interfaces 2m+21yJC are set up to connect between 11 and 1c.

I'm being kicked. GW computer 2 is connected to Eth*rn@t1 via ink 7 ace 2 and transceiver 3, and also has interface 2 recommended and transceiver 3. t- connected to Eth@rn@t IB via
Similarly, it is connected to 1cth@rn@tIc via <interface 2CN)7 receiver 3c. On the other hand, station 4
Eth*rn@t JA through the corresponding interface 5m~5c and transceiver 6m~6c
- connected to lc. 7m~7c are each ICt
This is a cable forming h@rn@t1~1c. Cables 7m to 7c are coaxial cables.

In the system shown in FIG. 1, when transmitting information from station 4 to station 4c, A
Create a file and send it to Eth@rn@t7.

The address part of this z4 packet contains the Eth@rn@t1 module to which the station 4c that is the originator of the packet belongs (the 1 address when the station 4c that is connected and sends the above packet to the desired station 4c)
The GW address of the GW computer 2 that will become the next relay station is written. Similarly, the source station address of the arm socket is written in the address field of the mother socket. In addition, the address of Ethsrn@t1c to which the final destination station belongs (final station Ethe
rm@t address) and the final transmission destination station address (final station address) are written in a predetermined area of the data section (variable length). Similarly, in the predetermined area of the data section of the notebook, Eth@rn*t to which the originating station belongs
JA address (source Ethernet address)
and the above source station address are written.

/4 sent from station 4 to ICthern@t JA
The packets are commonly transferred via transceivers to each interface connected to the Eth@rnet 1 system. Therefore, in the interface 2, the GW address in the address section of the above No.
Identify whether or not an address matches.

If they match, the GW computer 2 takes in the above /# digits. And GW calculator 2 is the above fkerato.

The final station written under the data Eth@rn・t
A relay route is determined by referring to an address table for determining a transmission route according to the address. Here, address chisol will be explained. In the above example, the Eth/rnet IC that is the relay destination of the GW computer 2 and the final station Eth@r
n@t is rounded to match, and the GW computer 2 can determine the relay destination based on the final station Eth@rn@t address among the above 9 digits.

However, data communication systems typically have a large number of Eth*r
When transmitting data to a station consisting of stations consisting of n@t, using the conventional method, No. 9 is required.

is the first (D gth・rn@t→
1st GW computer - + $ 2 Eth@rn@t - + 2nd GW computer → ... → GW computer of agn → Many GW computers, many Et like the final station Eth@rn@t
Generally, h・rn@t is red and white and sent to the final station. If the configuration of Eth@rn@ in the system is fixed, if the final station gth, rn, t is specified, the Eth@rn@t to be relayed, and furthermore, the next GW computer (i.e., the relay route) can all be specified. It is possible. The above address table shows that this relay route is registered corresponding to the final station Eth@rn@t address.

When the GW computer takes in /4', it refers to the address table according to the final station Eth@rnet address written in the data section. The address of Eth@rn@t to be relayed and the GW address of the next GW computer if this Ethernet is not the final station Eth@rn@t are registered in this address table.

The GW computer writes the GW address obtained from the address table to the first half src of the address section shown in the format of FIG. 2 in the notebook, and writes its own GW address to the second half of the address section. In addition, the relay spell Ith@rn・t is the final station Ether
net, the GW computer writes the final station Ethsrn@t address and the final station address written in the data section of the packet to the first half of the address section. In the latter half of the address field, the own GW address is written as in the case described above.

In this way, in conventional data communication systems, two or more E
By connecting the Ethernets by the GW computer, a large number of Ethernets (communication media, networks) are organically connected, and data communication between arbitrary stations is performed.

[Problems with background technology]

In such conventional data communication systems, ■ Eth
When the configuration of @rn@ is changed, the address table in the GW computer must be updated separately for each GW computer.

■ Since the GW computer itself has a station address, the originating station must know the station address (GW address) of the GW computer to be relayed, and must specify this station address in the address part of the quantity.

■ When the GW computer relays packets, it is necessary to refer to the address table in order to know the relay destination.

(2) When the GW computer relays the host packet, it is necessary to reorganize the packets based on the result of referring to the address table.

■ Since there is an extremely large amount of content to be processed by the GW computer, the amount of communication that the GW computer can process is limited to Eth@rn.
The amount of communication allowed on @t (coaxial cable) is significantly lower. For this reason, if there is a large amount of communication via the GW computer, a situation will occur where communication cannot be performed on the 1cth@rn@ to which the transmitting station or receiving station is connected, even if there is enough traffic above. , if it cannot be processed by one GW computer,
Requires multiple GW computers 0 ■ Relay Eth @
Since the hardware amount of the GW computer differs depending on the number of rn and t, it is difficult to standardize the GW computer. And G
In order to standardize W computers, relay Kth@r
It is wasteful to have to match the maximum number of +a@t.

Moreover, even with this arrangement, address tables must be prepared separately for each GW computer.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to:
It is an object of the present invention to provide a data communication system in which system reorganization due to changes in the configuration of communication media can be carried out extremely easily.

Another object of the present invention is to provide a data communication system that can simplify the configuration of devices and stations that connect communication media.

Still another object of the present invention is to provide a data communication system in which the hardware and software configurations of devices for T-connection between communication media can be made common, and the amount of communication that can be processed can be increased.

[Summary of the invention]

Between a pair of overconfident media t! ! an address setting unit for setting a unique communication system address for each pair of communication media connected to the self-relay device within the relay device; , the communication system address in the destination address section of the /f packet on one of the pair of communication media connected to the self-relay device is set in the address setting section on the other one of the pair of communication media. an interface mechanism that determines whether or not the address matches the communication system address of the communication medium of the above communication medium, receives the corresponding 74 digits when they match, and sends the corresponding 74 addresses to the other communication medium; By doing so, data communication can be performed on the station side without being aware of the existence of the relay device, simply by being aware of the communication system address of the destination station and the communication medium to which the destination station is connected. It was designed so that

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In the data communication system of FIG. 3, 21A, 21. is a communication medium, for example Ethernet.

221.22m is gth*rnet2J1. ?
Cable forming J1, 23mm + ZJ11 +23
N Goose is the bureau. Station 23 is connected to ICtharn*t 21 via interface 24 and transceiver 25. Stations 23B1 +23mx each have an interface 24B1 r24sms24m CNO t25. ,．． Ethernet21 via 25 Agriculture 3
connected to m.

30 is a relay device. The relay device 30 is the relay device main body 3
1, an interface 32, an address setting switch 33, and an address setting switch 33. The relay device main body 31' includes a CPU having a data relay processing function and a memory (both not shown) for temporarily storing data (buckets). Interface 32A, 32. are used to connect each one of the pair of Ethernets to the relay device main body 31. In this example, the relay device main body 31 is connected to the Gthern@t21 module via the interface 32 and the transceiver 411, and is also connected to the Ethernet 2 node via the transceiver 411 via the interface 32. The interfaces 32 and 32 respectively monitor the address part of the 9th box above the corresponding ICth@rn@, and send the Ether indicated in the destination address.
Kth@r whose n@t address is predetermined
It has a function of detecting whether or not it matches the n@t address. Then, the interfaces 32 and 321 take in the corresponding notebook in accordance with the above detection result. The address setting switch 33 is connected to the interface 32.
gth.r, which is the destination of the message that the program should import.
This is a switch for setting the address (Eth/rust address) of nst (that is, Ethernet connected to the interface 32m). In addition, the address setting switch 33N+ sets the address setting switch 33N+ to Kth rn・t(
That is, the Ether connected to the interface 32
This is a switch for setting the address (Eth@rn@t address) of (Eth@rn@t address). In addition, address setting switch 33m.

33IIt- It is possible to make it common, add one new changeover switch, and use this changeover switch to change over the setting section. It is also possible to set the address using the keyboard.

FIG. 4 shows an example of an embodiment of the present invention, in which a destination address and a source address are written in the address section.

The destination address consists of the Ethernet address of gth@r+a・t to which the destination station (receiving station) is connected, and the address in the Eth@rnat (station address) that is the address of the destination station. . Source address = is the Ethernet address to which the originating station is connected.
It consists of the th@rnet address and the address of the originating station, that is, the Ethernet address (station address). The structure of this address section is basically the former shown in FIG.

The content is the same as the content of the predetermined area of the data section of the page. In other words, in this embodiment, the address field of the format F shown in FIG. 2 is completely disrespectful, and therefore, the contents of the predetermined area of the data field can be assigned to this address field, so the data field can be turned into a true data area. Can be used.

Next, the operation of one embodiment of the present invention will be explained. First, the Eth@rn@t address is set in advance by operating the address setting switch 33mr33m'.

In this example, the Ethernet connected to the interface 32 of the relay device 30, that is, the interface 32
．． The destination Eth@rn@t is Eth@rn
@t21, and Et with the address setting switch 33m.
b@rys@t 21 m's Eth@rn@t address x
'l Set.

Similarly, address setting switch 33. Ethern t
Set the Eth@rn@t address of 21m. In addition,
In addition to gthernet 21 A and 21 B, there is also E
ethernet, and a vertical device (similar to the relay device 30) that connects these Ethernets and each Ethernet@t on a one-to-one basis is installed, set the address setting switch of these relay devices. It is necessary to operate and set the corresponding ff1th*r+a@t address in advance as described above.

In this state, from station 23 connected to Ethernet J 1 m,
Station 23B connected to! The addressee is Eth
Suppose that it is sent on srmet jl A. Et
hernet J 1 m above no mother ke, t is Etll@'
It is transferred from the transceiver connected to rn@t 21 A to each interface 78 of the corresponding station or relay device. Interface 32 of relay device 30. is Ethern
Et of the 79-bit destination address on et 2 J h
The Kth@rn*t address portion (see FIG. 4) is monitored and a match/mismatch between this Kth@rn*t address portion and the 7jEth@rnet address set by the address setting switch 33 is detected. In this case, the above 7
In the Eth@rn@t address part of the 9-bit destination address,
The address has been written and the interface 32 detects a match. As a result, the interface 32 inputs the corresponding 9 bits into rg and outputs it to the relay device main body 31. The relay device main body 31 temporarily stores the packet output from the interface 32 in memory. The packet stored in the memory is output as is to the interface 32, and is sent to Eth.r*@L21 by the interface 32n.

The above is the operation of the relay device 30. As is clear, the relay device of this embodiment has a pair of Eth@rn@t21 and 21
Since the configuration connects only 18th@
If rn@ is used to identify the Ethernet destination of the packet above, and the corresponding packet is imported according to the identification result, it may be possible to transmit the packet without any processing without paying any attention to the sending route of the packet. without and/
It is only necessary to uniquely send the other Eth·rn@ upward without switching the destination of the message.

Ethe via the interface 321 of the relay device 30
Packets sent on rnet 21 m are sent on Eth
- Transferred from the transceivers connected to rn@t 21 H to the corresponding station interface. Then, the destination address of the mother packet is identified at these interfaces. In this case, 1 above 2 digits are station 23.
31, interface 241!
It is taken over by station 2311. As is clear from the format Y in FIG. 4, the /gukerato in this embodiment does not include address information other than the address information corresponding to the source and destination (such as the GW address in FIG. 2). No, station 2311 (interface ff14B1)
is the same]Ethernet 21 4C As in the case of importing packets transferred to the local station 2311 from other stations connected to the 4C (such as station 23■),
et 21, it is possible to take in the /track sent via the relay device 30. These operations are based on Eth
A station connected to ernet 21 B, for example station 23mz
The same is true when transmitting a host packet to a station connected to the Ethernet 214, for example, the station 23. In this case xth・rnet 21/? on the intestine? The decision as to whether or not to import the packet will be made by the interface 32. Then, when the above-mentioned Nodaket force I) is taken in by the interface 32, its sending destination is uniquely Ether*t21, that is, the interface on the side different from the interface 32m on the 9ket intake side. Ether connected to 32mm
It becomes net.

As is clear from the above description, according to this embodiment, numerous effects as listed below can be obtained.

■ Each station is not aware of the existence of the relay device (Eth@
You can use rn@ to perform communication between.

■ The ability to simplify the 9-station configuration can be achieved through (■) above.

■ The message was taken in by the relay device! Since the sending destination of () is uniquely determined by the pair of connected Ethernets, the judgment process for determining the sending destination route, the address table necessary for this judgment, and the
Caloe treatment, etc. (completely unnecessary.

■ Due to the above (■), the amount of communication that can be handled by the relay device increases significantly.

■ Similarly, according to ■ above, even if the configuration of the nine ICth@rn@ is changed, there is no need to change the configuration of the relay device; simply change the address setting switch to the newly connected Eth@ to the own relay device. Just set the rn@t address.

(2) Similarly, the relay device can be simplified due to (2) above. In addition, according to (1) and (2) above, the same hardware and software of the relay device can be used regardless of the combination of connected Ethsrn@ts, so the relay device can be used in common.

Next, another embodiment of the present invention will be described with reference to FIG. Figure 5 shows an N-story pilding (hereinafter referred to as a building) 50, three Eth@ru@t51 units, 51. ．． 5
1c is a system configuration diagram of a data communication system configured with a large-scale Eth@rn*. In the figure, 52
52B, 52c are each Ethernet571
, 51B, 51c trunk cable, pill 50
Each floor is laid out perpendicularly to the other. A pair of Eth@rn
*t 51 A and 511 are connected by a relay device 53 (similar to the relay device 30 shown in FIG. 3), and a pair of E
thsrnst 51 B, 51 (connected by a relay device 54, a pair of Eth@rn@t51c, 51
The two systems are connected by a relay device 55.

IF-NF is on the first floor of Pill 50~Np! It indicates ti o-
c'iru. IF~N-4F has trunk cable 52mm~5
Cable that is physically separated from 2c (Etb@r
n*t cable) 601 to 6ON-, are being installed. 9. For N-2F-NF, use the same cable 60N.
-, ~6ON are installed. In addition, 1 cth each is sent to N-3F without going through the relay devices 53 to 55't-.
Three cables 61m to 61c are laid so that communication can be performed using ern@t 51m to 51c. D...T is a transceiver, and R...R is a repeater. The repeater R is a device that electrically connects physically separated cables, and has the function of transmitting all electrical signals flowing through one cable to the other cable.

In this embodiment, the cables 601 to 601 installed in the IF-NF
60H-4 +611~61c, 60H-H~60H are Etb@rntht 5 r via the corresponding repeater
- 51c as shown in the figure.

62.63 is the station. Station 63 is a station installed on N-3F, and all Eth@rnst 51~51
It is connected to cables 61m to 61c so as to be connected to c. Note that stations other than stations 62 and 63 are not illustrated.

In the configuration shown in FIG. 5, the relay device 53 has gth@rn@t
51A and 5C are set, the relay device 54 is set with Ether@t 51B and 51C, and the relay device 55 is set with Eth@rnet.
It is necessary to set the -6 address of 51 (, 51A).These address settings can be done very easily using the address setting switch (address setting section) as described above.As is clear, the relay devices 53 to 51A The configurations of 55 differ only in the above-mentioned address setting contents, and the hardware configuration and software configuration are common.Therefore, as can be deduced from the previous example, in this example, Ith@
Even if the number of rn@t increases, standard relay equipment is still used,
By simply setting the address of the Ethsrnst connected to this relay device using an address setting switch, the above-mentioned increase can be dealt with extremely easily.

By the way, in a local network in a building or the like, there are cases where it is desired to leave the cables installed on each floor as they are and move only the equipment (stations) connected to the cables from floor to floor. In such a case, in this embodiment, it is sufficient to simply switch the transceiver to which the repeater R is connected, making it extremely easy to change the layout.

For example, when replacing each device on N-2F and each device on N-5F in Fig. 5, the corresponding cable 6
01i-2+ 6's-s through repeaters R and R1- as shown by the broken lines in the diagram
Just connect to @rnet 52C, 52B.

By doing so, the layout can be changed without affecting the logical configuration of the system.

In addition, in the configuration of FIG. 5, each Eth@rn@t51~
51c are connected to each other in a one-to-one correspondence by relay devices 53-54. Therefore, communication from any station to any station within the building 5° only needs to go through a maximum of two Ethernets, and other Ethernets are not affected. In the example of FIG. 5, it is preferable that floors with relatively large amounts of mutual communication be connected to each other so that they belong to the same Ethernet.

By the way, in the example in Figure 5, the trunk cable (Kth@rn@
t) is 3, but in the case of 4, the number of relay devices is up to 6 (relay device 70) as shown in the faG diagram.
M~70F) is required. In this case, it consists of Ether
If communication between ETs is not required, the number of relay devices may be less than six. Generally, if the number of Eth@rn@t is N, the number of relay devices required to connect all these Ethernets one-to-one is N(N-1)/2
becomes.

In the above embodiment, a data communication system configured with gth@rn@ has been described, but according to the gist of the present invention, carrier sensing multi-sol access (C8MA) or CS MA with collision detection (C8!vIA-CDJ) has been described. It can also be applied to a local broadcast communication medium using a channel access method called .

〔Effect of the invention〕

As described in detail above, according to the data communication system of the present invention, system reorganization due to changes in the configuration of communication media can be carried out extremely easily.

Further, according to the present invention, the configurations of devices and stations that perform T-connection between communication media can be simplified.

Further, according to the present invention, it is possible to standardize the hardware configuration and software configuration of the connection device, and the processing speed is increased by increasing the amount of communication that can be processed.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram showing a conventional example, Fig. 2 is a diagram showing a conventional Notacket format, Fig. 3 is a system configuration diagram showing an embodiment of the present invention, and Fig. 4 is applied to the above embodiment. Figure 5 is a system configuration diagram showing another embodiment of the present invention, and Figure 6 is a connection form with a relay device when there are four GTH and NNT (communication media). FIG. 1mu~1c, 21mu, 2111, 51mu~51c...
1cth@rn@t (communication medium), 2...Dartway computer (GW computer), 2h~2cr5h~5c+2
4mu, 24m1 e24Bg, 32mu, 32B-...
Interface (Ethern@t interface circuit), 4h to 4c *231 * 23B@e2BB,,
62.63...station, 30.53~55...70,~
70. ...Relay device, 33M, 33M...Address setting switch (address setting section). Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) In a data communication system that has a plurality of communication media and in which communication is performed via the communication media, a data communication system is provided for each pair of communication media among the plurality of communication media, and the corresponding communication medium is Each relay device includes a relay device connected via a transceiver, and this relay device includes an address setting unit that sets a unique communication system address for each of the corresponding communication media, and a relay device that sets a unique communication system address for each of the corresponding communication media, and a identify whether or not the communication system address in the destination address section of (Δ) and (g) is a communication system address specific to the other communication medium among the corresponding communication media set in the address setting section; A data communication system comprising: an interface mechanism that captures m packets and sends them to the other communication medium according to the identification result; (2) when the number of communication media is N; , the maximum number of said medium vertical devices connected to these communication media is N(N-1)/2, the data communication system according to claim 1.