JP2954679B2 - Adapter for data communication system and datagram type protocol conversion used for it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a different model or a different protocol connected to each other by a local area network (hereinafter referred to as "LAN") in which a physical layer address is uniquely determined. The present invention relates to a data communication system between various computers to be used and a protocol conversion adapter for realizing the data communication system.

In this specification, the term "computer" is not limited to a general-purpose large computer, but also includes office workstations, personal computers, various work stations, document creation / editing devices, graphic creation devices, intelligent copying machines, high-performance facsimile machines. It also includes various dedicated devices incorporating a computer such as a device and an internetwork router.

[Conventional technology]

In recent years, various high-performance and low-priced computers have spread,
LANs have come to be used on a daily basis for communication between these computers.

In addition, the number of cases where a plurality of different protocols are used in combination on the same LAN is increasing as the standardization of the LAN progresses. These protocols form a logically independent network (logical network), so that data communication between computers having different protocols cannot be performed as it is.

In order to perform communication between different protocols, protocol conversion is required, and there is a device called a gateway which performs the conversion.

As a norm that clearly defines the protocol, there is a protocol seven-layer model defined by ISO OSI. Various protocol systems are realized with reference to this.

In order to perform intercommunication, the protocols in each layer need to be the same, and the gateway performs protocol conversion for each layer even in a LAN where the physical layer address is uniquely determined (the same physical LAN) such as Ethernet. Is going.

[Problems to be solved by the invention]

However, since the gateway converts all of the complicated protocol systems, it takes a long processing time to realize high-speed data communication, and re-creating the gateway to cope with the emergence of a new protocol is a major task.

Therefore, the cost of gateways is generally high. In a network using a gateway, each computer on the network naturally needs to recognize the gateway used by the network.

Each of the computers must also recognize that the other party to communicate with uses a different protocol. Therefore, a special procedure for using the gateway is required for each computer on the network side.

In addition, when installing on a network, generally a complicated setting operation is required on the gateway side in order to correspond to the attributes of various protocols flowing through the network.

From the above points, there are many problems in introducing a gateway to realize high-speed data communication between computers of different models or different protocols on the same physical LAN.

The present invention has been made in view of such a situation, and solves the above-described problems, and allows various computers including those of different protocols connected by LAN to communicate with each other.
An object is to enable high-speed data communication easily.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a local area network (LA) in which a physical layer address is uniquely determined.
N) In a data communication method between various computers connected to each other by using different models or using different protocols, a datagram packet protocol conversion adapter is installed on the LAN, and all computers in the system are connected. The network layer and transport layer addresses of all the datagram-type protocols to be converted are virtually allocated to the physical layer addresses held, and the physical layer of each of the above computers is converted by the protocol conversion adapter. The addresses and the types of the network layer and the transport layer of the existing protocol actually possessed by the computer and the addresses and the allocated virtual addresses are managed in a one-to-one correspondence, so that protocol conversion of datagram packets can be performed at high speed. On the other hand, the application of each computer A common protocol (application software) so that only light processes such as datagrams need to be performed in lower layers of both the layer and the presentation layer.
And the consistency between the session layer and the transport layer in the interface section.

In order to realize this data communication method, the above LA
The physical layer addresses of various computers connected to each other using different types or different protocols by N, the types and addresses of the network layer and the transport layer of the existing protocol actually possessed by each computer, and all the computers in the system Means for managing, in a one-to-one correspondence, a virtual address to which addresses in a network layer and a transport layer of all protocols to be converted are virtually assigned with respect to a physical layer address held by the network. There is also provided a datagram-type protocol conversion adapter having means for performing high-speed datagram packet protocol conversion using management information of the means.

(Operation)

The data communication method according to the present invention is intended for a LAN in which a physical layer address is uniquely determined, and converts a network layer and a transformer of all protocols to be converted to physical layer addresses held by all computers in the system. Since the address in the port layer is virtually allocated,
Each computer does not need to recognize the protocol conversion adapter to be used, nor does it need to be aware that the communication partner uses a different protocol from that of the computer.

This eliminates the need for a special procedure for using the protocol conversion adapter on the computer side.

Also, the physical layer address of each computer and the types and addresses of the network layer and transport layer that each computer actually has and the virtually allocated address are set for the protocol conversion adapter in a one-to-one correspondence. It does not require complicated setting work generally required for gateways.

The application layer and the presentation layer in each computer system require only light processing of about datagrams to the existing lower layer, so that the conventional processing performed in the lower layer can be greatly reduced. Accordingly, the communication processing of each computer becomes faster.

The adapter for protocol conversion is one-to-one as described above.
The management of the corresponding setting information greatly simplifies the protocol conversion process. That is, protocol conversion can be performed at a very high speed.

 With these, high-speed data communication is realized.

Further, the hardware of the protocol conversion adapter can be simplified, and the cost can be reduced.

Further, since a common application protocol consisting of an application layer and a presentation layer on each computer side is connected by an interface between lower layers below the session layer, an interface between the session layer and the presentation layer is provided. It is possible to deal with different lower layers only by changing the ace part.

In this case, this modification is generally easy because the request to the lower layer is about datagram processing, and the interface with the session layer can be simplified. That is, it is easy to cope with the new protocol.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a conceptual diagram showing an example in which an Ethernet (IEEE 802.3 10BASE5) is used as a LAN whose physical layer address is uniquely determined, and a data communication system according to the present invention is realized by using a datagram type protocol conversion adapter according to the present invention. 1 is an external view of a typical system.

FIG. 2 is a conceptual diagram showing a layer model of a protocol, and FIG. 3 is a diagram for explaining an actual flow of a packet and its conversion.

In FIG. 1, a datagram type protocol conversion adapter 6 and computers 7, 8, 9 are connected to a coaxial cable 1 of Ethernet via transceivers 2, 3, 4, 5, respectively.

Both ends of the coaxial cable 1 are terminated by terminating resistors 10 and 11.

FIG. 2 conceptually shows the internal configuration of the system shown in FIG. 1 in accordance with the OSI seven-layer model. Only the computers 7 and 9 are shown with the protocol conversion adapter 6 at the center. . The computer 8 is not shown here.

Since the Ethernet is used as the LAN whose physical layer address is uniquely determined, the physical layer and the data link layer of the protocol conversion adapter 6 and the computers 7 and 9 are all Ethernet 16 and are equivalent.

As application software of a common protocol for realizing the application layer and the presentation layer of the computers 7 and 9 and the computer 8 (not shown), "yaft" is used as an example here.
Datagram-type file transfer program called
think of.

For example, as a session layer, a transport layer, and a network layer of the computer 7, SOCK
Consider the case where the protocols SOCKET13, TCP14, and IP15 called ET, TCP, and IP are used.

Also, as an example, the session layer of the computer 9,
ISO O as transport layer and network layer
It is assumed that the SI protocol is used, and that
Described as 18, TL19, NL20.

The protocol conversion adapter 6 has a datagram packet converter 17 on the Ethernet 16.

The computer 7 includes a physical layer address used in the Ethernet 16, a network layer IP15, and a transport layer TCP.
And have their own address used in 14, each of which,
Indicated as E7 and ADR7.

Similarly, the computer 9 has a physical layer address E9 used in the Ethernet 16, and has a unique address ADR9 used in the network layer NL20 and the transport layer TL19.

Since the protocols defining the addresses ADR7 and ADR9 are different, if the computer 7 and the computer 9 try to communicate with each other through the LAN, the computer 7 cannot accept the address ADR9 of the other party.

Similarly, computer 9 cannot accept address ADR7. Therefore, they cannot communicate with each other as they are.

Therefore, a virtual address is assigned to the computers 7 and 9.

A virtual address conforming to the protocols TCP14 and IP15 used in the transport layer and the network layer of the computer 7 is assigned to the computer 9. This is ADR9 ′
And

Further, a virtual address conforming to the protocols NL20 and TL19 used in the transport layer and the network layer of the computer 9 is allocated to the computer 7. This is ADR7 '.

The correspondence between the physical layer dresses E7 and E9, the real addresses ADR7 and ADR9, the virtual addresses ADR7 'and ADR9', and the types of the transport layers and the network layers of the computers 7 and 9 is determined by the datagram packet of the protocol conversion adapter 6. This is set in the title converter 17.

This correspondence is shown in FIG. The protocol conversion adapter 6 performs protocol conversion at high speed using the table information.

 Next, the operation of this embodiment will be described with reference to FIG.

Now, consider a case where data is transmitted from the computer 7 to the computer 9.

The data issued from the file transfer program yaft12 of the computer 7 is packetized and transmitted as a datagram packet (hereinafter simply referred to as "packet") 21 onto the Ethernet coaxial cable 1.

In this packet 21, E7, A
DR7 is specified.

Further, the computer 7 does not recognize that the computer 9 of the transmission destination has a different protocol, and designates an address of the same protocol as itself in the packet 21 as the transmission destination address.

That is, as the destination address in the packet 21, the physical layer address E9 of the computer 9 and the virtual address
ADR9 'is specified.

This packet 21 is temporarily received by the computer 9, but since it does not have the real addresses of the network layer and the transport layer of the computer 9, it is discarded by the network layer NL20 of the computer 9, and the file of the computer 9 is discarded. It does not reach the transfer protocol yaft12.

However, the protocol conversion adapter 6 monitors all packets flowing on the coaxial cable 1.

Then, the protocol conversion adapter 6 looks at the physical layer address E7 of the transmission source of the packet 21 and the physical layer address E9 of the transmission destination (reception side), and uses these to look up the table of FIG. The packet 21 is composed of the transport layer and network layer protocols TCP14 and IP15 to TL19 and NL20.
At a glance that conversion to is necessary.

Accordingly, the datagram packet conversion unit 17 of the protocol conversion adapter 6 converts the source address ADR7 into an address ADR7 'conforming to the protocol TL19, NL20 virtually allocated to the computer 7, Conversely, the destination address ADR9 ', which is a virtual address assigned to the computer 9, is converted into a real address ADR9 conforming to the protocols TL19 and NL20.

However, the physical layer addresses E7 and E9 are not subject to conversion,
Use as is.

In this way, packet 21 is transformed and packet 22
Is transmitted from the protocol conversion adapter 6 onto the coaxial cable 1, is correctly received by the destination computer 9, and reaches the file transfer protocol yaft 12.

Conversely, when data is transmitted from the computer 9 to the computer 7, the protocol conversion adapter 6 is also spontaneously interposed.

Further, mutual communication is possible between the other computers on the coaxial cable 1 as in the case described above.

In addition, LA with this protocol conversion adapter installed
N and other LANs assigned the same physical layer address,
Even when the connection is made by a bridge, router, or the like according to the prior art, it is possible to automatically convert the datagram packet.

〔The invention's effect〕

As described above, in the data communication method according to the present invention, each computer on the LAN does not need to recognize the protocol conversion adapter used by each, and the communicating party uses a different protocol from itself. Since there is no need to be aware that the protocol conversion adapter is used, no special procedure is required on the computer side for using the protocol conversion adapter.

In addition, there is no need for complicated settings generally required for a gateway.

Furthermore, since the application layer and the presentation layer in each computer system require only the light processing of the datagram level to the existing lower layer, the conventional processing performed in the lower layer is greatly reduced. Can be.

Accordingly, the communication processing of each computer becomes faster. In addition, the protocol conversion adapter also makes protocol conversion processing very easy, and can perform protocol conversion at a very high speed.

 With these, high-speed data communication is realized.

Also, since the hardware of the protocol conversion adapter can be simplified, a low-cost adapter can be provided.

 Furthermore, it is easy to respond to new protocols.

[Brief description of the drawings]

FIG. 1 is an external view of a conceptual system when a data communication system according to the present invention is realized by using a datagram type protocol conversion adapter according to the present invention, and FIG. 2 is also a diagram showing a protocol layer model thereof. FIG. 3 is a conceptual diagram for explaining the flow of a packet and the state of its conversion when performing data communication between computers according to the embodiment shown in FIGS. 2 and 3. FIG. FIG. 4 is an explanatory diagram showing an example of a one-to-one correspondence table managed by a protocol conversion adapter. 1 ... Ethernet (LAN) coaxial cable 2,3,4,5 ... Transceiver 6 ... Datagram type protocol conversion adapter 7,8,9 ... Computer, 10,11 ... Terminal resistor 12 ... yaft (Application software for common protocol) 13 SOCKET, 14 TCP 15 IP, 16 Ethernet 17 Datagram packet converter 18 SL, 19 TL, 20 NL 21,22 …… Datagram packet

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Kitaichi, 9-6, Iwakura Hanazonocho, Sakyo-ku, Kyoto-shi, Kyoto 9 (72) Inventor, Tomohisa Yamamuro 4-20-36, Shibasaki-cho, Tachikawa, Tokyo JP-A-62-283747 (JP, A) JP-A-61-157042 (JP, A) JP-A-2-66057 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04L 12/40 H04L 29/06

Claims (2)

(57) [Claims] In a data communication system between various computers connected by a local area network whose physical layer address is uniquely determined and using different types or different protocols, a datagram packet is stored on the local area network. A network protocol adapter is installed to virtually convert the addresses in the network layer and transport layer of all datagram-type protocols to be converted to the physical layer addresses held by all computers in the system. The assignment of the physical layer address of each computer, the type and address of the network layer and the transport layer of the existing protocol that the computer actually has, and the assigned virtual address by the protocol conversion adapter. Manage with one correspondence The protocol conversion of the datagram packet is performed at high speed. On the other hand, in both the application layer and the presentation layer of each of the above-mentioned computers, only the light processing such as the datagram needs to be performed in the lower layers. A data communication method characterized by creating a common protocol and measuring consistency between a transport layer and a session layer and its interface. 2. A datagram type protocol conversion adapter used in a data communication system according to claim 1, wherein said computers are connected to each other by said local area network and are of different models or use different protocols. Physical layer address, the type and address of the network layer and transport layer of the existing protocol that each computer actually has, and the physical layer address of all protocols in the system that are owned by all the computers in the system. Means for managing the addresses in the network layer and the transport layer in a one-to-one correspondence with virtual addresses virtually allocated, and using the management information of the means to perform high-speed protocol conversion of datagram packets Datagram type protocol characterized by comprising means for performing Conversion adapter.