JP2001144828A - Protocol converter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make available a peripheral device connected to a network from a computer without being aware of the network. A protocol conversion device (20) is connected to a host computer (10) via a USB (80).
The printers 40 and 50 and the scanner 60 connected to the USB port 0 behave as if they were connected to the USB 80.
The protocol conversion device 20 logically operates as a USB-HUB 20 ′ for the host computer 10, and the printers 40 ′, 50 ′ and the scanner 60 ′ are peripherally connected via the USB-HUB 20 ′. It can be used as a device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protocol converter for connecting a network for information communication with a transmission line for connecting peripheral devices of a computer.

[0002]

2. Description of the Related Art Conventionally, a plurality of computers and peripheral devices have been used by being mutually connected by a network. A relatively small network is Local Ar
It is abbreviated as LAN from ea Network. When a network is formed, resources such as peripheral devices can be shared by a plurality of computers, and efficient information processing can be performed. In order to smoothly use peripheral devices from a plurality of computers on the LAN, information communication on the LAN is performed according to a predetermined protocol. As LAN, product name 10BaseT or 100B
Using a transmission cable called aseT, TCP
/ IP (Transmission Control Protocol / Internet Pr
A method using a protocol called otocol) is widely used.

A personal computer or the like has an input / output function for directly connecting peripheral devices such as a printer and a scanner. Personal computer is also LA
Although it is possible to connect and use peripheral devices, it is possible to configure a compact system by directly connecting peripheral devices. Data transmission between a personal computer and a peripheral device is generally performed in character units. On the other hand, communication of information on a LAN is performed by adding a header or the like specifying a destination and a source as a packet in which a certain amount of data is put together.

Japanese Patent Laid-Open No. Hei 10-233820 discloses a LAN system that connects a LAN system that performs information communication in units of packets and a serial terminal system that performs communication in units of characters.
A data transmission method that enables communication between a host computer on N and a serial terminal has been proposed. JP 1
In 0-233820, character data is extracted from the LAN packet and transmitted to the serial terminal, and the character data sent from the serial terminal is encapsulated and
A method of shaping the packet as an AN packet is proposed. Further, a method has been proposed in which a unique header is added to a LAN packet, and a plurality of serial terminals are controlled by interpreting the header.

[0005]

However, in the prior art proposed in JP-A-10-233820, L
The AN controls peripheral devices connected to the serial bus, and the serial terminal simply returns a response to the host computer on the LAN.

Generally, in order to use a peripheral device connected to a LAN, a host computer includes an interface device for connecting to the LAN as hardware, and further specifies a peripheral device to be used on the interface device. Therefore, it is necessary to perform various settings according to the protocol. Further, when a visitor uses the network, security problems arise due to the setting of access rights and the like.

[0007] It is an object of the present invention to provide a protocol conversion apparatus which makes it possible to easily use peripheral devices connected to a network from a computer not directly connected to the network.

[0008]

According to the present invention, a network for performing information communication by a packet switching system according to a predetermined protocol and a transmission line for performing data transmission between a computer and a peripheral device according to a predetermined transmission standard are provided. A protocol conversion device for connecting the network and the transmission line by protocol conversion, wherein information holding means for holding information necessary for conversion between data conforming to the transmission standard and packets conforming to the protocol; A computer connected to the transmission line, performing conversion between data conforming to the transmission standard and packets conforming to the protocol, based on information held by the information holding unit;
Packet switching means for mediating between peripheral devices connected to the network, and conversion control means for controlling the packet switching means to enable the computer to use the peripheral device as a peripheral device on the transmission line. And a protocol conversion device.

According to the present invention, the protocol conversion device comprises:
Connected to network and transmission line. The network performs information communication by a packet switching method according to a predetermined protocol. The transmission line performs data transmission between the computer and the peripheral device according to a predetermined transmission standard. The protocol conversion device includes an information holding unit, a packet switching unit, and a conversion control unit. The information holding means is
It holds information necessary for conversion between data conforming to the transmission standard and packets conforming to the protocol. The packet switching means, based on the information held by the information holding means,
It performs conversion between data conforming to a transmission standard and packets conforming to a protocol, and mediates between a computer connected to a transmission line and a peripheral device connected to a network. The switching control means controls the packet switching means to enable the peripheral device from the computer to be used as a peripheral device on the transmission line. From the computer connected to the transmission line, peripheral devices connected to the network can be used as peripheral devices on the transmission line, so there is no need for hardware or software for connecting to the network.
Peripherals connected to the network can be used.

In the present invention, the information holding means may include information on a type of a peripheral device connected to the network, and an operation as a virtual peripheral device connected to the transmission line of the same type as the peripheral device. The conversion control means further includes: the conversion control means that, based on the information held in the information holding means, a peripheral device connected to the network directly connects the computer to the transmission line based on the information held in the information holding means. It is characterized by performing control to behave as described above.

According to the present invention, the information holding means includes information on the type of the peripheral device connected to the network and the status as the virtual peripheral device connected to the transmission line of the same type as the peripheral device. Information is retained. The conversion control means makes the computer behave as if the peripheral device connected to the network is directly connected to the transmission line based on the information held in the information holding means. Can be used in the same way as peripheral devices connected via the.

Further, in the present invention, even when a plurality of peripheral devices are connected to the network, only information relating to peripheral devices usable from a computer connected via the transmission line is stored in the information holding means. It is characterized by the following.

According to the present invention, even if a plurality of peripheral devices are connected to the network, only the peripheral devices whose information is held in the information holding means can be used. By making only peripheral devices having no problem even available from the transmission line, access to an inappropriate network can be suppressed and network security can be improved.

Further, in the present invention, a plurality of the transmission lines can be connected, provided for each transmission line, and usage status storage means for storing usage status of a peripheral device from a computer connected to the transmission line; A usage management unit configured to manage usage requests to the peripheral device from the plurality of computers based on the usage status stored in the usage status storage unit.

According to the present invention, when a computer is connected to each of a plurality of transmission lines and a peripheral device is used, the usage status of the peripheral device from the computer is stored in the usage status storage means for each transmission line. The usage management unit manages usage requests for peripheral devices from a plurality of computers based on the usage status stored in the usage status storage unit.
Even if a plurality of computers make a request for use of a specific peripheral device and a conflict occurs, the right to use the peripheral device is adjusted by the use management means, and the use of the peripheral device can be smoothly adjusted.

According to the present invention, there is also provided a host registering means for registering a host computer connected to the network as a specific host in advance, receiving a packet transmitted from the network, and transmitting the packet based on the protocol. When the source identified by the source identification unit and the source identified by the source identification unit match a specific host registered in the host registration unit, the packet is interpreted as a command packet and included in the packet. According to the present invention, further comprising a packet interpreter for executing a command, a host computer connected to the network is registered in the host registerer in advance as a specific host. The source identification means receives a packet transmitted from the network and identifies the source of the packet based on the protocol. The packet interpreter interprets the packet as an instruction packet and executes a command included in the packet when the source identified by the source identifier matches a specific host registered in the host register. By transmitting a command packet from a specific host computer, operations such as registration, change, or deletion of information held by the information holding unit can be performed from the host computer registered in the host registration unit.

In the present invention, the host registration unit registers the specific host in the information holding unit.

According to the present invention, the host registration unit registers the specific host in the information holding unit, so that the processing by the packet conversion unit and the packet interpretation unit can be performed quickly.

In the present invention, the transmission line is a USB.

According to the present invention, a USB
The peripheral device connected to the network can be used as the peripheral device connected to the network. The use of the peripheral device connected to the USB can be performed more easily than the use of the peripheral device connected to the network, and the use of the peripheral device can be achieved with a simple configuration.

Further, the present invention is a computer-readable recording medium in which a program for causing a computer to function as the above-mentioned protocol conversion device is recorded.

According to the present invention, by causing a computer to read a program, a peripheral device on a network can be used as a peripheral device on a transmission line from another computer connected to the computer via the transmission line. Can be

[0023]

FIG. 1 shows a schematic system configuration relating to a protocol conversion device as one embodiment of the present invention. FIG. 1A shows an actual physical device configuration, and FIG. 1B shows a logical device configuration. The host computer 10 is, for example, a personal computer, and is connected via a protocol converter 20 to a control host computer 30 and a LAN 70 to which peripheral devices such as printers 40, 50 and a scanner 60 are connected. LAN 70 is 10BaseT, 100Base
are connected to each other via transmission cables 71, 72, 73,... such as eT. Although omitted for convenience of explanation, other computer devices can be connected to the LAN 70. A Universal S is provided between the host computer 10 and the protocol converter 20.
U, which is a serial transmission line called "rial bus"
Connected by SB80.

FIG. 1B shows a logical device configuration recognized by the host computer 10. The host computer 10 is connected to the protocol conversion device 20 via the USB 80. The protocol conversion device 20 converts the protocol so that peripheral devices such as the printers 40 and 50 and the scanner 60 connected to the LAN 70 can be seen as peripheral devices on the USB 80. As a result, the host computer 10
Therefore, the protocol conversion device 20 includes a USB-HUB 20 ′ which is a hub for branching the USB 80 to a plurality of peripheral devices.
Will be recognized as The printers 40 and 50 and the scanner 60 as peripheral devices connected to the LAN 70 are logically connected to the printer 4 connected from the USB-HUB 20 ′.
USB-HU can be used as 0 ', 50'
B20 'can be regarded as being connected by USB 81', 82 ', 83'.

FIG. 2 shows the internal configuration of the protocol converter 20 of FIG. The protocol conversion device 20 includes an interface (hereinafter abbreviated as “I / F”) USB I / F 201 for connecting to the USB 80 shown in FIG. The USB I / F 201 is connected to a USB packet transmitting / receiving unit 202. USB packet transmitting / receiving unit 20
2, a USB packet synthesis unit 203 and a USB packet analysis unit 204 are connected. USB packet analyzer 20
4 provides the analysis result to the USB header separation unit 205. The USB packet combining unit 203 includes a LAN-U
Outputs from the SB data buffer 206 and the LAN-USB header conversion unit 207 are input. LAN-USB
The header conversion unit 207 is controlled by the packet switching control unit 208. The packet switching control unit 208
It also controls the packet analyzer 204 and the USB-LAN header converter 209. USB-LAN header conversion unit 2
09 is supplied with an output from the USB header separation unit 205. The output from the USB header separation unit 205 is
It is also provided to the B-LAN data buffer 210.

The output from the LAN header separation unit 211 is given to the LAN-USB data buffer 206 and the LAN-USB header conversion unit 207. The output from the LAN packet analysis unit 212 is provided to the LAN header separation unit 211. The LAN packet analysis unit 212 is controlled by the packet conversion control unit 208. USB-
Outputs from the LAN header conversion unit 209 and the USB-LAN data buffer 210 are output from the LAN packet synthesis unit 2.
13 is given. The output from the LAN packet combining unit 213 is provided to the LAN packet transmitting / receiving unit 214 together with the output from the LAN packet analyzing unit 212. LA
The N packet transmitting / receiving unit 214 performs data communication in a packet format with the LAN 70 shown in FIG. 1 via the LAN I / F 215.

That is, data received from the USB 80 via the USB I / F 201 is input to the packet conversion control unit 208 via the USB packet transmitting / receiving unit 202 and the USB packet analyzing unit 204, and is sent to the LAN packet analyzing unit 212 and the LAN Packet transmitting / receiving section 214 and LA
The data is transmitted to the LAN 70 via the N I / F 215. L
Received from AN 70. The packet is sent to the LAN I / F
215 to LAN packet transmitting / receiving section 214 and LAN
Packet conversion control unit 20 via packet analysis unit 212
8 and transmitted to the USB 80 via the USB packet analysis unit 204, the USB packet transmission / reception unit 202, and the USB I / F 201.

The USB packet transmission / reception unit 203 includes a USB
The I / F 201 passes the USB packet received from the host computer 10 to the USB packet analysis unit 204, and conversely, transfers the packet generated by the USB packet synthesis unit 203 or the USB packet analysis unit 204 to the USB I / F 20.
1 to the host computer 10. USB
The packet analysis unit 204 classifies the received packet into a data stream and a control packet, sends the data stream to the USB header separation unit 205, generates a response packet, and sends it back to the USB packet transmission / reception unit 202.
The control packet is sent to the packet conversion control unit 208, and the response packet is received and passed to the USB packet transmitting / receiving unit 202.

The USB header separation unit 205 separates the received packet into a header portion including a token packet and a frame start packet and a data portion including a data packet, and passes the header portion to the USB-LAN header exchange unit 209. , The data portion is passed to the USB-LAN data buffer 210. The USB-LAN header exchange unit 209 obtains the IP address of the transmission destination and the IP address of the protocol conversion device 20 by referring to the USB-IP conversion table of the packet conversion control unit 208.
A / IP header is generated and passed to the LAN packet combining unit 213. The LAN packet synthesizing unit 213 outputs the received TC
P / IP header and USB-LAN data buffer 210
Then, a TCP / IP packet is generated by synthesizing the data with the data in the LAN, and is passed to the LAN packet transmitting / receiving unit 214. The LAN packet transmitting / receiving unit 214 receives the TCP / IP received from the LAN packet combining unit 213 and the LAN packet analyzing unit 212.
The packet is transmitted from the LAN I / F 215 to the LAN 70, and the packet received from the LAN 70 is passed to the LAN packet analysis unit 212.

The LAN packet analysis unit 212 analyzes the header of the received TCP / IP packet, and if the packet is from a peripheral device registered in the USB-IP conversion table of the packet conversion control unit 208, the LAN packet separation unit 212 Hand over to section 211. Further, a response packet is generated, and L
It is passed to the AN packet transmitting / receiving unit 212. If the packet is from the control host computer 30 as shown in FIG. 1, the packet is passed to the packet conversion control unit 208, and the returned response packet is passed to the LAN packet transmitting / receiving unit 214.

In the LAN header separating section 211, TCP /
The IP packet is separated into a TCP / IP header and a data part, and the header is converted to a LAN-USB header conversion unit 207.
And the LAN-USB data to the data buffer 206. The LAN-USB header conversion unit 207 refers to the USB-IP conversion table of the packet conversion control unit 208, acquires a USB address from the IP of the transmission source of the TCP / IP header, generates a USB header, and generates a USB header. The packet is passed to the packet synthesizer 203. USB packet synthesizer 203
Generates a USB data stream using the received USB header and the data in the LAN-USB data buffer 206 and sends the data stream to the USB packet transmitting / receiving unit 202. The packet conversion control unit 208 has a USB-IP conversion table as information holding means, and searches the contents of the table in response to a request from the LAN-USB or USB-LAN header conversion units 207 and 209.

FIG. 3 shows the packet conversion control unit 208 of FIG.
2 shows an outline of the USB-IP conversion table 300 provided in FIG. Information about peripheral devices used by the host computer 10 is registered and held in the USB-IP conversion table 300. DEVICE ID uniquely assigned to the registered device to distinguish peripheral devices
USB A allocated from the host computer 10
DDRESS, IP ADDRESS for specifying a peripheral device on the LAN 70, and DEVICE CLASS for specifying the type of the peripheral device.

Next, a procedure for registering a new peripheral device as a device in the USB-IP conversion table 300 will be described. The IP address and the type of the peripheral device set in the peripheral device in advance are input to the USB-IP conversion table 300. DEVICE I which does not overlap with other peripheral devices
Append D to add an empty row for USB ADDRESS. For the added peripheral device, the packet conversion control unit 208 sends a USB
Notify of device reconfiguration and Universal Se
real Bus Specification 9.
Bus Enumeratio specified in 1.2
The USB device is registered in the host computer 10 according to the procedure of n. The USB device descriptor and configuration descriptor required at this time are DEV
It is generated from the device type defined in the ICE CLASS and the specified value of the protocol converter 20. Then, in the bus enumeration procedure 6, the address assigned from the host computer 10 is set to U
Register for SB ADDRESS. The IP address of the protocol conversion device 20 is also registered as the HOST 301 in the USB-IP conversion table 300,
The LAN header conversion unit 209 is used to generate a TCP / IP header. Similarly, the IP address of the control host computer 30 is also stored in the USB-IP conversion table 300 by the CN.
The packet is registered like the TL 302 and used by the LAN packet analysis unit 212 to identify a packet from the control host computer 30.

Next, the TCP / I from the control host computer 30 detected by the LAN packet analysis unit 212
A procedure for analyzing a P packet and executing a command included in the packet will be described. First, the header from the packet from the control host computer 30 is removed, leaving only the data portion including the command. Next, the type of the command is specified by referring to the first byte. According to the type of command, the second and subsequent bytes are interpreted as arguments and the command is executed.

FIG. 4 shows a device addition command for adding a peripheral device. FIG. 4A shows the processing procedure of the command, and FIG. 4B shows the components of the corresponding packet. In the header separation in step a1, except for the header 4011 of the control packet 401, the command section 401
2 to obtain a data portion 402. Next, in the analysis of the command in step a2, the command 4021 consisting of the first few bytes of the data portion 402 is referred to, and the command 4021
Identify the type of In determining the format of the argument in step a3, the data part 4 is determined in accordance with the specified command 4021.
The format of the argument portion 4022 excluding the command 4021 from 02 is determined. In accordance with this determination, in step a4, as the argument 403 from the argument part 4022, the device IP address 4031 and the device type information 4032 necessary for adding the device are read and acquired. In the execution of the command in step a5, the IP address 4031
Then, the device type information 4032 is added to the USB-IP conversion table 300.

With the configuration described above, FIG.
The protocol conversion device 20 in FIG. 1A transmits the printers 40 and 50 and the scanner 60 as peripheral devices on the LAN 70 specified by the control host computer 30 to the host computer 10 as shown in FIG. Printers 40 ', 50' and scanner 6 which are USB peripheral devices
It can be recognized as 0 '. As a result, the host computer 10 can transmit and receive data to and from peripheral devices without being conscious of the LAN 70 network.

FIG. 5 shows a schematic configuration of a protocol conversion device 500 as another embodiment of the present invention. In the protocol conversion device 500 according to the present embodiment, portions corresponding to those of the protocol conversion device 20 illustrated in FIG. 2 are denoted by the same reference numerals, and redundant description will be omitted. The protocol converter 500 according to the present embodiment is the same as the protocol converter 2 shown in FIG.
0, two USB I / Fs 201a, 2 instead of one USB I / F 201 provided.
01b, and a device management unit 217 is further added. The plurality of USB I / Fs 201a and 201b communicate with the host computer similarly to the protocol conversion device 20 of the embodiment of FIG. 1 except that each of the USB I / Fs 201a and 201b has a different ID and is connected to a different host computer. And send and receive data.

The LAN packet transmitting / receiving unit 202 is a USB
Along with the packet received from one of the I / Fs 201a and 201b, the USB I / F 201a and 201b
The ID of b is passed to the USB packet analysis unit 204. Also,
The USB packet combining unit 203 sends the packet
The I / F 201a or 201b receives the ID of the I / F 201a or 201b, and the USB I / F 201a or 201 designated by the ID.
Pass the packet to b. The USB packet analysis unit 204
USB I received from USB packet transmitting / receiving section 202
The ID of / F is transferred to the device management unit 217 together with the address of the USB device. Otherwise, the packet is analyzed and the response packet is transmitted as in the embodiment of FIG.

In the LAN-USB header conversion unit 207,
After converting the IP header to a USB header, the destination U
The IDs of the SBI / Fs 201a and 201b are specified and passed to the USB packet combining unit 203 together with the header. The USB packet synthesizing unit 203 sends the USB I / Fs 201a and 201b of the destination together with the data stream generated from the header received from the LAN-USB header converting unit 207 and the data in the LAN-USB data buffer 206.
To the USB packet combining unit 203. The device management unit 217 has a usage status management table and a clock function, and searches the contents of the usage status management table in response to a request from the LAN-USB header conversion unit 207. US
USB ID and U passed from B packet analyzer 204
The usage status management table is updated according to the SB address, and is notified to the packet conversion control unit 208. The packet conversion control unit 208 searches the USB-IP conversion table 300 according to the request from the device management unit 217. When a notification of contention is received from the device management unit 217, a packet that informs the host computer 10 via the USB packet analysis unit 204 that the peripheral device for which use has been requested cannot be used. return it. The operation in other cases is the same as that of the protocol conversion device 20 of the embodiment in FIG.

FIG. 6 shows a USB provided in the packet conversion controller 208 of the protocol converter 500 according to the present embodiment.
-Indicates the contents of the IP conversion table 600. In the USB-IP conversion table 600 of the present embodiment, the registration content
A USB ID indicating the ID of the B I / F is added. Since the USB address is obtained for each host computer, each device has a plurality of USB addresses. That is, "2" is used as the DEVICE ID.
Is assigned to a printer with a USB ID of “1”.
U for host computer connected to B I / F
SB ADDRESS is "aaa", whereas U
USB ADDRESS for the host computer connected to the USB I / F whose SB ID is “2”
Becomes “ddd”. IP ADDR on LAN 70
ESS is xxx. xxx. xxx. yyy, and DEVICE CLASS is the same in Printer. This is a matter of course because the physically same printer connected to the LAN 70 is targeted.

FIG. 7A shows the device management unit 2 of FIG.
17 shows an outline of the usage management table 700 provided in FIG. 17, and (b) shows a usage request from the host computer. In the usage status management table 700, information on the currently used peripheral devices and the host computer using them is registered. The registered contents indicate a USB ID indicating a USB I / F to which a host computer using the peripheral device is connected, a DEVICE ID indicating a used peripheral device, and a time at which the peripheral device is released. RELEASE TIME is included. When the device management unit 217 receives a request to use a peripheral device from the USB packet analysis unit 204,
The B ID and the USB address are passed. The device management unit 217 obtains a DEVICE ID from the USB-IP conversion table 600 of the packet conversion control unit 208 using the transferred USB ID and USB address, and the DEVICE ID is registered in the usage status management table 700. Search whether it is. DEVICE ID
If the peripheral device is not found, it is determined that the peripheral device is not being used by another host computer connected by USB, the USB ID and the DEVICE ID are registered in the usage status management table 700, and the peripheral device is fixed at the current time. The time obtained by adding the time is registered in RELEASE TIME. This registration content is that the current time is RELEASE TI
It is deleted when it exceeds ME.

It is assumed that the usage status management table 700 is searched for the peripheral device having the DEVICE ID “2”. In response to a use request as indicated by 701 in FIG. 7B, it is determined that the corresponding peripheral device is not used. For the use requests shown in 702 and 703, D
It is determined that "2" is used as the EVICE ID, and it is determined that the peripheral device is in use. The request for use of this peripheral device is a USB I / I with a USB ID of “1”.
7 from the host computer connected to F
In the case shown in FIG. 02, it is determined that continuous use is in progress, and RELEASE TIME of the use status management table 700 is calculated again from the current time and re-registered. If the USB IDs are different as shown in 703, it is determined that there is a conflict between peripheral device use requests, and a notification is sent to the packet conversion control unit 208.

With the above-described configuration, a plurality of host computers can be connected to the protocol converter 500, and each host computer can exclusively use peripheral devices on the LAN 70.

In each of the embodiments described above, the communication between the host computer and the protocol
Although connected by SB80, other serial communication transmission lines such as IEEE 1394 and RS232C can be similarly connected. In addition, not only a transmission line for serial communication but also a transmission line for parallel communication such as SCSI and IEEE-488 GP-IB can be used. Further, connection can be made by infrared communication such as IrDA. If a converter for converting between the standard used for these communications and the LAN protocol is provided, peripheral devices can be used without being aware of the network of the LAN 70 from the computer as in the present invention.

The protocol converters 20 and 500
Can be configured using a general-purpose computer without necessarily using a dedicated device. The same functions as those of the protocol converters 20 and 500 can be given to a computer by a program, and another computer can use a peripheral device on the LAN. A program for operating as a protocol conversion device is a floppy disk (FD), a CD-ROM, a DVD-R
The data can be read by a computer from a large-capacity recording medium such as an OM, or downloaded by a download via a communication line such as the Internet.

[0046]

As described above, according to the present invention, a peripheral device connected to a network can be used from a computer not connected to the network via a transmission line for connecting the peripheral device. .

According to the present invention, a peripheral device connected to a network can be used from a computer not connected to the network to a peripheral device directly connected to a transmission line of the computer.

Further, according to the present invention, among the peripheral devices connected to the network, only the peripheral devices whose predetermined information is held in the information holding means can be used from a computer not connected to the network. To limit access to inappropriate networks,
Network security can be improved.

Further, according to the present invention, when a use request from a computer connected via a plurality of transmission lines to a peripheral device connected to a network conflicts, according to the information stored as the use status, The usage request can be adjusted and the peripheral devices connected to the network can be used smoothly.

Further, according to the present invention, a specific host computer connected to the network can set or change information relating to the protocol conversion function.

Further, according to the present invention, by referring to the information held in the information holding means, it is determined whether the packet transmitted and received from the network is data to be transmitted to the computer via the transmission line or not. Can be quickly identified.

Further, according to the present invention, the computer
Similar to using the peripheral device via B, the peripheral device connected via the network can be used.

Further, according to the present invention, a computer is connected to a network, and a peripheral device connected to the network is connected to a peripheral device connected to the transmission line from another computer connected via the transmission line. It can be used similarly.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an actual device configuration related to a protocol conversion device 20 according to an embodiment of the present invention and a logical device configuration recognized by a host computer.

FIG. 2 is a block diagram showing an electrical configuration of a protocol conversion device 20 of FIG.

FIG. 3 is a table showing an outline of a USB-IP header conversion table 300 provided in the packet conversion control unit 208 of FIG. 2;

FIG. 4 is a flowchart showing a procedure in which the protocol conversion device 20 of FIG. 1 executes a command from a control host computer 30 connected to a LAN 70, and a diagram showing a packet configuration.

FIG. 5 is a block diagram showing an electrical configuration of a protocol conversion device 500 according to another embodiment of the present invention.

FIG. 6 is a table showing an outline of a USB-IP header conversion table 600 provided in the packet conversion control unit 208 of FIG.

FIG. 7 is a chart showing an outline of a usage status management table 700 provided in a device management unit 217 of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Host computer 20,500 Protocol conversion device 20 'USB-HUB 30 Control host computer 40, 50; 40', 50 'Printer 60; 60' Scanner 70 LAN 80 USB 201, 201a, 201b USB I / F 202 USB packet Transmission / reception section 203 USB packet synthesis section 204 USB packet analysis section 205 USB header separation section 207 LAN-USB header conversion section 208 Packet conversion control section 209 USB-LAN header conversion section 211 LAN header separation section 212 LAN packet analysis section 213 LAN packet synthesis Unit 214 LAN packet transmission / reception unit 215 LAN I / F 217 device management unit 401 control packet 402 data portion 403 argument 700 usage management table

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) BB06 DD01 EE11 FF04 FF06 FF11 HH01 HH02 HH04 HH06 HH13 HH61 KK21 SS01 9A001 BB04 CC06 CZ08

Claims (8)

[Claims] 1. A network for performing information communication by a packet switching system according to a predetermined protocol, and a transmission line for performing data transmission between a computer and a peripheral device according to a predetermined transmission standard, wherein the network and the transmission line are connected. A protocol conversion device that connects between the data and the data according to the transmission standard and a packet according to the protocol by a protocol conversion device. Packet switching means for performing conversion between data conforming to the transmission standard and packets conforming to the protocol based on the information, and mediating between a computer connected to the transmission line and a peripheral device connected to the network And controlling the packet switching means to transfer the peripheral device from the computer to the transmission line. And a conversion control means for enabling the device to be used as a peripheral device. 2. The information holding means includes information on the type of peripheral device connected to the network and a state of operation as a virtual peripheral device connected to the transmission line of the same type as the peripheral device. Further, the conversion control means, based on the information held in the information holding means, for the computer, the peripheral device connected to the network, directly connected to the transmission line 2. The protocol conversion device according to claim 1, wherein the protocol conversion device performs control to behave as if it were. 3. The information holding unit stores only information on peripheral devices usable from a computer connected via the transmission line, even if a plurality of peripheral devices are connected to the network. Claim 2
The described protocol converter. 4. A plurality of transmission lines are connectable, provided for each transmission line, and usage status storage means for storing usage status of a peripheral device from a computer connected to the transmission line; 4. The protocol conversion apparatus according to claim 1, further comprising: a use management unit that manages a use request from a computer to a peripheral device based on the use status stored in the use status storage unit. apparatus. 5. A host registration unit for registering a host computer connected to the network as a specific host in advance, receiving a packet transmitted from the network and identifying a transmission source of the packet based on the protocol. When the source identification unit and the source identified by the source identification unit match a specific host registered in the host registration unit, interpret the packet as an instruction packet and execute a command included in the packet. 5. The protocol conversion device according to claim 1, further comprising: a packet interpreting unit that performs the packet interpretation. 6. The protocol conversion apparatus according to claim 5, wherein said host registration means registers said specific host in said information holding means. 7. The protocol converter according to claim 1, wherein the transmission line is a USB. 8. A computer-readable recording medium in which a program for causing a computer to function as the protocol conversion device according to claim 1 is recorded.