JP2000035930A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the network system of a multi-protocol environment capable of automatically selecting an appropriate protocol and performing communication between devices connected through a network without troubling a user for protocol setting. SOLUTION: In this network system of the multi-protocol environment composed by interconnecting the plural devices 1 and 2 respectively capable of selectively using the plural kinds of the protocols through a LAN 100, the respective devices 1 and 2 hold parameter information for indicating the priority of the respective characteristics of the protocols A, B, C,... and C, D, E,... usable by them, and at the time of the communication obtain the parameter information from the opposite device by the management protocol X of a high- order layer, compare it with the parameter information of the present device, automatically select the protocol matched with the protocol usable by the present device whose priority in the present device is higher and perform the communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a network system in a multi-protocol environment.

[0002]

2. Description of the Related Art Many local area networks (hereinafter, referred to as LANs), which are now widely used, are operating systems of clients and servers (for example, Windows).
Multiple protocols supported by s95, WindowsNT, UNIX, etc. (TCP / IP, IPX / SPX, NetBEUI, Appl
eTalk, DLC, etc.) are often used in a multi-protocol environment where communication is selectively performed. In a multi-protocol environment, it is possible to connect to a partner with a different OS by using a protocol according to the partner, so that a network system in which devices of different manufacturers and models are mixed can be constructed.

[0003]

However, since the partner device to communicate with does not necessarily support all the same protocols as its own device, the user determines which protocol to select during communication. May get lost. For example, in a multi-protocol LAN connecting a plurality of terminal devices such as a personal computer (hereinafter, referred to as a PC) and a plurality of peripheral devices such as a printer, a peripheral device using a certain terminal device may be used. To transmit data to the terminal device, the user of the terminal device has to decide which protocol is to be used for communication.
The only option is to use the function of another utility program of the terminal device to check, or to actually go to the peripheral device of the other party to check. In addition, even if the protocol that can be used by the peripheral device of the other party is known, the appropriate protocol is selected because the protocol is appropriate or inappropriate depending on the network form, purpose of use, operation rules, etc. Requires expertise. Therefore,
An object of the present invention is to provide a multi-protocol environment in which an appropriate protocol can be automatically selected and communicated between devices connected via a network without bothering a user for setting a protocol. In providing a network system.

[0004]

According to the first aspect of the present invention, a plurality of devices each capable of selectively using a plurality of protocols are interconnected via a network. In a network system in a multi-protocol environment, each of the devices holds parameter information indicating a priority of each characteristic of a protocol that can be used. Comparing with the parameter information of the device,
Communication is performed by automatically selecting a protocol that matches a protocol that can be used by the own device and has a higher priority in the own device. According to a second aspect of the present invention, in the network system according to the first aspect, a protocol used in each of the devices and a priority order thereof can be collectively set via a network. According to a third aspect of the present invention, in the network system according to the second aspect, each of the devices invalidates a protocol not specified as a protocol to be used.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an embodiment of the present invention. A network system in which a PC 1 as a terminal device and a printer 2 as an example of a peripheral device are communicably connected via a LAN 100 is shown. Is shown. Note that a PC is actually connected to LAN3.
Other devices are connected in addition to 1 and printer 2,
Here, in order to simplify the explanation, the simplest system configuration example as shown in the figure will be described. The PC 1 supports protocols A, B, C, D, and E, and the printer 2
Supports protocols C, D, E, F, and G. That is, PC1 has a plurality of protocols A, B, C,
A device that can perform communication by arbitrarily selecting and using one of D and E. The printer 2 arbitrarily selects and uses one of a plurality of protocols C, D, E, F, and G It is a device that can perform communication. PC1 and Printer2
Holds parameter information indicating the priority of each characteristic of the protocol supported by each in a memory (not shown) as a table as shown in FIG. As shown in the figure, in each parameter information, items 1 to 5 correspond to one protocol, and items of a protocol name, a function, a performance, and a priority value are provided for each protocol. In the item of protocol name, symbols (A, B,
C, D, etc.) are written. In the items of function, performance, and priority value, the characteristic value of each protocol when these are used as parameters is written as an integer from 1 to 10, for example. Here, it is assumed that the larger the numerical value, the better the characteristic. The priority value is a numerical value representing the individual circumstances of each device (PC1, printer 2) different from the function and performance of the protocol. With respect to the function and performance values, the existence of a plurality of protocols having the same value is allowed, but the priority values are all different for each protocol.

FIG. 3 shows a data hierarchical structure (layer structure) of the network system according to this embodiment. As shown, each of the devices 1 and 2 has various protocols (A,
B, C, D, etc.) and the uppermost layer, the upper layer for referring to the parameter information (P) shown in FIG. It has a protocol (hereinafter, referred to as a management protocol) layer. The management protocol X is a protocol that supports all transport protocols and does not depend on the protocols of the various protocol layers. That is, in this embodiment, by using the management protocol X,
Each of the devices 1 and 2 has an arbitrary protocol (A, B, C, D,
, Etc.) so that it is possible to try to obtain the parameter information of the other party.

Next, the operation of this embodiment configured as described above will be described. FIG. 4 illustrates a procedure for obtaining parameter information between two devices communicably connected via a network. For example, when the device 1 starts communication with the device 2, On the other hand, first, a request for acquiring the parameter information P is issued by the protocol A. If there is no response in this protocol A,
Next, the device 1 issues a request for acquiring the parameter information P by the protocol B in the same manner. The device 1 acquires the parameter information P from the device 2 by repeating this parameter information acquisition operation. In the example of FIG. 4, there is a response from the device 2 when the acquisition request of the parameter information P is issued by the protocol C,
This shows a case where the parameter information P of the device 2 can be obtained. If a response is not obtained from the device 2 even after repeating the parameter information acquisition operation, it is determined that there is no protocol that can communicate between the device 1 and the device 2. When the parameter information P of the device 2 can be obtained as described above, the device 1 compares the parameter information P with each other and extracts the one having the largest characteristic value of performance or function from the common protocol. , A protocol used for communication with the device 2 is selected.

FIG. 5 illustrates a processing flow when a protocol is selected with priority given to performance.
When the parameter information P of the device 2 can be obtained, the parameter information P is compared with each other, and first, a common protocol (in this case, C, D, and E) is extracted (S1). Largest protocol (C and D in this case)
Is extracted (S2). If one protocol satisfies the condition (No in S3), the protocol is determined as the protocol to be used.
Yes), the protocol with the highest priority value (D in this case) is extracted, and this is determined as the protocol to be used.
Also, when selecting a protocol with priority on functions,
In step S2 of the processing flow of FIG. 5, the processing content may be changed so as to extract the protocol having the largest function value.

FIG. 6 shows commands given by the management protocol X to each device and their specifications (contents of commands). In the above case, the device 1 receives the information acquisition command Get.
The contents of the parameter information P of the device 2 are read according to (p, n), and the extraction protocol of steps S1 to S3 is performed to select a protocol to be used. Information on the selected used protocol is transmitted to the device 2 as a management protocol setting command Set (p, n). The device 2 that has received the setting command Set (p, n) rewrites its own parameter information to the value specified by the setting command Set (p, n). (The above corresponds to claim 1)
In the above, the case of setting the protocol between the two devices 1 and 2 has been described, but as shown in FIG.
When a large number of devices 1, 2, 3,..., N are connected to the LAN 100, for example, all devices 1, 2, 3,.
Broadcasts the setting command Set (p, n) of the management protocol X in response to the request. Setting command Set (p,
All the devices that have received n) set each parameter information (protocol and its priority) with the setting command Set (p,
Rewrite to the value specified in n). Thus, the protocols used in the devices 1, 2, 3,..., N and their priorities are collectively set via the LAN 100. As a result, for example, 1
When a priority value from 7 to 7 is assigned, the protocol G is selected with the highest priority according to the processing flow of FIG. 5, and when this is not available, the protocol F is selected. Communication is performed using the optimal protocol.

As described above, the parameter information (protocols and their priorities) are collectively set for all the devices 1, 2, 3,... On the LAN 100, and according to the rules (network policy) relating to the operation of the set network. In this way, by using a protocol with a high priority value in a unified and preferential manner on a network basis and performing communication, it is possible to prevent a protocol that does not conform to the rules from being selected beforehand. An increase in management cost can be suppressed. In other words, if the rules restrict the protocols used on the network, the use of protocols that violate the rules will cause communication failures and increase management costs. Such inconvenience is eliminated by using the above devices in a unified manner. (The above corresponds to claim 2) Moreover, each device 1,
2, 3,..., N have a function to invalidate (down) a protocol that is not specified as a protocol to be used, thereby wasting resources (memory resources and the like) in each device and unnecessary protocols. The processing can be reduced, and unnecessary packet transmission by an unused protocol can be prevented. As a result, the resources of each device are released to reduce the load, and the amount of traffic on the network is reduced to prevent a communication failure and an increase in management cost. However, if communication cannot be performed with the currently used protocol for some reason, there is a possibility that communication will be completely impossible. Therefore, in order to prepare for such a situation, as shown in FIG. 8, the OSI reference models 2 to 3 are used. A layer-level protocol Z is defined, and only packets according to this protocol Z are always kept waiting for reception. The protocol Z is a low-level simple protocol and has a function of reactivating all the protocols of the device that has received the activation command.
(The above corresponds to claim 3)

[0011]

As described above, according to the present invention, the following excellent effects can be exhibited. According to the first aspect of the present invention, in a network system in a multi-protocol environment, each device connected to the network holds parameter information indicating a priority of each characteristic of a protocol that can be used, and when communicating, a device from the partner device transmits the parameter information. The parameter information is obtained and compared with the parameter information of the own device, and the protocol that matches the protocol that can be used by the own device and has a higher priority in the own device is automatically selected for communication. Therefore, it is possible to automatically select an appropriate protocol and perform communication between devices connected via a network without bothering the user. According to the second aspect of the present invention, based on the system configuration of the first aspect, the protocols used in each device and their priorities can be collectively set via a network. In accordance with the above, communication is performed by uniformly and preferentially using higher-priority protocols on a network-by-network basis, preventing the selection of protocols that do not conform to the rules beforehand, and increasing communication failures and responding to them. An increase in management cost can be suppressed. Claim 3
According to the invention described above, on the premise of the system configuration according to claim 2, each of the devices is configured to invalidate a protocol that is not specified as a protocol to be used, so that resources of each device are released to reduce the load. At the same time, it is possible to reduce the amount of traffic on the network and suppress communication failures and increases in management costs.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of a network system showing an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of parameter information indicating a priority order of each characteristic of a protocol supported by each device in FIG. 1;

FIG. 3 is an explanatory diagram of a data hierarchical structure of the network system shown in FIG. 1;

FIG. 4 is an explanatory diagram exemplifying a parameter information acquisition procedure between two devices in FIGS. 1 and 3;

FIG. 5 is a flowchart illustrating the contents of a protocol selection process;

6 is an explanatory diagram showing a command given to each device by a management protocol in FIG. 3 and its specification.

FIG. 7 is an explanatory diagram of an operation of broadcasting a management protocol setting command from one device on the network to all devices.

FIG. 8 is an explanatory diagram of a data hierarchical structure of a network system showing another embodiment of the present invention.

[Explanation of symbols]

 1: device, 2: device, 100: network.

Claims (3)

[Claims] 1. A network system in a multi-protocol environment in which a plurality of devices each capable of selectively using a plurality of types of protocols are interconnected via a network, wherein each of the devices has a protocol which can be used. Holds parameter information indicating the priority of each characteristic, at the time of communication, obtains the parameter information from the partner device and compares it with the parameter information of its own device, matches with a protocol that can be used by its own device, and A network system for automatically selecting a higher-priority protocol in its own device for communication. 2. The network system according to claim 1, wherein a protocol used in each of the devices and a priority order thereof can be collectively set via a network. 3. The network system according to claim 2, wherein each device invalidates a protocol not specified as a protocol to be used.