JP2916185B2 - Dynamic selection method of incoming communication adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a method for dynamically selecting an incoming call communication adapter used for LAN communication (Local Area Network), and in particular, to a plurality of communication methods. In a LAN system where nodes with adapters (ie multiple physical addresses) exist in the system,
The physical address of the incoming communication adapter has not been determined,
For transmission of a name inquiry frame by simultaneous broadcast from the calling node to all other nodes, a preferred called communication adapter used when obtaining the physical address of the called node's communication adapter from the response frame. Dynamic selection method.

(Prior art) Conventionally, in a LAN system, when the processing software of a calling node does not know the physical address of a called node, a name inquiry frame is transmitted to all nodes by a broadcast frame. However, there is a method of obtaining the physical address of the called node in the corresponding frame.

However, this method does not allow multiple nodes having the same name, and as shown in FIG.
Only applicable in small LAN systems.
In FIG. 3, reference numeral 31 denotes a personal computer as a server station, 32A, 32B,..., Personal computers as client stations, and 33, a LAN communication path. Reference numeral 301 denotes a name inquiry frame by broadcast from the calling node (personal computer 32A), and reference numeral 302 denotes a response frame for notifying a physical address from the corresponding called node (personal computer 31).

(Problems to be Solved by the Invention) As described above, the conventional method does not allow a plurality of nodes having the same name to exist, and in a small-scale LAN system as shown in FIG. Although it was applicable, when one node has a plurality of communication adapters (that is, a plurality of physical addresses) like a large computer, a plurality of response frames are generated in the above-described conventional method. There is no standard on whether to use the physical address of
There was a problem in system operation.

The present invention has been made in view of the above circumstances, and even if the called node accommodates a plurality of communication adapters in order to improve processing efficiency, the calling node can determine the optimum It is an object of the present invention to provide a method for dynamically selecting a called communication adapter capable of determining a suitable communication adapter.

[Configuration of the Invention] (Means and Actions for Solving the Problems) According to the present invention, at least one node having a plurality of communication adapters is provided, and a caller node sends a name inquiry frame by simultaneous broadcast in a system. In a LAN system transmitting to all nodes and obtaining a physical address of a communication adapter of the called node based on a response frame output from the called node in response to the name inquiry frame, the calling node includes: When a plurality of response frames are received from a node having the plurality of communication adapters in response to the output name inquiry frame, the plurality of communication adapters are determined based on status values of the received plurality of response frames. In this configuration, the target communication adapter is selected from the nodes that have Be configured accommodating the signal adapter, can select what in calling node side to the optimal state of the communication adapter having a plurality to the called node side, it is possible to improve system throughput by optimizing the load distribution.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

 FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a CPU which controls the processing of a large computer, and 2 denotes a communication control device (hereinafter referred to as FEP) which forms a front-end processor of the large computer. 2A, 2B, 2C are each under the control of FEP2, each equipped with a microprocessor and an independent channel (communication adapter)
Communication processors (CP1, CP2, CP3)
A communication process is performed with the communication path 4 to process a lower layer protocol. 3A and 3B are personal computers connected to the LAN 4, respectively, for transmitting and receiving data to and from the large computer via the LAN 4. Reference numeral 4 denotes the large computer and personal computers 3A and 3B serving as communication terminals.
This is a LAN that forms a communication path used for data transmission between the LAN. Reference numeral 11 denotes a command frame (name inquiry frame) for name inquiry by simultaneous broadcast. Here, the case where the personal computer 3A becomes the calling node (client) and sends out the command frame 11 for name inquiry. An example is shown. Reference numeral 12 denotes a response frame (physical address notification frame) from the corresponding node to the command frame 11 for the name inquiry. FIG. 3 illustrates a case where response frames 12a, 12b, and 12c for notifying a physical address are transmitted to the host.

FIG. 2 is a diagram showing the contents of a response frame to the name inquiry frame 11. In the figure, reference numeral 121 denotes a destination address (DA), and reference numeral 122 denotes a source address (SA). Reference numeral 123 denotes a status (status 1) indicating the number of currently established connections of the local communication adapter, reference 124 denotes a status (status 2) indicating the current free buffer memory capacity of the local communication adapter, and reference numeral 125 denotes a status of the local communication adapter. Status (status 3) indicating the speed of the microprocessor, 126 is another status having an index value other than the above.

Here, the operation in one embodiment of the present invention will be described with reference to FIG. 1 and FIG.

The personal computer 3A transmits a command frame 11 for name inquiry by simultaneous broadcast to the LAN 4. The command frame 11 transmitted from the personal computer 34 serving as the calling node is received by all communication nodes on the LAN 4.

When each of the communication processors 2A, 2B, and 2C of the large computer receives the command frame 11 of the name inquiry by simultaneous broadcast from the personal computer 3A, each of the communication processors 2A, 2B, and 2C matches the inquiry name. , 2C return the response frames 12a, 12b, 12c of the physical address notification, respectively. At this time, the response frames 12a, 12b, 12c transmitted from the respective communication processors 2A, 2B, 2C have different contents. FIG. 2 shows a configuration example of the response frames 12a, 12b, and 12c. Here, in each of the above response frames 12a, 12b, 12c,
In addition to the destination station address (DA; Destination Address) 121 and the own station address (SA; Source Address) 122, as the status, a status 123 (status 1) indicating the number of currently established connections of the own station communication adapter; There are indicators of status 124 (status 2) indicating the current free buffer memory capacity of the own communication adapter and status 125 (status 3) indicating the speed of the microprocessor of the own communication adapter.

The personal computer 3A serving as the calling node compares the status values of the plurality of received response frames 12a, 12b, and 12c, and selects an optimum called node (communication processor) at that time.

Here, the optimal called node is, for example, one having a small number of connections being established, one having a large free buffer capacity,
The fastest microprocessors are available.

In this way, the calling node (here, the personal computer 3A) is connected to the optimal called node (communication processor).
Is selected, a communication connection is established by designating the communication adapter.

Thus, the command frame (1
When multiple response frames (12a, 12b, 12c) exist for 1), a specific status value (12
Target communication adapter (communication processor 2A, 2
B, 2C), even if the called node accommodates multiple communication adapters, even if the called node has multiple communication adapters on the called node side Can be selected, and the system throughput can be improved by optimizing the load distribution.

The method according to the above embodiment is effective when the called communication adapter controls a certain communication protocol.
Further, when all communication protocols are performed by the main body side instead of the microprocessor of the communication adapter, a great effect cannot be expected. In such a case, a plurality of communication adapters should not be accommodated.

In the embodiment described above, index values such as the number of currently established connections of the local communication adapter, the current free buffer memory capacity of the local communication adapter, and the speed of the microprocessor of the local communication adapter are used. Although the selection conditions,
The present invention is not limited to this, and statuses having other index values, etc. may be used as selection conditions, or statuses based on only a part of the above index values, or a combination of some of the above index values with other index values, etc. Etc. may be used as the selection condition.

[Effects of the Invention] As described in detail above, according to the method for dynamically selecting a called communication adapter according to the present invention, at least one node having a plurality of communication adapters is provided, and a name is simultaneously broadcast from a calling node. In a LAN system, an inquiry frame is transmitted to all nodes in the system, and a physical address of a communication adapter of the called node is obtained based on a response frame output from the called node in response to the name inquiry frame. When the calling node receives a plurality of response frames from the node having the plurality of communication adapters in response to the output name inquiry frame, based on status values of the plurality of received response frames, By selecting the target communication adapter from the nodes having the plurality of communication adapters, the Even in a configuration that accommodates a number of communication adapters, the calling node side can select the communication adapter that is in the optimum state with multiple communication adapters on the called node side, and improves system throughput by optimizing load distribution it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing the structure of a response frame in the above embodiment, FIG.
FIG. 1 is a diagram showing a system configuration for explaining a conventional means for obtaining a physical address of a called node. 1 ... CPU of large computer, 2 ... Communication control device (FEP) which forms front-end processor of large computer, 2A, 2B, 2
C: Communication processor (communication adapter; CP1, CP2, CP3), 3
A, 3B personal computer, 4 LAN (communication path), 11 command frame (name inquiry frame), 12 response frame (physical address notification frame), 12a, 12b, 12c physical address Notification response frame, 121: Destination address (DA)
s), 122 ... Local station address (SA; Source Address), 123
... Status (status 1) indicating the number of currently established connections of the own station communication adapter, 124... Status (status 2) indicating the current free buffer memory capacity of the own station communication adapter, 125. Status (Status 3) indicating the speed of the microprocessor of the adapter.

Claims (2)

(57) [Claims] At least one node having a plurality of communication adapters is provided, and a calling node transmits a name inquiry frame by broadcast to all nodes in the system, and responds to the name inquiry frame. In a LAN system for obtaining a physical address of a communication adapter of a called node based on a response frame output from the called node, the calling node responds to the output of the plurality of communications in response to the output name inquiry frame. Upon receiving a plurality of response frames from the node having the adapter, selecting a target communication adapter from the nodes having the plurality of communication adapters based on status values of the plurality of received response frames. Dynamic selection method of incoming call communication adapter to perform. 2. The system according to claim 1, wherein the status value includes at least one of a number of currently established connections, a currently available buffer capacity, and a processor processing speed of a communication adapter. (1) A method for dynamically selecting an incoming call communication adapter according to (1).