JP2789657B2 - Communications system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding a network address management process provided for communication management in a communication system, the possibility of address assignment is improved by efficiently utilizing the address capacity of a network address having a fixed bit length. For the purpose of a communication system that can be expanded, a plurality of computers are connected via a network, and resources managed by each computer are specified by a network address composed of a sub-area address identified by the computer and an element address identifying the resource. In communication systems,
A subarea address management table for managing a subarea address for a computer and a pointer to an element address table in which an element address is registered for each subarea, and a subarea address management table when registration of a network address is designated. A search is performed to determine whether registration is possible in the element address table. If registration is not possible, a new subarea address and a network management unit that registers the corresponding element address table in the subarea address management table are configured.

[Industrial applications]

The present invention relates to a communication system provided for communication control in a communication system.

[Problems to be solved by conventional technology and invention]

FIG. 3 (a) is a block diagram showing the configuration of a communication system, in which a host computer 1 and a host computer 2 are connected by a communication path connecting respective communication control processors (CCPs) 3 and 4 to form a network. It is an example of a subnetwork constituting a part.

Each host computer 1 of such a subnetwork,
2 and each CCP3, 4 as one sub area,
For each of these subareas, each terminal device 5 and each application program 6 executed in the host computer are managed as elements in the subarea, and a subarea address (SA) for identifying the subarea, Network address (N) consisting of element addresses (EA) in the area
A) to uniquely identify the elements within the sub-network.

That is, as illustrated in the figure, SA =
1. SA = 2 for host computer 2, SA = 3 for CCP3, SA for CCP4
= 4 to identify each sub-area, and then assign EA = 1 and 2 to the application programs executed on the host computer 1, they are identified by NA = 11,12, and so on.

The network address assigned in this way is
In the communication between the elements, the information is inserted into a predetermined position of the communication information and transmitted, and is used as information indicating a source and a destination of the communication, thereby being used for communication routing control and the like.

For this purpose, the network address is represented in a fixed length format of 16 bits as shown in FIG. 4, for example.
The remaining lower bit strings are used for element addresses. Note that “0” is excluded from the sub-area address from the control case. Therefore, by using m bits, 2 ^m −1
In the example of FIG. 3A, a sub-area address having a length of at least 3 bits is necessary. In this case, 4 out of 7 sub-areas can be identified.
Addresses have been used.

Each network management unit 12 provided in the host computer, etc.
5 has a sub-area address management table 10 as shown in FIG. 5, and in each item derived from the sub-area address management table 10 using the sub-area address as an offset, the relevant sub-area address is its own address or another sub-address. A flag column indicating whether the address is an area address and routing information include:
It has a path column and the like indicating a subarea address of an adjacent subarea constituting a path to the subarea.

The contents of each column are separately initialized in accordance with, for example, an address and path information designated by a system operator or the like, and only one item corresponding to the sub-area address assigned to the sub-area is set in the flag column, for example, “1”. And all other items are set to “0” to indicate their own subarea addresses. In the path column of each item, the subarea address of an adjacent subarea according to the path information is set. When the path field is "0", it indicates an unassigned address.

Also, an element address table 11 is provided, and for each item to be pulled using the element address as an offset, the device address of the element, the address of the access queue, and the like as routing control information necessary for accessing the element to which the element address is assigned. Keep others.

The network management unit 12 changes the network address of the element when the activation processing for making the terminal device under management operable or the processing of a session opening request with another element by the application program is requested. To determine and return to the requestor, for example,
In the processing step 20 of FIG. 7A, the item of the own sub-area is detected from the flag column of the sub-area address management table 10 at the predetermined address, and the sub-area address is determined by the offset value addressing the item.

Next, if the element address table 11 is searched in the processing step 21 and an empty item (for example, all 1s) is detected, the routing control information for the element to which the assignment is made is set in the item in the processing step 22. The element address is obtained from the offset value of the term, and the network address determined in processing step 23 is returned to the request source. If there is no vacancy, the process branches to processing step 24 to notify that allocation is not possible, and the requester appropriately handles it.

In the routing processing, the processing steps shown in FIG.
The subarea address management table 10 is read with the subarea address of the network address designated by the request source as an offset in 31. If the flag is 0, processing steps 32 to 33 are executed.
If the path column is not 0, the contents are passed to the request source as the adjacent subarea address in the processing step 34.
If the content is "0", the network address is incorrect, and an error is notified in processing step 35.

If the flag is "1", the element address table 11 is read in the processing step 36, it is checked that it is not allocated in the processing step 37, and if it is allocated, the routing control information is passed in the processing step 38, and if it is not allocated, the processing is performed. In step 39, an error is notified.

The network address is local to each subnetwork obtained by appropriately dividing the entire network, and the number of bits of the subarea address is determined in consideration of the number of subareas in the subnetwork and the maximum number of elements in one subarea. If the element addresses in the subarea are insufficient, for example, the subnetwork must be reduced to reduce the subarea.

However, element addresses are rarely uniformly lacking in all sub-areas, and are often biased to specific sub-areas. In this case, the element address becomes too large, and the capacity of the network address cannot be used effectively, resulting in an increase in the number of subnetworks.

An object of the present invention is to provide a communication system capable of efficiently using the address capacity of a network address having a fixed bit length and expanding the possibility of address allocation.

[Means for solving the problem]

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

The figure shows the configuration of a communication system, in which a plurality of computers are connected via a network, and resources managed by each computer are specified by a network address consisting of a subarea address identified by the computer and an element address identifying the resource. In the communication system, when a subarea address for a computer, and a pointer to an element address table 41 in which an element address is registered, a subarea address management table 40 for managing each subarea, and registration of a network address are designated, The sub-area address management table 40 is searched to determine whether registration is possible in the element address table 41. If registration is not possible, a new sub-area address and a corresponding element address table 41 are registered in the sub-area address management table 40. Network Management Department
And 42.

(Operation)

With the communication system described above, in order to cover the element address capacity required in a specific sub-area, it is not necessary to shorten the sub-area address and unnecessarily increase the capacity of the element addresses of all other sub-areas. By setting sub-area addresses and element addresses of appropriate capacity, and assigning a plurality of sub-area addresses to sub-areas requiring a large number of element addresses in particular, the element address capacity can be increased. Address capacity can be used efficiently.

〔Example〕

In FIG. 1, a sub-area address management table 40 includes a flag indicating whether the relevant sub-area address is its own address or an address of another sub-area, for example, as in the conventional case, for each item pulled with the sub-area address as an offset. And a path column indicating the sub-area address of an adjacent sub-area constituting a path to the sub-area, and a pointer column as routing information.

The pointer column is valid only for the item assigned to the own sub-area, and sets a pointer to point to an element address table 41 indicating an element address in the sub-area corresponding to the item.

The network management unit 42 determines the network address of the element and returns it to the request source when the activation processing of the terminal device under management or the processing of the session opening request by the application program is requested. 2 When a term of its own sub-area is detected by a flag column of the sub-area address management table 40 at a predetermined address in a processing step 50 of FIG. 5A, a sub-area address determined by an offset value of the term is detected in a processing step 51. Then, in the processing step 52, the element address table 41 designated by the pointer column of the item is searched.

If a vacant term is detected, the routing control information for the element to which the assignment is made is set in the term in the processing step 53, and the element address is obtained from the offset value of the term, and is combined with the subarea address stored in the processing step. The network address determined in this way is returned to the request source.

If there is no free space in the element address table in the processing step 52, the process returns to the processing step 50, scanning from the next item of the sub-area address management table 40, searching for the item of the own sub-area, and finding the corresponding item. If so, the process proceeds to processing step 51.

In this way, if there is no vacant element address even if processing is performed for all subarea addresses assigned to the own subarea, after processing the last applicable item and returning to processing step 50, Processing Step 55
To notify that the network address cannot be allocated.

In the case of the routing processing, the processing is performed as shown in the processing flow of FIG. Processing steps 61 to 61 of this processing
Step 65 is the same as the processing steps 31 to 35 of the conventional processing described with reference to FIG. Processing steps 66-69
Is the same as the conventional processing steps 36 to 39, except that when accessing the element address table in the processing steps 66 and 68, the element address table 41 indicated in the pointer column of the sub area address table 40 is accessed. .

According to the above processing method, in the example of FIG. 3A, for example, when the element address is insufficient in the sub-area of the host computer 2, as shown in FIG. 2 as subarea address
In addition to the sub-area address 5, which has not been used before,
The addresses 6 and 7 can be allocated to supplement the address capacity, and the element address capacity of the sub-area of the host computer 2 can be increased up to four times the conventional value.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, there is a remarkable industrial effect that a communication system can efficiently utilize the address capacity of a network address having a fixed bit length to expand the possibility of address allocation.

[Brief description of the drawings]

 FIG. 1 is a block diagram showing a configuration of the present invention, FIG. 2 is a flowchart of a process of the present invention, FIG. 3 is a diagram showing a configuration example of a network, FIG. FIG. 1 is a block diagram showing a conventional configuration example, and FIG. 6 is a flowchart of a conventional process. In the figure, 1 and 2 are host computers, 3 and 4 are CCPs, 10 and 40 are subarea address management tables, 11 and 41 are element address tables, 12 and 42 are network management units, 20 to 24, 31 to 39, 50 to 55 and 61 to 69 indicate processing steps.

Claims (1)

(57) [Claims] A plurality of computers are connected via a network, and resources managed by each computer are assigned to a sub-area address which is an identifier set for each computer and an element address which is an identifier set for each resource. In a communication system specified by a network address consisting of: a flag indicating that the subarea address is in use for all subarea addresses, and a pointer to an element address table in which corresponding element addresses are registered When the registration of the sub-area address management table and the network address is specified, the sub-area address management table is searched, and it is determined whether or not the element can be registered in the element address table. Search and set the busy flag for the corresponding subarea address Communication system comprising a network management unit for registering a pointer to Rutotomoni element addresses table in the sub-area address management table, in that they are composed of.