JPS63287231A - Keeping system for real time property in inter-network connection device - Google Patents

Abstract

PURPOSE:To keep the real time property of a data such as voice requested, the real time characteristic of data by processing a received data of a specific length with priority. CONSTITUTION:The reception data with a specific data length only is processed with priority in an inter-network connection device. The specific reception data length is plural figures depending on a communication network receiving the data. The figures are initialized after the expanded communication network being the plural communication networks subject to inter-network connection by the internetwork connector is initialized and revised when the logical constitution of the expanded communication network is revised. That is, a priority data length registration memory 14, a priority data buffer 15 and a nonpriority data buffer 16 are connected to an internal bus 13. Thus, the real time property of the data is preserved by applying priority processing in the inter-network connector to only the data having a specific data length.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an extended communication network system constructed by interconnecting a plurality of communication networks,
In particular, it relates to an extended communication network system in which data that requires real-time performance, such as voice, and other data coexist.

[Conventional technology]

Recently, attention has begun to be paid to maintaining real-time performance in inter-network connection devices. As a main method, for example, Japanese Patent Application Laid-Open No. 61-177049 can be cited. This method focuses on the fact that the length of data that requires real-time performance is often short, such as audio data. Specifically, by processing received data in the order of length in the network interconnection equipment, data that requires real-time performance and is characterized by short data length can coexist with other data. This system maintains real-time performance in inter-network connection devices in communication network systems.

[Problem that the invention seeks to solve]

In the system prior to the above-mentioned prior art, the network connection equipment determines whether data passing through the network connection equipment requires real-time performance or not, based on recognition codes added to the data. Packets that require real-time performance are processed preferentially by being identified within the connecting device. Therefore, it is necessary for the data to have a recognition code to indicate whether real-time performance is required, and the transmitting station must add the recognition code to the data, and the inter-network connection device must also understand the internal structure of the data. must have knowledge of Furthermore, in the case of a protocol that has already become an international standard, it is also a violation of the protocol.

On the other hand, the above-mentioned Japanese Patent Laid-Open No. 61-177 allows the real-time nature of data to be maintained without being aware of the data contents.
This is the superiority of 049.

However, this method also has the following problems.

(1) It is true that data that requires real-time performance, such as audio data, has a higher probability of having a shorter data length than other data. However, among the long data transmitted by stations, there is also data that requires real-time performance. Furthermore, when data passes through a network with a long allowable maximum data length, the data is segmented and processed into shorter data. For the above reasons, it can be understood that short data does not necessarily require real-time performance. Therefore, there are many problems with simply processing data in the order of shortest data.
Due to the length of the bytes, there may be highly real-time data that cannot pass through the inter-network processing device.

(2) If segmentation occurs, the data length of the last segment is less than or equal to the data length of other segments. Therefore, if there are other segments in the buffer, a network connection device that does not look at the data content will process the last segment before the other segments, resulting in the segments not being in the correct order. Put it away. As a result, this data is destroyed at the interconnection device that reassembles the segments or at the receiving station.

[Means for solving problems]

The present invention solves the above problem by preferentially processing received data only when it has a certain data length in an inter-network connection device. Here, the specific reception data length is
Multiple numbers depending on the communication network that received the data. These values are initialized after the initialization of an extended communication network in which multiple communication networks are interconnected by an inter-network connection device, and updated when the logical configuration of the extended communication box 1 to work is changed. .

[Effect]

Data that requires real-time performance is often of a specific length, such as audio data. The main body of the audio data is, for example, 64 bytes, and the total data length is the length of this plus a head and trailer specific to each communication network. Therefore, the real-time nature of data is preserved by subjecting only data having a specific data length to preferential processing in the network connection device.

Additionally, if the transmitting station is aware of the minimum value of the maximum data length in each communication network of the extended communication network, the transmitting station will adjust the data segment length to prevent segmentation from occurring on the way. Often sent. In this case, by setting the segment lengths of priority data and non-priority data to different values, the former can be transmitted preferentially.

In a connection-based transmission method in which delivery confirmation is performed for one or more data transmissions even when the length of the last segment does not match the segment length, the transmission confirmation cycle is shortened by the present invention. Even if the last segment is not prioritized, the delay experienced by the entire data is reduced.

If this method is used, the following two problems in JP-A-61-177049 will not occur.

(1) The problem of losing real-time performance of data that requires real-time performance due to priority processing of data that does not require real-time performance does not occur with this method, which prioritizes processing of only data with a specific data length. .

(2) The problem of abnormal segments of segmented data occurs only when the final segment length coincidentally matches the priority data length, since data with short data lengths are not prioritized in this method.

As a way to prevent this coincidence, for example, in an inter-network connection device that performs segmentation, it is possible to pad the data length of the final segment so that the data length is no longer the priority data length. For example, it is only necessary to make the final segment length match the other segment lengths. In this case, if the segment length of the core communication network is made the priority data length, the following secondary effect can also be obtained. Data passing through multiple interconnect devices often passes through a backbone communication network, and these data are segmented into segment lengths of this communication network. As a result, data passing through multiple communication networks is processed preferentially, reducing delays in these data.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows the network connection between LANI and LAN2 by the network connection device φ. The network connection device φ can access L A N 1 (2) using the LAN adapter 3 (4). CPU6 operates according to the code in ROM5
After completing the protocol conversion of the data in the receive buffer 9 (10) on the shared memory 7 (8) with the LAN 1 (2), the data is transferred on the shared memory 8 (7) with the LAN adapter 4 (3). The data is registered in the transmission buffer 12 (11).

In order to maintain real-time data, internal bus 1
3 has three memories, that is, priority data □ length registration memory 14. Priority data buffer 15. Non-priority data buffer 16. Connect. These three memories and shared memory 7
．． 8 need only be logically distinct, and may be physically located on a shared memory between the CPU 6 and the LAN adapters 3 and 4, for example.

Priority data length: An algorithm for preferentially processing data registered in the registration buffer 14 is shown in FIG.

When receiving an interrupt from LAN adapter 3 (4), [2
0], determine whether data processing is being performed on the priority or non-priority buffer 15-16 [211. If it is not running, receive buffer 9 on LAN adapter 3 (4) (
10), the data is transferred to LAN adapter 4 (
3) Transfer to the upper sending buffer 12 (11).

If data is being processed [21], data processing on the data buffer is suspended [23].

When processing non-priority data, determine whether the received data length is registered in the priority data length registration memory 14 [24]
, if it is registered, [LA
After data processing is completed by N adapter 3 [4], the data is transferred to LAN adapter 4 [3].

In other cases [24], a suitable data buffer 15
Or register on 16 [26].

After completion of [25] or [26], data processing in the data buffer 15 or 16 is restarted [27].

〔Effect of the invention〕

According to the present invention, since data of a specific data length can be processed preferentially in an inter-network connection device, there is an effect that real-time performance is not impaired even if real-time data passes through a plurality of inter-network connection devices. In this method, the transmitting and receiving stations do not need to be aware that priority processing is being performed by the network connection device, and there is no violation of standardized protocols.

In addition to this, the following two problems of Japanese Patent Application Laid-Open No. 177049/1988 are solved.

(1) Since the data length of the data to be processed with priority is clearly specified, there is little possibility that data that does not need to be processed with priority will be processed with priority.

(2) For the same reason, the order of segmented data cannot be targeted. As a result, the probability of retransmission becomes low.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of an inter-network connection device;
FIG. 2 is an algorithm diagram executed by the CPU 6. φ...Network connection device, 1, 2...LAN, 3, 4...
・LAN adapter, 5...ROM, 6...CPU,
7゜8...Shared memory, 9,10...Reception buffer, 11゜12...Transmission buffer, 13...Internal bus, 14...Priority data length Wta memory, 15...Priority data Buff figure 2

Claims (1)

[Claims] 1. a plurality of input/output devices that transmit data to a communication network and receive data from the communication network;
a memory for accumulating received data and searching said data;
In an inter-network connection device comprising means for determining a destination network to which the received data is to be transmitted, and a processor for converting the received data in order to transmit the received data to the destination network, the received data is If the length of the received data is not the order in which the output device receives the received data, but is one of the data lengths registered as data lengths to be processed with priority at the time of receiving the received data, , by processing the received data preferentially in the processor and transmitting it to the destination network, in the case of data of a specific length, the delay that the data of the specific length suffers at the network connection device is reduced. This makes it possible to maintain the real-time nature of data such as voice, which requires real-time performance, in an extended communication network constructed by interconnecting multiple communication networks using the inter-network connection device, etc. A method for maintaining real-time performance in an inter-network connection device characterized by: