JPH01165245A - Interrupt packet control system - Google Patents

Abstract

PURPOSE:To prevent traffic on a transmission path from being increased and throughput from being lowered by transmitting an interrupted packet successively after the completion of interruption without deleting the interrupted packet. CONSTITUTION:A nest information attaching part 41 adds nest information representing at least the interruption, the start of the interruption, and the completion of the interruption at the front and the rear of a packet being read out and transmitted from each of transmission buffers (211-21n). A transmission control part 40 indicates the nest information to be attached to the nest information attaching part 41 corresponding to the presence/absence of the storage of the packet in plural transmission buffers (211-21n), and also, the untransmitted part of the interrupted packet is transmitted successively after completing interrupt transmission. In such a way, it is possible to prevent the traffic on the transmision path from being increased and the throughput from being lowered by the re-transmission of a deleted packet.

Description

[Detailed Description of the Invention] [Summary] It is an object of the present invention to provide an interrupt packet control method that prevents an increase in traffic on a transmission path and a decrease in throughput, based on an interrupt packet control method for packet communication with priority. When a high-priority packet is generated while transmitting a low-priority packet, the transmitter performs interrupt transmission of the high-priority packet, and the receiver receives the transmitted packet. a plurality of transmission buffers that separately store packets, and a nest information adding unit that adds nest information indicating at least no interrupt, start of interrupt, and end of interrupt r before and after the packet read from each of the plurality of transmission buffers and transmitted; Transmission control that instructs the nest information to be added to the nest information adding unit depending on whether or not each of the plurality of transmission buffers stores a packet, and continues to transmit the untransmitted portion of the interrupted packet after the interrupt transmission ends. and a plurality of receive buffers for storing packets according to priority, and detecting nest information added to received packets and transmitting the received packets according to the nest information. An interrupt packet control system characterized in that the receiving section includes a nest information detection control section that stores the packet in the receiving buffer of the plurality of receiving buffers and controls readout of the packet from the plurality of receiving buffers.

[Industrial application field]

The present invention relates to an interrupt packet control method, and more particularly, to an interrupt packet control method for packet communication with priority.

FIG. 5 shows a block diagram of a packet switching network. The packet switches N1-N3 are interconnected by transmission paths 10, and data is packetized and communicated between terminals 110 connected to each packet switch N1-N3, respectively.

Inside each of the packet switches Nl to N3, packets are sent to an address/control unit (A) as shown in FIG. 6(A).
/C) 15 and a data section 16, and within the transmission path 10, the packet is marked with a unique flag F17 for identifying the packet and a frame check sequence (Fe2) for detecting transmission errors, as shown in FIG. 1
8 is added.

Packet communication transmits only the actual data in packets, making it possible to effectively use the bandwidth of the transmission path, and erroneous packets can be retransmitted to ensure reliable data transmission, making it widely used for communication between computers and terminals. .

Furthermore, it is expected to become an integrated network that includes audio and images by increasing the exchange speed. In this case, the permissible presence m in the network differs depending on the information handled, so if a high-priority packet occurs while transmitting a low-priority packet, the low-priority packet transmission is stopped and the high-priority packet transmission is allocated. In other words, interrupt packet control is required.

[Conventional technology]

FIGS. 7A and 7B are block diagrams of an example of a conventional interrupt packet control method.

In the transmitting section shown in FIG. 7(A), terminals 20l to 2o
Packets that have been switched for each of the n levels of priority arrive at each of the transmission buffers 21l to 21η, respectively. The transmission control unit 22 has transmission buffers 21l to 2
Selector 23 determines the presence or absence of packet 1n and its priority.
A packet from one of the transmission buffers is selected by the selector 23 and output. After the FC3 generation section 24 generates and adds Fe2 to this packet, the data conversion section 25 performs conversion to make the flag F unique, and the flag addition section 26 adds a 7 lag F. The packet passes through the driver 27 to the terminal. 28 to the transmission line.

In addition, in the receiving section shown in FIG. 2(B), a packet that comes in from the transmission path via the terminal is received by the receiver, flag F is deleted by the flag detection and deletion section 32, and data is converted by the data inverse conversion section 33. The signal is subjected to inverse transformation to the conversion performed by the unit 25 and is supplied to the FC8 verification unit 34. The FC8 verification unit 34 performs error detection using Fe2, and if there is an error, discards the packet. Packets without errors are stored in the reception buffer 35 and supplied from the terminal 36 to the next stage circuit which performs switch exchange based on priority.

[Problem that the invention seeks to solve]

In the conventional method, when a packet with a higher priority occurs during transmission of a packet, the transmission control unit 22 stops transmitting the packet currently being transmitted, discards the data remaining in the transmission buffer, and generates the FC3C3 generation 4 and flag. The adding unit 26 is reset and transmission of high priority packets is started.

Furthermore, in the receiving section, packets whose transmission has been stopped due to the FC8 check are discarded.

Therefore, while high-priority packets are transmitted with low delay, lower-priority packets have a higher probability of being discarded, and retransmission of discarded packets increases traffic on the transmission path and reduces throughput. There was a point.

The present invention has been made in view of the above points, and an object of the present invention is to provide an interrupt packet control method that prevents an increase in traffic on a transmission line and a decrease in throughput.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the system of the present invention.

In the figure, a plurality of transmission buffers 721l to 21n store packets coming from terminals 20l to 20n according to priority.

The nest information adding unit 41 adds nest information indicating at least no interrupt, start of interrupt, and end of interrupt before and after each packet read from each of the transmission buffers 21l to 21n and transmitted.

The transmission control unit 40 instructs the nest information adding unit 41 to add nest information depending on whether or not packets are stored in each of the plurality of transmission buffers 21l to 21n, and also instructs the untransmitted portion of the interrupted packet after the end of the interrupt transmission. continue to be transmitted.

The packet to which the nest information has been added is sent to the transmitter body 60 by F.
C3 generation, data conversion, and flag addition are performed, and the signal is sent to the transmission path 61.

The flag detection and deletion unit 32 of the reception unit detects and deletes the flag added to the packet.

The plurality of reception buffers 52l to 521 store packets according to priority.

The nest information detection control unit 50 detects nest information added to a received packet, stores the received packet in a plurality of reception buffers 52l to 521 according to the nest information, and stores the received packet in a plurality of reception buffers 752l to 521. 52n.

The packets read from the reception buffers 52l to 52n are subjected to data inverse conversion and FC3 verification in the reception section main body 62.

[Effect]

In the present invention, the interrupted packet is not discarded, but continues to be transmitted after the interruption ends.

This reduces the frequency of packet retransmission, thereby preventing an increase in communication network traffic and a decrease in throughput.

〔Example〕

FIGS. 2(A) and 2(B) show block diagrams of an embodiment of the transmitter and receiver of the interrupt packet control system of the present invention. In the figure, the same parts as in FIGS. 7(A) and 7(B) are designated by the same reference numerals, and their explanations will be omitted.

In FIG. 2(A), the transmission control unit 40 determines the presence or absence of packets in the transmission buffers 21l to 211 and selects the selector 23.
In addition to sterilizing the switching, it also performs nest control. The packet (A/C 15 and data section 16) output from the selector 23 is supplied to the nest information addition section 41, where the third
As shown in Figure (A), nest information 19 is added before <A/C 15. This nest information is 2-bit information added according to the nest control of the selector 40, for example, “00
” is Butshu, “01” is Pull, “10” is Nan, “
11" represents the top. If there is no interrupt, a number is added after the flag F at the beginning and end of the packet, and when an interrupt is performed, a bush indicating the start of the interrupt is added after the flag F at the beginning of the packet. A pull indicating the end of the interrupt is added after the end flag F. Also, when interrupting a packet with the highest priority, a top is added instead of a bush. Note that the top does not have to be used.

For the packet to which the nest information has been added, the FC8 generation unit 24 generates Fe2 for the A/C 15, data section 16, and nest information 19, and adds FC318 after the data section 16 as shown in FIG. 3(A). . Also, when the nest control represents a bush or top, the Fe currently being calculated is
The intermediate result of Fe2 is saved in the memory 43, and when a pull is indicated, the intermediate result of Fe2 that is saved in the memory 43 is read out and the calculation is continued. The output of the FC8 generator 42 is supplied to the data converter 25.

When an interrupt occurs due to this, the format of the packet sent from the terminal 28 to the transmission line is as shown in FIG. 3(B). In the figure, a portion 44 is the first half of a low-priority packet, a portion 45 is a high-priority packet to be transmitted with an interrupt, and a portion 46 is the second half of a low-priority packet following the portion 44.

In FIG. 2(B), the nest information detection section 50 reads the nest information following the flag F and supplies the remaining A/C 15, data section 16, and FC 818 to the selector 51, and also operates the selector 51 according to this nest information. Switch. As a result, non-interrupt packets are sent to the receive buffer 5.
21, and the interrupt packet for this packet is stored in the receive buffer? 522. Receiving buffer? are provided with n numbers 52l to 52n, which is the same as the number of priority levels, and the reception buffer ? Interrupt packets for interrupt packets stored in the receive buffer 522
Next receive buffer? is stored in

Further, the selector 53 to which the output of each of the receive buffers 52l to 52n is supplied is controlled by the nest information, and selects the output of the receive buffer 52+ if there is no interrupt, and selects the output of any of the receive buffers 7522 to 52n if there is an interrupt. The output is selected and supplied to the data inverse conversion section 33.

As a result, as shown in FIG. 3, when a packet with a low priority NJ is transmitted (period n a ), a packet with a higher priority "2" is transmitted interruptively, and furthermore, at the time of this transmission, a packet with a higher priority "i" is transmitted. When a packet with a priority of "3" is transmitted as an interrupt, as shown in FIG.
The transmission ends in the period T2b following
When the transmission of the packet ends in the period T4, the transmission of the packet with priority "1" ends in the period Tub following the period Tea.

In this case, is the packet with the highest priority "3" in the receive buffer? Since there is no delay due to buffering in any one of 52l to 52n, the delay can be minimized.

In this way, the interrupted packets are held in the receive buffers 52l to 52n without being discarded, and the remaining portion is transmitted after the interrupt is completed, reducing the frequency of packet retransmission, reducing the increase in traffic on the transmission path and reducing throughput. This prevents a decrease in

〔Effect of the invention〕

As described above, the interrupt packet control method of the present invention prevents an increase in transmission line traffic and a decrease in throughput, and is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the method of the present invention, Fig. 2 is a block diagram of an embodiment of the method of the present invention, Fig. 3 is a diagram showing the packet format of the method of the present invention, and Fig. 4 is a diagram of the method of the present invention. FIG. 5 is a diagram illustrating the configuration of a packet switching network; FIG. 6 is a diagram showing the packet format of a conventional system; and FIG. 7 is a block diagram of an example of the conventional system. In the figure, 21l to 21n are transmission buffers 23, 51, and 53 are selectors, 25 is a data conversion unit, 26 is a flag addition unit, 32 is a flag detection deletion unit, 33 is a data inverse conversion unit, 34 is an FC8 verification unit, 35 .52l to 521 are reception buffers, 40 is a transmission control unit, 41 is a nest information addition unit, 42 is an FC3 generation unit, 43 is a memory, and 50 is a nest information detection unit. Zuka 1t! 1 (A) Wood shavings≦Ashimon wo ibeme format 8 Yasoji re 3 figures attendance 9 female Ya 6〉 enemy Riu, Shi 1 Dai, Toku, left ga mimi T flea member Pedetop ζ Captive 19 Tsukasa/) Introduction ℃d @ 5 Figures

Claims (1)

[Claims] An interrupt packet in which, when a high-priority packet is generated during transmission of a low-priority packet, the transmitter performs interrupt transmission of the high-priority packet, and the receiver receives the transmitted packet. In the control method, multiple transmit buffers (2
1_l to 21_n) and the plurality of transmission buffers (21_l to 21_n) before and after each packet read and transmitted, a nest information adding unit (41) that adds nest information indicating at least no interruption, start of interruption, and end of interruption; and instructs the nest information to be added to the nest information addition unit (41) according to whether or not packets are stored in each of the plurality of transmission buffers (21_l to 21_n), and also indicates the uninterrupted packets after the interrupt transmission ends. The transmitting unit includes a transmitting control unit (40) that causes the transmission part to be continuously transmitted, and a plurality of receiving buffers (50) that store packets according to priority.
2_l to 52_n), detects nest information added to the received packet, stores the received packet in the plurality of reception buffers (52_l to 52_n) according to the nest information, and stores the received packet in the plurality of reception buffers (52_l to 52_n); a nest information detection control unit (
50) in the receiving section.