JPS5870659A - Data communication system - Google Patents

Abstract

PURPOSE:To limit packet flow to a network, by giving an access with different priority to packet transmission of virtual call type. CONSTITUTION:A packet data incoming to a network transmitter and receiver 2 from a terminal device 1 is discriminated for whether a call set request packet or other packets at a discriminating means 21. In case of the call set packet, a timer of a call set abolishing means 23 is started, the packet and information to be discriminated are given to a priority attaching means 22, where a low priority is given and the packet is transmitted to a data communication network 3, and packets other than the call set request packet are given with a high priority at the means 22 and transmitted to the network 3. The packet received from the network 3 are discriminated their classification at a discriminating means 24. In case of the call request packet, a response packet is made at a response packet forming means 25, a low priority is provided at the means 22 and transmitted to the network 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for transmitting data with priority in a data communication network capable of transmitting packetized data.
data transmitted through & nodes to enable communication between predetermined terminals, and as shown in Figure 2, the data transmitted from the terminals is transmitted via a degenerate receiving device. There are some types of media that are accessed in such a way that collisions do not occur. (bucket in the net shown in Figure j11)
d is accumulated at each node and sequentially passed to other nodes.

Therefore, if a large amount of data comes in from each terminal almost simultaneously, each node will have to wait, resulting in a disadvantage that the overall transmission delay will increase. Further, in the network shown in FIG. 2, some kind of control method must be used so that packets can be accessed without collisions on the medium. Therefore, in this case, if a large amount of data comes in from the terminal at the same time,
This method has the disadvantage that each degenerate receiving device waits for access, resulting in a large transmission delay.

The purpose of the present invention is to differentiate between call setup and normal data transmission in virtual call type packet transmission in which packets are transmitted by configuring one logical channel by attaching a series of codes to a plurality of consecutive packets. By transmitting the data with priority, and by making it possible to set up and especially abandon calls, it is possible to limit the flow of data flowing into the network and to transmit data without causing large transmission delays during normal data transmission. .

The goal is to realize a data communication system that

In packet transmission using virtual fools, call setup is performed to establish a logical channel between a transmitting station and a receiving station when transmitting a series of packets. Normally, when logical channels are set, it is desired that packets between them be sent continuously without too much delay.

Therefore, it is necessary to control the amount of data flowing into the network to prevent large delays. Here, a method is used to limit the inflow when setting up a virtual call type packet transmission call. When restricting the inflow of calls, it is necessary to measure the amount of traffic on the network, but this requires mutual collection of statistics between mutual nodes, which is very difficult! c! I Requires complicated operations. The method used here is to control the inflow based on the response time of the call setup packet. Even if the call setup response time is a certain amount of traffic, it is distributed over a certain time range, so it cannot necessarily be said to be an accurate traffic estimation. In this case, if priority control is introduced and call setup packets are given a lower priority than normal packets, the response time distribution of call setup packets will be smaller, traffic setup will be more accurate, and congestion will be greater. In some cases, it is possible to reliably cause the PP setting to fail. As described above, the present invention is characterized in that inflow into the network is restricted by setting priorities separately for virtual call type call setup packets and other packets.

Next, the present invention will be explained in detail with reference to the drawings.

The third wi is the first embodiment of the present invention. In the figure, the determining means 21 determines whether the bucket F data that enters the degenerate receiving device 2 from the terminal device l is a call setup request packet or something else.
The timer No. 3 is started, and the packet and the judgment information are sent to the priority adding means 22, and the means 22 assigns a low priority to the packet and sends it to the data communication M3, and packets other than the call setup request packet are given priority. Degree adding means 22
It is given a high priority and sent to the network 3.

On the other hand, the packet type received from the network 3 is determined by the determining means 24, and if it is a call request packet, a response packet is created by the response packet creating means 25, and the priority adding means 22 creates a response packet with a lower priority. is attached and sent to the network 3. When the determination means 24 receives a response packet to the call setup, the timer of the call setup abandonment means 23 is reset and the packet is sent to the terminal 1. Further, if the packet determined by the determining means 24 is not related to call setup, the packet is immediately sent to the terminal l.

When the timer of the call setting abandonment means 23 times out, the terminal 1 is notified of call abandonment. Here, the response packet creation means 25 is not necessarily included in the vertical transmitting/receiving device, but may be included in the terminal device.

FIG. 4 shows a second embodiment of the invention. In the figure, the packet data input from the terminal device 101 to the vertical transmitting/receiving device 102 is judged by the determining means 121 as to whether it is a call setting request packet or something else, and if it is a call setting packet, a timer of the call setting abandonment means 123 is activated. The gosekatsu packet and the determination information are sent to the packet access means 122, and the means 1
22, access to the medium 103 (bucket) is attempted using an access means with a low priority, and packets other than those for requesting a call setup fee are accessed to the medium 103 by an access means with a high priority in the packet access means 122. An attempt is made to access the . On the other hand, among the packets sent to the medium 103, those addressed to the local station are received by the receiving means 126 and sent to the determining means 124. The determination means 124 determines the type of the packet, and if it is a call setup request packet, the response packet creation means 125 creates a response packet, and the packet access means 122 allows an access means with a low priority to access the medium 103. attempted. When the determining means 124 receives a response packet to the call setting, the timer of the call setting abandonment means 123 is reset;
The packet is sent to terminal 101. Also, the determination means 12
If the packet determined in step 4 is not related to call setup, the packet is sent to the terminal 101. In addition to the reception of the response packet described above, the means for controlling the reset of the timer can also be reset when the call setting packet is successfully accessed by the packet access means 122. In this case, the need for a response packet to the call setup request packet is not particularly necessary for inflow restriction.
Therefore, the determination means 124 and the response packet creation means 12
5 becomes unnecessary in the vertical transmitting/receiving device, and the receiving means 126
All packets received are sent directly to the terminal device 101. In either method, when the timer of the call setting means 123 times out, the terminal 101 is notified of call abandonment, and when the reset is performed by the packet access means, when the timeout occurs, the packet access means If the terminal is reset, the call setup is notified to the terminal, and the access to packets for call setup is temporarily abandoned. Here, response packet creation means 1
25, the means 125 is not necessarily included in the vertical transmitting/receiving device, but may be included in the terminal device. Next, a more detailed embodiment of the determining means 21 and the determining means 121 is shown in FIG.

In FIG. 5, terminal 211 has terminal 1 or terminal 101.
Packets from . An example of the format of a packet coming from terminal 1 or terminal 101 is shown in FIG. In the format, each item other than information consists of a bit string of several bits. Terminal 211 in FIG.
The extracting means 212 extracts the packet type part in the format shown in FIG. This extraction can be performed by counting the number of bits that have passed since the flag bit of the packet. The bit pattern extracted by extraction means 212 is decoded by decoder 213 and judgment information is output to terminal 214. Also, the packet output from the extraction means 212 is delayed by the register 215 and is received by the terminal 216.
is output to.

As explained above, the present invention has the effect that it is possible to restrict the inflow of packets into the network by configuring access with different priorities for virtual call type packet transmission. This is effective when data is sent continuously at a substantially constant speed, such as when data is sent in packets.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams explaining the configuration of a data communication network. J is a diagram showing a first practical example of the present invention, and FIG. 4 is a format of a packet of a second example of the present invention. In the figure, 1,101 is a terminal device %2, 102 is a vertical transmitting/receiving device, 3 is a data communication network, 103 is a medium, 21,
24, 121, 124 are determining means, 23, 123 are call setting abandonment means, 25, 125 are response packet creating means, 2
2 is a priority addition means; 122it is a packet access means; 126id packet reception means; 212 is an extraction means;
213 is Deco-f 1 Concave second gall O 3 Flash spear 4 Figure f May'1'6 Figure-35"

Claims (1)

[Claims] 1. In a data communication network capable of transmitting packetized data, 1.
a network, and a plurality of network transmitting/receiving devices capable of receiving virtual call type packet transmission from a terminal device; A means for assigning a high level of priority to packets other than those on the bucket, and a means for assigning a low priority to packets for call setup and sending them to the network, and when a call setup request packet arrives from the network. It is characterized by having means for responding to this, and means for abandoning the call setup and returning abandonment information to the terminal device if there is no response from the other station to the transmission of the call setup packet within a predetermined time. Data communication method. 2. In a data communication network in which packetized data is accessed by multiple network transmitting/receiving devices sharing a single medium, there is provided a means for accessing the network with at least two priority levels, and a means for accessing the network from a terminal device to a virtual call type. A means for accepting packet transmission, and a means for returning a call establishment abandonment to the terminal device when a call setup request packet is received from the terminal device in virtual fool type packet transmission. Among virtual call type packets, packets other than packets for call setup are accessed with a high priority level, and call setup packets are accessed with a low priority level. 1. A single data communication system characterized by comprising a plurality of network transmitting/receiving devices capable of performing call setup and abandoning call setup if access to the network cannot be established within a predetermined time. 3. In a data communication network in which packetized data is accessed by multiple vertical transmission/reception devices sharing one medium, there is a means for accessing the network with at least two priority levels and a virtual call from the terminal device. means for receiving a call setup request packet from the media in packet transmission of a virtual call; The terminal device is equipped with a means for sending an abandonment back to the terminal device, and accesses the network with a high priority level for packets other than call setup packets among virtual call type packets received from the terminal device. A plurality of degenerate systems that access the network with a low priority level for call setup packets and can abandon the call setup if a response packet to the call setup request is not received from the network within a predetermined time. A data communication method characterized by being equipped with a receiving device.