JPS61177049A - Inter-network connecting device - Google Patents

Abstract

PURPOSE:To process a packet having high real time property in priority by comparing the length of respective packets, processing the packets successively in the ascending order of length and sending the processed packets to a network when the number of packets stored in an inter-network connecting device exceeds a prescribed number. CONSTITUTION:Packet number deciding parts 107, 114 and packet length comparison processing parts 108, 114 are connected. The deciding part 107 decides whether the number of packets in a receiving buffer 103 exceeds the prescribed number or not, and if the number exceeds the prescribed number, informs the status to the processing part 108. The processing part 108 executes the comparing processing of sent packets, selects the packets in the descending order of the packet length and informs the selected result to a control part 109. Consequently, the control part 109 extracts the selected packet from a receiving buffer 103 and sends the extracted packet to a transmission line.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an inter-network connection device that interconnects networks, and more particularly to packet processing in the inter-network connection device.

(Prior art) Figure 2 shows a network 201 and a network 202.
A terminal (not shown) accommodated in a network 201 and a network 202 are connected via an inter-network connection device 203 to form a communication system.
In order to communicate between terminals (not shown) housed in the network, an inter-network connection device 203 that interconnects the networks 201 and 202 is required. An inter-network connection device is a device that performs the function of interconnecting networks. Therefore, assuming a wider communication network, a plurality of network connection devices (not shown) are connected to the network 201, and a plurality of network connection devices (not shown) are connected to the network 202. Other networks (not shown) are successively connected in such a manner that a comprehensive communication network is constructed.

In such a configuration, when a packet is sent from a source terminal accommodated in one network to a destination terminal accommodated in another network, the destination terminal is generally accommodated via several stages of network connection devices. reach the network you are using. Considering that packets pass through network interconnection equipment in multiple stages, in order to shorten the time required for the packet to travel from the originating terminal to the destination terminal, the packet is transferred to the network when passing through the network interconnection equipment. It is important to minimize the time spent in the interconnection device.

In particular, for voice packets that require real-time performance, these conditions must be strictly met. In conventional network connection devices, packets attempting to pass through the network connection device are processed in the order in which they arrive from the network, and sent to the next network without changing the order.

(Problem to be Solved by the Invention) However, in packet processing in such conventional network connection devices, packets are only processed in the order of arrival at each network connection device, and packets with high urgency are There was no consideration given to preferential processing and passage of the materials. For this reason, for example, the processing of data packets that can tolerate some delay and the processing of voice packets that can tolerate almost no delay are executed in the same dimension, so the delay time of voice packets is The problem is that the size increases as the number of stages increases, making natural voice communication impossible.

One way to solve this problem is to use the network connection equipment to determine whether packets passing through the network connection equipment are data packets or voice packets based on the packet identification code added to these packets. It is conceivable to make the determination within the interconnection device and process the audio packets with priority.

However, this method requires that the packet itself that passes through the network connection device is equipped with a packet identification code to determine whether the packet is for data or voice. If the inter-network connection device does not always know about the 4UiE of frames of various packets, the packet identification code cannot be recognized and the configuration becomes complicated.

Therefore, it is an object of the present invention to solve these problems and provide an inter-network connection device that has a simple configuration and processes highly real-time packets with priority.

(Means for Solving the Problems) The present invention is directed to an inter-network connection device that is provided between networks and temporarily stores packets received from the network and then sends them to the network. The present invention provides such an inter-network connection device with a first means for determining whether the number of stored packets is greater than or equal to a specified number, and a first means for determining whether the number of accumulated packets is greater than or equal to a specified number. The second step compares the length of each packet and processes the packets in descending order of packet length and sends them to the network.
This is because we have provided means for this.

(Operation) Packets received from the network are stored in the network connection device. The first means compares the number of stored packets with a predetermined number. If the number of stored packets is less than the specified number, the packets are processed in the order of arrival and sent to the network in the order of arrival, according to the normal operation of the network connection device. on the other hand,
When the number of accumulated packets is equal to or greater than the predetermined number, this fact is notified to the second means. The second means receives this notification, compares the lengths of each of the stored packets, processes the packets in descending order of packet length, and sends the packets to the network. As a result,
Packets with short packet length and high real-time characteristics are processed with priority and sent to the network.

(Example) The present invention will be described below based on an example with reference to the drawings.

First, the principle of this invention will be explained. This invention is
By utilizing the difference in packet length between packets with high real-time characteristics, such as voice packets, and packets with relatively low real-time characteristics, such as data packets,
Distinguish between voice packets and data packets. This utilizes the characteristic that voice packets have, as described below. That is, in order to ensure real-time performance, voice packets are packetized to reduce packet delay on the transmitting side. Therefore, the timing for generating voice packets is generally approximately every 8 seconds. In addition, in audio encoding using the PCM method, the audio code portion of an audio packet is at most 64
The packet length including the packet header is approximately 100 bytes. Therefore, the packet length of voice packets is generally shorter than the length of data packets (usually several kilobytes).Therefore, by utilizing the difference in the packet lengths of voice packets and data packets, network connection equipment can Voice packets can be selected from among the arriving packets. Therefore, it is possible to give priority to the processing of voice packets with high real-time performance.

Next, one embodiment of the present invention will be described. FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, transmission lines 101 and 106 are packet receiving units, 103 and 111 are packet receiving buffers,
104 and 112 are packet transmission buffers, 105 and 113 are packet transmission units, and 109 is a control unit. This is basically included in an inter-network connection device that temporarily stores packets and then sends the packets to the network via a transmission path. According to this embodiment, packet number determination sections 107 and 114 and packet length comparison processing sections 108 and 114 are newly provided. The packet number determination unit 107 determines whether the number of packets stored in the packet reception buffer 103 is greater than or equal to a predetermined number (specified number), and if the number is greater than or equal to the prescribed number, the packet count determination unit 107 determines whether the number of packets stored in the packet reception buffer 103 is greater than or equal to a predetermined number. The packet length comparison processing unit 108 via a
When the packet length comparison processing unit 108 receives the notification from the packet number determination unit 107, the packet length comparison processing unit 108 notifies the packet length information sent via the line 103b. The comparison process is executed, packets are selected in descending order of packet length, and the selection results are notified to the control unit 109 via the line 108a. At the time of selection, if there are a plurality of packets with the same packet length, the packet stored in the packet reception buffer 103 earlier in time is selected in order. The packet number determination unit 114 and the packet length comparison processing unit 115 also include
Packet number determination unit 107 and packet length comparison processing unit 10
It is configured similarly to 8.

Next, the operation will be explained. Note that since the configuration and operation of the components above the dashed-dotted line in the figure and the configuration and operation of the components below the dashed-dotted line are the same, only the portion above the dashed-dotted line will be described below.

Packets from transmission path 101 are taken into packet receiving section 102 . The packet receiving unit 102 determines whether this packet is valid or invalid, and if it is a valid packet, transfers this packet to the packet receiving buffer. When the packet is invalid, the packet is sent to the packet receiving unit 1.
It is discarded by extinguishing it within 02. The packet reception buffer 103 has an area for storing a plurality of packets. The packet reception buffer 103 sends packet storage number information indicating the number of packets stored therein to the packet number determination unit 107 via a line 103a.
to notify. The packet number determining unit 107 determines whether or not the notified packet number information is equal to or greater than the specified number.As a result of the 0 determination, when the packet number information is equal to or greater than the specified number, the packet number determining unit 107 determines whether or not the notified packet number information is equal to or greater than the specified number. The packet length comparison processing unit 108 is notified. On the other hand, as a result of the determination, if the packet number information is less than the specified number, the packet number determining section 107 does not notify the packet length comparison processing section 108 of anything.

When the packet length comparison processing unit 108 receives the notification,
The packet length comparison processing unit 10g executes a comparison process on the packet length information sent from the packet reception buffer 103 via the line 103b, selects packets in descending order of packet length, and sends the selection results via the line 108a. The determination unit 109 is notified. When there are multiple packets with the same packet length, the packets are selected in the order of the earliest received packet, and the control unit 109 receives the 0 notification sent to the control unit 109 via the line 108a.
The selected packet is taken out from the packet reception buffer 103 and instructed to be transferred to the packet transmission buffer 104. At this time, if it is necessary to add processing such as protocol conversion to the packet itself, the processing is performed according to instructions from the control unit 109. The packets stored in the packet transmission buffer 104 are taken out in the order in which they were stored in accordance with instructions from the control section 109 and transferred to the packet transmission section 105. Packet transmitter 105 sends the transferred packet to transmission path 10B.

On the other hand, the packet length comparison processing unit 108 determines whether line 10? If no notification is received from the packet number determination unit 107 via line 103a, the packet length comparison processing unit 108 ignores the information sent from the packet reception buffer 103 via line 103b, and sends the information to the control unit 109. Since there is no notification from the line 108a, the control unit 109 checks whether there is a packet in the packet reception buffer 103.

If the packet exists in the packet reception buffer 103, the control unit 108 instructs to take out the packet from the packet reception buffer 103 and transfer it to the packet transmission buffer 104. At this time, if there are a plurality of packets in the packet reception buffer 103, an instruction is given to take out the packets stored in the packet reception buffer 103 in the order of the earliest time and transfer them to the packet transmission buffer 104. When transferring a packet to the packet transmission buffer 104, if it is necessary to add processing such as protocol conversion to the packet itself, the processing is performed according to instructions from the control unit 108. The packets stored in the packet transmitter 104 are transferred to the packet transmitter buffer 104 according to instructions from the controller 109.
The packets are retrieved in the order in which they are stored, and transferred to the packet transmitter 105, and then transferred from the packet transmitter 105 to the transmission path 10B.
sent to.

As explained above, in the above embodiment, when the number of packets in the packet reception buffer waiting to be processed exceeds the specified number of packets passing through the network connection device, the length of the packets waiting to be processed is compared. By making a determination of 1, it is possible to give priority to packets with shorter packet lengths and allow them to pass through the network connection device. In addition, as another embodiment, the packet number determination section and the packet length comparison processing section may be provided in the packet transmission buffer.

(Effects of the Invention) As explained above, according to the present invention, when the number of accumulated packets exceeds a predetermined number of packets passing through an inter-network connection device, the packet Since the processing is given priority to those with shorter lengths, it is possible to provide an inter-network connection device with a simple configuration and high real-time performance. In general, packets for which real-time performance is important are generated with a short packet length on the packet sending side to reduce the packetization delay, so the present invention is extremely advantageous in maintaining real-time performance. Therefore, the present invention is suitable for application to a composite communication system that handles a combination of voice packets where real-time performance is important and data packets where real-time performance is not as important as voice packets. Furthermore, according to the present invention, when one sending side consciously communicates urgent information, the sending side processes the packet with priority within the network connection device by making the packet length as short as possible. This also has the effect of making it possible to transmit information to the other party extremely quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an inter-network connection device according to the present invention, and FIG. 2 is a diagram showing the configuration of a communication system having the inter-network connection device. 101.108-m-transmission line, 102.110-m-packet receiving unit. 103.111-m-packet receive buffer, 104.
112---Packet transmission buffer, 105.113-
m-packet transmitter, 10? , 114-m-packet number determination unit, 108.115-m-packet length comparison processing unit, 109-m-enactment unit. 103a, 103b, 107a, 108b --- line.

Claims (1)

[Claims] In an inter-network connection device provided between networks, which temporarily stores packets received from the network and then sends them to the network, there is a means for determining whether the number of stored packets is greater than or equal to a specified number; an inter-network connection characterized by comprising means for comparing the lengths of each packet when the number of packets being transmitted is equal to or greater than a predetermined number, and processing the packets in descending order of packet length and transmitting the packets to the network. Device.