JPH01120928A - Instantaneous packet transfer control system - Google Patents

Abstract

PURPOSE:To prevent an ineffective packet from being sent in a packet switching network by comparing the accumulation of delay times in a packet requiring instantaneous performance at every passing through a packet switching equipment with a limit and aborting the packet when the accumulation reaches the limit. CONSTITUTION:When a packet P reaches from an incoming relay line 5, an identification section 23 of a packet switching equipment 2 references a packet header part H of a received packet P and sends it to an instantaneous processing section 24 when identification information ID represents the instantaneousity. The instantaneous processing section 24 extracts a delay time DL included in a prescribed area and calculates a delay time D added in sending the packet P to an outgoing relay line 6 depending on the transmission speed C and the average packet length L of the outgoing relay line 6 and adds the delay time D to the delay time DL. The instantaneous processing section 24 compared the result of addition DL+D with a delay limit DM and discriminates the packet P to be an ineffective packet when the result exceeds the delay limit DM and abort the packet.

Description

[Detailed Description of the Invention] [Summary] This invention relates to an instant packet transfer control method in a packet switching network that transmits packets that require immediacy, especially when packets that require immediacy are transmitted through a packet switching network. The purpose of this is to prevent the transfer of invalid packets due to increased delay time as much as possible during transmission, and to reduce the invalid load on the packet switching network as much as possible. An area is provided in which delay information indicating the delay time incurred while the packet is transferred within the packet switching network is added to packets that require immediacy to be transmitted within the network, and in each packet switch,
The delay time indicated by the delay information included in the packet arriving from the incoming trunk line and the delay time added until the packet is sent to the Yamanaka'm line are added, and the addition result is calculated as a predetermined delay limit value. Compare and if the addition result is less than the delay limit value, update the delay information included in the packet to delay information indicating the addition result and send it to the outgoing trunk, and if the addition result is greater than or equal to the delay limit value. If so, the packet is configured to be discarded.

[Industrial application field]

The present invention relates to a packet switching network, and particularly to an instant packet transfer control system in a packet switching network that transmits packets that require instantaneous transmission.

In recent years, attempts have been made to packetize and transmit information that requires immediacy, such as voice, via a packet-switched network.

This type of packet may become invalid if the delay time that occurs while being transmitted within the packet-switched network reaches a predetermined limit.

[Conventional technology]

FIG. 5 is a diagram showing an example of a packet switching network to which the present invention is applied, and FIG. 6 is a diagram showing an example of a conventional packet switching device.

In FIG. 5, the packet switching network 1 is composed of a plurality of packet switches 1 (PS, >2), and a packet l-P is transmitted from a packet terminal 3 accommodated in the packet switching network 1 to another packet terminal 4 is transferred via a plurality of packet switches 2.

In FIG. 6, each packet switch 2 has a man line 5
When receiving a packet P arriving from a terminal, an outgoing trunk line 6 to which the packet P is to be transferred is selected, and the packet P is registered in a transmission queue 21 provided corresponding to the selected outgoing trunk line 6.

The packet P registered in the transmission queue 21 is sent to Yamanaka mvA.
Delay time D C = (i
+1)XL+C), it is transmitted to the outgoing trunk line 6.

Therefore, the packet P transmitted from the packet terminal 3 on the originating side (FIG. 5) takes the cumulative delay time of each packet switch 2 it passes through before reaching the packet terminal 4 on the destination side. will be subject to.

If a packet terminal (P) transmits information that requires immediacy such as voice, the destination packet terminal 4 monitors the delay time of each packet terminal (P) and determines the predetermined delay limit. A packet P that has suffered a delay time greater than or equal to the value of the packet P is discarded as an invalid packet.

[Problem that the invention seeks to solve]

As is clear from the above description, in a conventional packet switching network, each packet switch 2 transmits the packet I-P arriving from the incoming trunk line 5 to the outgoing trunk line 6 after a delay time has elapsed.

Therefore, the packet P, which requires immediacy, reaches the packet terminal 4 on the destination side and then reaches the packet switching network 1 when the cumulative delay time incurred while being transferred within the packet switching network 1 exceeds the delay limit value. The l-P is discarded as an invalid packet, and there is a problem in that the invalid packet is transferred within the packet switching network 1 and the invalid load increases.

An object of the present invention is to prevent as much as possible the transfer of invalid packets due to an increase in delay time when packets requiring immediacy are transmitted through a packet switching network, and to reduce the invalid load on the packet switching network as much as possible. do.

[Means for solving problems]

FIG. 1 is a diagram showing the principle of the present invention.

In Figure 1, ■ is the bucket intersection tA! ii, 2 is a plurality of packet switches constituting the packet switching network 1; 5 is the middle line of the packet switch 2; and 6 is the Yamanaka line of the packet switch 2.

P is a packet that is sent twice within the packet switching network 1 and requires immediacy.

DL is the delay time incurred until the packet P arrives at the packet switch 2.

D is a delay time added until the packet P is sent to the outgoing trunk line 6.

[Effect]

A packet P transmitted within the packet switching network 1 that requires immediacy is provided with delay information fla (DL) indicating the delay time DL.
) is provided.

Each packet switch 2 determines the delay time D indicated by the delay information 11 (DL) included in the bucket I-P arriving from the incoming trunk line 5.
L and the delay time added until the packet P is sent to the Yamanaka In line 6, and the addition result DL+D is compared with a predetermined delay limit value DH, and the addition result DL+D
is less than the delay limit value, the delay information (D+, ) included in bucket l-P is updated to delay information (DL + D) indicating the addition result DL + D, and transmitted to the output trunk line 6. .

Further, when the addition result DL+D reaches the delay limit value Di, the packet P is discarded.

Therefore, each time a packet that requires immediacy passes through a packet switch, the accumulated delay time is compared with a limit value, and when the limit value is reached, it is immediately discarded and transmitted within the packet switch network as an invalid packet. be prevented from being
The idle load on the packet-switched network is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a diagram showing a packet switch according to an embodiment of the present invention, FIG. 3 is a diagram showing a packet structure according to an embodiment of the present invention, and FIG. 4 is a diagram showing the instant processing process in FIG. It is a figure which illustrates. Note that the same reference numerals indicate the same objects throughout the figures. The target packet switching network is
As shown in Figure 5.

In FIG. 2, each packet switch 2 includes an identification unit 23 that identifies a packet P that requires immediacy, an immediate processing unit 24 that processes a packet P that requires immediacy, and an identification unit 24 that processes a packet P that requires immediacy. Waiting processing unit 25 that processes the packet P
is provided.

The register 22 also stores the number of packets registered in the transmission queue 21, that is, the transmission queue length i.

In FIG. 3, the packet header I (I) of a packet P transferred within the packet switching network 1 contains identification information ID indicating whether or not immediacy is required, and the packet header I-P that is transferred within the packet switching network 1. An area is provided to add delay information (DL) indicating the delay time DL incurred while being transferred.

In FIGS. 7 to 4, when a packet P arrives from the man line 5, the packet switch 2 selects an outgoing trunk line 6 to which the packet P should be transmitted using a known method, and The bucket I-P is transmitted to the identification unit 23 provided correspondingly.

The identification unit 23 refers to the packet header part H of the received packet P, analyzes whether or not the identification information ID indicates immediacy, and if it is found to indicate immediacy, transmits the information to the immediate processing unit 24. , and if it is determined that immediacy is not indicated, it is transmitted to the waiting processing unit 25.

The immediate processing unit 24 refers to the packet header section I of the received packet P, and extracts the delay information (DL
) to extract the delay time DL shown in Fig. 4, step S1.
), and the transmission queue length ゛i, accumulated in the register 22.
Based on the transmission speed C1 of the outgoing trunk line 6 and the average packet length, calculate the delay time D (=(H+1)xL+C) added when the packet P is sent to the outgoing trunk line 6.Step S2), delay time DL The delay time is added to the sum, and +D is obtained from the addition result (step 33).

The addition result DL+D indicates the cumulative amount of delay time that the packet P suffers in the packet switching network 1 when the packet switching device 2 transmits the packet to the outgoing trunk line 6.

Next, the immediate processing unit 24 processes the packet P for which immediacy is required.
A delay limit value D9 at which . It is compared with I (step S4).

As a result of the comparison, if the addition result DL+D is less than the delay limit value 08, it is determined that even if packet P is sent to Yamanaka W, line 6, it will not become an invalid packet, and the transmission accumulated in the register 22 Increase the queue length i by one step S5
), after updating the delay information (DL) included in a predetermined area of the packet header H of the packet P with the delay information (D, →-D) indicating the addition result DL +D (step S6).
, register the packet P in the transmission queue 21 (step S
7).

Note that as a result of the comparison in step S4, the addition result DL+
If D is equal to or greater than the delay limit value DH, it is determined that the packet P is an invalid packet, and is discarded without being registered in the transmission queue 21 (S ÷).

As is clear from the above description, according to the present embodiment, the packet switch 2 allows the packet P, which requires immediacy, to be transmitted to the outgoing trunk line 6 by the delay time (
If the addition result DL + D) is greater than or equal to the delay limit value DM, the Paqueso I-P considers it to be invalid packet 1 and discards it without transmitting it.
Transfer within A1 is prevented.

Note that FIGS. 2 to 5 are only one embodiment of the present invention, and for example, the delay information (DL) is not limited to indicating the delay time DL, and the transmission queue length may be used. Although many other modifications may be considered, the effects of the present invention remain the same in any case.

Further, the configurations of the packet switching network 1 and the packet switching equipment 2 are not limited to those shown in the drawings (although many other modifications may be considered, but the effects of the present invention will not change in any case.

〔Effect of the invention〕

As described above, according to the present invention, in the packet switching network,
Each time a packet that requires immediacy passes through a packet switch, the accumulated delay time is compared with a limit value, and when it is determined that the limit value has been reached, it is immediately discarded, and the packet remains in the packet switch network while remaining as an invalid packet. is prevented from being transmitted, reducing the idle load on the packet-switched network.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the invention, FIG. 2 is a diagram showing a packet switch according to an embodiment of the invention, FIG. 3 is a diagram showing a packet configuration according to an embodiment of the invention, and FIG. FIG. 2 is a diagram illustrating the instant processing process, FIG. 5 is a diagram illustrating an example of a packet switching network to which the present invention is applied, and FIG. 6 is a diagram illustrating an example of a conventional packet switching device. In the figure, 1 is a packet switching network, 2 is a packet switch (PS), 3 and 4 are packet terminals, 5 is an incoming trunk line, 6 is an outgoing trunk line, 21 is a transmission queue, 22 is a register, and 23 is an identification unit. , 24 is the immediate processing book in the month of the month, and the first one is the first one? 3b
5 Figure 1) 2 Cl2ji175 BpF'+* 1'1m'
FL% April

Claims (1)

[Claims] In a packet switching network (1) consisting of a plurality of packet switching devices (2), a packet (P) that requires immediacy and is transmitted within the packet switching network (1) is Delay time (D) incurred while the packet (P) is transferred within the packet switching network (1)
_L) is provided, and in each packet switch (2), the delay information ((D_L) included in the packet (P) arriving from the input trunk line (5) is added. )) is the delay time (D_
L) and the delay time (D) added until the packet (P) is sent to the outgoing trunk line (6), and the addition result (D_L+D) is set to a predetermined delay limit value (D_M ), and the addition result (D_L+D) is the delay limit value (D_M
), the delay information ((D_L)) included in the packet (P) is added to the addition result (D_L
+D) is updated to delay information ((D_L+D)) indicating the packet (P ) is an immediate packet transfer control method characterized by discarding packets.