JP6258376B2 - Uninterruptible switching system, uninterruptible receiving device, uninterruptible switching method, and uninterruptible switching program - Google Patents

Description

  The present invention transmits the same frame copied from the uninterruptible transmission device to the long delay transmission line and the short delay transmission line, and the uninterruptible reception device preferentially outputs the frame that arrives first. The present invention relates to an instantaneous interruption switching system, an uninterruptible reception device, an uninterruptible switching method, and an uninterruptible switching program.

  In the 1 + 1 uninterruptible switching system, the same frame copied to the transmission lines of the 0-system and the 1-system is transmitted from the transmission side node, and one frame is selected at the reception side node and transmitted to the subsequent stage. Usually, in the TDM service, in order to avoid delay fluctuation at the time of uninterruptible switching, the signal of the short delay transmission line that arrives first at the receiving node among the transmission lines of the 0 system and the 1 system, and arrives later Since the signal of the long delay transmission line is waiting, the system delay is fixed to the long delay transmission line.

  On the other hand, in the case of uninterrupted switching of Ethernet (registered trademark), the condition for delay change due to switching of the frame selection path is relaxed rather than TDM, so that frame waiting becomes unnecessary. In other words, the receiving node performs first-come-first-served uninterruptible switching in which a frame having a normal sequence number that arrives early is selected and transmitted. Usually, since the frame of the short delay transmission line arrives first, as long as the sequence number of the frame of the short delay transmission line continues, the delay can be reduced by preferentially transmitting the first received frame.

FIG. 6 shows a configuration example of a waiting processing unit of a conventional uninterruptible switching system and an uninterruptible receiving device (Patent Document 1).
In FIG. 6 (a), the uninterruptible transmission device 10 transmits the same frame duplicated by assigning a sequence number to the input frame to the long delay transmission line and the short delay transmission line. The uninterruptible receiving device 20 detects the sequence number of the arriving frame in the selection unit 21 and the selection control unit 22 of the queuing processing unit shown in FIG. 6B, and selects and transmits the first arriving frame. . Normally, the first short delay transmission line frame is selected and transmitted. Note that the short delay type waiting buffer 23 and the long delay type waiting buffer 24 transfer without buffering when each transmission line is normal.

  Here, when a sequence number skip occurs at the time of a short path transmission line failure, the selection control unit 22 detects and notifies the read control unit 25, and under control of the read control unit 25, a short delay system queuing buffer. 23, the frame arriving from the short delay transmission line is waited until the frame of the corresponding sequence number arrives from the long delay transmission line. The read control unit 25 sequentially reads the frames in the waiting buffers 23 and 24 in accordance with the following waiting control.

FIG. 7 shows an example of waiting control described in Patent Document 1.
In Fig. 7 (a), when the second frame is lost on the short delay transmission line, the third and subsequent frames that have been normally transmitted on the short delay transmission line are to ensure the continuity of the sequence number. The system waits until the second frame arrives from the long delay transmission line. At this time, an upper limit of the waiting time (specified waiting time) is set. When the second frame arrives from the long delay transmission line within the specified waiting time, the frame is output as it is, and the third and subsequent frames of the short delay transmission line that have been waiting are sequentially read and output.

  Here, the specified waiting time is the upper limit of the waiting time from the start of waiting for the third frame arriving from the short delay transmission line until the arrival of the second frame from the long delay transmission line. As shown in FIG. 7 (b), if the second frame does not arrive from the long delay transmission line even after the specified waiting time has passed, it is determined that the frame has been lost, and the short delay system that has been waiting has been received. The third and subsequent frames on the transmission line are sequentially read and output.

  When the third frame arrives from the long delay transmission line, the loss of the second frame can be detected. For example, if the long delay transmission line breaks down, the third and subsequent frames are also detected. If it does not arrive, if the specified waiting time is not provided, the subsequent processing will be stopped.

JP 2012-178665 A

  The queuing control shown in FIGS. 6 and 7 enables uninterrupted switching even if there is a frame loss in the transmission path.

  By the way, in a network composed of a short delay transmission line and a long delay transmission line, when the traffic becomes large, the delay becomes large due to crossing traffic, waiting due to priority control, etc., and the delay fluctuation also becomes large. In Patent Document 1, a fixed prescribed waiting time is set in accordance with the worst value of the delay and the delay fluctuation.

  However, when the traffic is small, the delay and delay fluctuation are small, and the waiting time can be shortened, thereby enabling a low delay, but such a flexible response is not assumed.

  Also, when bursty traffic is input, depending on the buffer capacity of the device that becomes the bottleneck in the network, the shaping function in the network input side device (uninterruptible transmission unit 10 shown in FIG. 6), etc. In order to suppress burstiness and adjust (wait) the frame interval, the delay and delay fluctuation vary more than usual.

  Here, when the specified waiting time is set short as shown in FIG. 8 and the delay and delay fluctuation greatly fluctuate in the burst, it is impossible to wait for the second frame of the long delay transmission line. In this case, the frames after the third of the short delay transmission line that have been waiting are read out, and the order of the frames may be reversed.

  The present invention provides an uninterruptible switching system, an uninterruptible receiving device, an uninterruptible interrupt, which can flexibly set a waiting time corresponding to traffic fluctuations and bursts, can cope with frame loss, and can achieve low delay. An object is to provide a switching method and an uninterruptible switching program.

In the first invention, a sequence number is assigned to a frame to be input and duplicated, and an uninterruptible transmission device for transmitting each to two transmission paths and a frame arriving from the two transmission paths are input, and the sequence numbers are assigned in advance. When a frame loss is detected due to a missing sequence number on one transmission path, a predetermined waiting time elapses until a frame with that sequence number arrives from the other transmission path In the uninterruptible switching system including the uninterruptible receiving device including the queuing processing unit for queuing a frame arriving from one transmission path, the queuing processing unit is configured to determine a delay time difference between the two transmission paths in units of frames. Alternatively , a period T is defined as a period for detecting an average value of traffic fluctuations due to delay fluctuations, and traffic of two transmission lines in the period T is defined. A traffic fluctuation detection unit that detects a traffic fluctuation and variably sets the next period T according to a magnitude relationship between the traffic fluctuation and a predetermined value; and a frame according to a magnitude relation between the traffic fluctuation and the predetermined value in the period T. the average waiting time is variably set to perform waiting, and a mean waiting time setting unit for controlling the queuing of the frame.

  In the uninterruptible switching system of the first invention, the traffic fluctuation detecting unit sets the next period T longer than the previous period when the traffic fluctuation in the period T is smaller than a predetermined value, and the traffic fluctuation in the period T is a predetermined value. If it is larger, the next period T is set shorter than the previous period, and the average waiting time setting unit sets the next average waiting time shorter than the previous time when the traffic fluctuation in the period T is smaller than a predetermined value. When the traffic fluctuation in the period T is larger than a predetermined value, the next average waiting time is set longer than the previous time.

  In the uninterruptible switching system according to the first aspect of the present invention, the traffic fluctuation detecting unit resets the current period T when the traffic fluctuation indicates a burst based on the traffic fluctuation rate or the increase amount or the frame interval and The short period T is set, and the average waiting time setting unit is configured to reset the average waiting time and set a predetermined maximum allowable delay time.

  In the uninterruptible switching system according to the first aspect of the invention, the average waiting time setting unit is configured to set the average waiting time with a predetermined maximum allowable delay time as an upper limit.

In the second aspect of the invention, a sequence number is assigned to a frame to be input and duplicated, and an uninterruptible transmission device that transmits each of the two transmission paths and a frame that has arrived from the two transmission paths are input. When a frame loss is detected due to a missing sequence number on one transmission path, a predetermined waiting time elapses until a frame with that sequence number arrives from the other transmission path In the uninterruptible receiver of the uninterruptible switching system including the uninterruptible receiver including the queuing processor that waits for a frame arriving from one transmission path, the queuing processor includes two transmission paths A period T is defined as a period for detecting an average value of traffic fluctuation due to a delay time difference or a delay fluctuation of each frame, and two periods in the period T are defined. A traffic fluctuation detection unit that detects the traffic fluctuation of the transmission path of the transmission line and variably sets the next period T according to the magnitude relation between the traffic fluctuation and the predetermined value, and the magnitude relation between the traffic fluctuation in the period T and the predetermined value. Accordingly, an average waiting time for waiting for frames is variably set, and an average waiting time setting unit for controlling the waiting for frames is provided.

3rd invention assign | provides a sequence number to the frame input in an uninterruptible transmission part, duplicates it, transmits to each of two transmission paths, respectively. Input the arrived frame, output the first arrived frame in the order of the sequence number, and when a frame loss is detected due to a missing sequence number on one transmission line, the frame with the corresponding sequence number arrives from the other transmission line In the non-instantaneous switching method that waits for a frame arriving from one transmission path until a predetermined waiting time elapses, the waiting processing unit is configured to determine a delay time difference or delay fluctuation in units of frames of the two transmission paths. The period T is defined as a period for detecting the average value of the traffic fluctuations due to the traffic fluctuations, and the traffic fluctuation detection unit detects the traffic of the two transmission lines in the period T. Detecting a traffic fluctuation and performing a process of variably setting the next period T in accordance with the magnitude relationship between the traffic fluctuation and a predetermined value, and the average waiting time setting unit sets the magnitude relation between the traffic fluctuation and the predetermined value in the period T. In response to this, an average waiting time for frame waiting is variably set to control frame waiting.

  The non-instantaneous switching program of the fourth invention causes the computer to execute the processing of the traffic fluctuation detecting unit and the average waiting time setting unit of the waiting processing unit in the non-instantaneous switching system of the first invention, and according to the traffic fluctuation Control frame queuing.

  According to the present invention, the waiting time can be set flexibly in response to traffic fluctuations and bursts, so that it is possible to realize a low delay at the time of uninterruptible switching corresponding to frame loss.

It is a figure which shows the Example structure of the waiting process part of the uninterruptible switching system and uninterruptible receiver of this invention. It is a figure which shows the waiting control example 1 in this invention. It is a figure which shows the waiting control example 2 in this invention. It is a figure which shows the example of a setting of the period T and average waiting time in this invention. It is a figure which shows the example of a response | compatibility to the burst traffic in this invention. It is a figure which shows the structural example of the waiting process part of the conventional uninterruptible switching system and an uninterruptible receiver. It is a figure which shows the example of waiting control described in patent document 1. FIG. It is a figure explaining the subject with respect to burst traffic.

  FIG. 1 shows an embodiment configuration of a queuing processing unit of an uninterruptible switching system and an uninterruptible receiving apparatus according to the present invention.

  In FIG. 1, the basic processing functions of the selection unit 21, the selection control unit 22, the short delay type waiting buffer 23, the long delay type waiting buffer 24, and the read control unit 25 are the same as the conventional processing function shown in FIG. This is the same as the configuration of the waiting processing unit of the instantaneous interruption receiving device. The present invention is characterized in that it further includes a traffic fluctuation detection unit 26, an average waiting time setting unit 27, and a maximum allowable delay holding unit 28, and controls the operation of the read control unit 25.

  The traffic fluctuation detection unit 26 detects a traffic fluctuation such as a delay time difference or a delay fluctuation in a frame unit between the long delay transmission line and the short delay transmission line, and determines the next period T according to the average value of the traffic fluctuation in the period T. And a burst is detected based on the traffic fluctuation rate, the increase amount, the frame interval, and the like, and notified to the average waiting time setting unit 27. The average waiting time setting unit 27 calculates the average waiting time in the next period T according to the average value of the traffic fluctuations in the long delay transmission line and the short delay transmission line, and sets the average waiting time in the read control unit 25. The maximum allowable delay holding unit 28 holds the maximum allowable delay time defined by the network, and the average waiting time setting unit 27 reads and controls the average waiting time with the maximum allowable delay time held by the maximum allowable delay holding unit 28 as an upper limit. Part 25. For example, when the traffic fluctuation in the period T is smaller than a predetermined value, the next period T is lengthened and the next average waiting time is set short. When the traffic fluctuation in the period T is larger than a predetermined value, the next period T is shortened and the next average waiting time is set longer. When a burst is detected, the current period T and the average waiting time are reset, and the maximum allowable delay time is set as the shorter period T and the average waiting time.

  FIG. 2 shows a waiting control example 1 in the present invention. Here, an example of basic waiting control is shown regardless of the length of the average waiting time.

  FIG. 2A shows queuing control when the average queuing time is increased when the traffic fluctuation is large (average delay difference is large). When the second frame is lost on the short delay transmission line, the third and subsequent frames that have been normally transmitted on the short delay transmission line are transmitted from the long delay transmission line to ensure the continuity of the sequence number. Wait until the second frame arrives. At this time, when the second frame arrives from the long delay transmission line within a long average waiting time, the frame is output as it is, and the third and subsequent frames of the short delay transmission line that have been waiting are sequentially read. Output.

  FIG. 2B shows queuing control when the average queuing time is shortened when the traffic fluctuation is small (average delay difference is small). When the second frame is lost in the short delay transmission line, the system waits until the second frame arrives from the long delay transmission line. At this time, it is assumed that the second frame arrives from the long delay transmission line within a short average waiting time. When the frame arrives, the second frame is output as it is, and the short delay transmission line that has been waiting has been output. The third and subsequent frames are sequentially read and output.

  FIG. 3 shows a waiting control example 2 in the present invention. Here, an example of queuing control according to the length of the average queuing time when frame loss occurs in both the long delay transmission line and the short delay transmission line is shown.

  FIG. 3 (a) shows queuing control for determining frame loss within a long average queuing time. When the second frame is lost in the short delay transmission line, the third and subsequent frames that have been normally transmitted through the short delay transmission line wait until the second frame arrives from the long delay transmission line. . Here, if the third frame is confirmed without the second frame arriving from the long delay transmission line within the long average waiting time, the second frame loss is confirmed and the short delay transmission that has been waiting is performed. The third and subsequent frames on the road are sequentially read and output.

  FIG. 3B shows queuing control for estimating the frame loss within a short average queuing time. When the second frame is lost in the short delay transmission line, the third and subsequent frames that have been normally transmitted through the short delay transmission line wait until the second frame arrives from the long delay transmission line. . Here, since it is assumed that the second frame arrives from the long delay transmission line within the short average waiting time, the second frame arrives from the long delay transmission line within the short average waiting time. If not, the second frame loss is estimated, and the third and subsequent frames of the short delay transmission line that have been waiting are sequentially read and output. As a result, when the traffic waiting time is small and the short average waiting time is set, the frame loss is estimated by estimating the frame loss earlier than determining the frame loss after waiting for the arrival of the third frame from the long delay transmission line. Delay can be realized.

  FIG. 3 (c) shows queuing control for estimating frame loss within a long average queuing time. When the second frame is lost in the short delay transmission line, the third and subsequent frames that have been normally transmitted through the short delay transmission line wait until the second frame arrives from the long delay transmission line. . Here, when a long average waiting time is set, as shown in FIG. 3 (a), the third frame arrives from the long delay transmission line and the loss of the second frame is confirmed. If the third frame does not arrive as shown in (b), the second frame loss is estimated after the average waiting time has ended. However, if the average waiting time exceeds the maximum permissible delay time specified by the network, it will hinder uninterrupted switching. Therefore, the second frame loss is estimated with the maximum permissible delay time set separately, and the waiting time is met. The third and subsequent frames of the short delay transmission line are sequentially read and output. As a result, when the traffic fluctuation is very large such as in a burst, the frame loss can be estimated quickly by using the maximum allowable delay time as the upper limit of the average waiting time, thereby realizing a low delay.

FIG. 4 shows an example of setting the average waiting time in the present invention.
In FIG. 4, the traffic fluctuation detection unit (26 in FIG. 1) detects the average value of the traffic fluctuations in the long delay transmission line and the short delay transmission line in the period T, sets the next period T, and waits for the average. The time setting unit (27 in FIG. 1) is notified. When the traffic fluctuation in the period T is smaller than the predetermined value, the next period T is set to be longer, and when the traffic fluctuation in the period T is larger than the predetermined value, the next period T is set to be shorter. Further, the average waiting time setting unit (27 in FIG. 1) sets the average waiting time shorter than the previous time when the traffic fluctuation is smaller than the predetermined value, and sets the average waiting time as the previous time when the traffic fluctuation is larger than the predetermined value. Set longer.

  That is, since the traffic fluctuation is small in the section A, the period T of the section B is long and the average waiting time is set short. Next, when the traffic fluctuation increases in the section B, the period T of the section C is shortened and the average waiting time is set long. Next, if the state of large traffic fluctuation continues in the section C, the period T of the section D is shortened and the average waiting time is set long. Next, when the traffic fluctuation becomes small in the section D, the period T of the section E is set longer and the average waiting time is set shorter.

FIG. 5 shows an example of correspondence to burst traffic in the present invention.
In FIG. 5, when the traffic fluctuation detection unit (26 in FIG. 1) detects burst traffic with extremely large traffic fluctuation, it resets the period T and the average waiting time at that time, sets a period T shorter than the present time, Set the maximum allowable delay time as the waiting time.

  FIG. 5A shows a case where the duration of burst traffic is long. The period T and the average waiting time set in the section B are reset when a burst is detected, the period T of the section C newly set is shortened, and the maximum allowable delay time is set as the average waiting time. Next, in section C, although the traffic amount is large but the traffic fluctuation is small, the period T of section D is set long and the average waiting time is set short. Next, in section D, the traffic fluctuation increases due to the decrease in traffic volume, the period T of section E is shortened, and the average waiting time is set long with the maximum allowable delay time as the upper limit. Next, since the traffic fluctuation is small in the section E, the period T of the section F is set long and the average waiting time is set short. Next, since the traffic fluctuation is small in the section F, the period T of the section G is set long and the average waiting time is set short.

  FIG. 5B shows a case where the duration of burst traffic is short. The period T and the average waiting time set in the section B are reset when a burst is detected, the period T of the section C newly set is shortened, and the maximum allowable delay time is set as the average waiting time. Next, in section C, traffic fluctuations increase due to a sharp decrease in traffic volume, the period T of section D is shortened, and the maximum allowable delay time is maintained as the average waiting time. Next, since the traffic fluctuation is small in the section D, the period T of the section E is set long and the average waiting time is set short. Next, since the traffic fluctuation is small in the section E, the period T of the section F is set long and the average waiting time is set short.

  As described above, the operation after resetting the period T and the average waiting time differs depending on whether the duration of the burst traffic is long or short, but the average waiting time is immediately maximized by resetting the period T and the average waiting time. Since the allowable delay time can be set, as shown in FIG. 8, it is possible to avoid a situation in which the frame reversal occurs without waiting for the frame of the long delay transmission line while the specified waiting time remains short.

  The present invention can realize the processing of the traffic fluctuation detection unit 26 and the average waiting time setting unit 27 of the waiting processing unit in the uninterruptible switching system by a computer and a computer program that performs the above processing. This computer program can be stored in a computer-readable storage medium or provided via a network.

DESCRIPTION OF SYMBOLS 10 Uninterruptible transmission apparatus 20 Uninterruptible reception apparatus 21 Selection part 22 Selection control part 23 Short delay type waiting buffer 24 Long delay type waiting buffer 25 Read control part 26 Traffic fluctuation detection part 27 Average waiting time setting part 28 Maximum allowable delay holding section

Claims (7)

An uninterruptible transmission device that assigns a sequence number to an input frame, duplicates it, and transmits it to two transmission paths,
Frames arriving from the two transmission paths are input, and frames arriving first in the order of sequence numbers are output. When a frame loss is detected due to a missing sequence number in one transmission path, the corresponding transmission from the other transmission path An uninterruptible switching system including an uninterruptible receiving device including a queuing processing unit that waits for a frame arriving from one transmission path until a frame having a sequence number arrives or until a predetermined waiting time elapses. In
The queuing processing unit defines a period T as a period for detecting an average value of traffic fluctuation due to a delay time difference or delay fluctuation of each of the two transmission paths in a frame unit,
Detecting a traffic variation of the two transmission paths in the period T, a traffic variation detection unit for variably setting the next cycle T in accordance with the magnitude relationship between the traffic change with a predetermined value,
Wherein the average waiting time for waiting for the frame in accordance with the magnitude relationship between the traffic change with a predetermined value in the period T variably set, and a mean waiting time setting unit for controlling the queuing of the frame Non-instantaneous switching system. In the uninterruptible switching system according to claim 1,
The traffic fluctuation detection unit sets the next period T longer than the previous period when the traffic fluctuation in the period T is smaller than a predetermined value, and the next period when the traffic fluctuation in the period T is larger than a predetermined value. The period T is set shorter than the previous time,
The average waiting time setting unit sets the next average waiting time shorter than the previous time when the traffic fluctuation in the period T is smaller than a predetermined value, and when the traffic fluctuation in the period T is larger than the predetermined value. Non-instantaneous switching system characterized in that the next average waiting time is set longer than the previous time. In the uninterruptible switching system according to claim 1 or claim 2,
The traffic fluctuation detecting unit resets the current period T by resetting the current period T when the traffic fluctuation indicates a burst based on a traffic fluctuation rate or an increase amount or a frame interval, and the average waiting time setting unit. Is configured to reset the average waiting time and set a predetermined maximum allowable delay time. In the uninterruptible switching system according to claim 1 or claim 2,
The average waiting time setting unit is configured to set the average waiting time with a predetermined maximum allowable delay time as an upper limit. An uninterruptible transmission device that assigns a sequence number to an input frame, duplicates it, and transmits it to two transmission paths,
Frames arriving from the two transmission paths are input, and frames arriving first in the order of sequence numbers are output. When a frame loss is detected due to a missing sequence number in one transmission path, the corresponding transmission from the other transmission path An uninterruptible switching system including an uninterruptible receiving device including a queuing processing unit that waits for a frame arriving from one transmission path until a frame having a sequence number arrives or until a predetermined waiting time elapses. In the uninterruptible receiving device,
The queuing processing unit defines a period T as a period for detecting an average value of traffic fluctuation due to a delay time difference or delay fluctuation of each of the two transmission paths in a frame unit,
Detecting a traffic variation of the two transmission paths in the period T, a traffic variation detection unit for variably setting the next cycle T in accordance with the magnitude relationship between the traffic change with a predetermined value,
Wherein the average waiting time for waiting for the frame in accordance with the magnitude relationship between the traffic change with a predetermined value in the period T variably set, and a mean waiting time setting unit for controlling the queuing of the frame An uninterruptible receiving device. The frame input by the uninterruptible transmission unit is given a sequence number and duplicated, and transmitted to each of the two transmission paths.
In the queuing processing unit of the uninterruptible receiving unit, the frames arriving from the two transmission paths are input, the frames arriving first in the order of the sequence numbers are output, and the frame loss due to the lack of the sequence number in one transmission path In the non-interruptible switching method of waiting for a frame arriving from one transmission path until a frame having the sequence number arrives from the other transmission path or until a predetermined waiting time elapses,
The queuing processing unit defines a period T as a period for detecting an average value of traffic fluctuation due to a delay time difference or delay fluctuation of each of the two transmission paths in a frame unit,
Detecting a traffic variation of the two transmission paths in the period T in traffic change detection unit performs a process of variably setting the next cycle T in accordance with the magnitude relationship between the traffic change with a predetermined value,
An average waiting time setting unit variably sets an average waiting time for waiting for the frame in accordance with a magnitude relationship between the traffic fluctuation in the period T and a predetermined value, and controls the waiting of the frame. Instantaneous interruption switching method.   The computer performs the processing of the traffic fluctuation detecting unit and the average waiting time setting unit of the waiting processing unit in the uninterruptible switching system according to claim 1, and controls the waiting of the frame according to the traffic fluctuation. A non-instantaneous switching program.

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