JP2015099963A - Transmission device, transmission system and transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the buffer capacity for achieving the uninterrupted switching.SOLUTION: A packet transmission device having an uninterrupted switching function includes: a set band management table 205 having each flow and the set band information; a selective differential delay absorption packet buffer 211 and a nonselective differential delay absorption packet buffer 211; and a buffer control part 206 which refers to the set band management table 205 and allocates a buffer area of the differential delay absorption packet buffer 211 in accordance with the set band for each flow.

Description

  The present invention relates to a transmission apparatus, system, and method, and more particularly to a packet transmission apparatus, system, and method that have a non-instantaneous switching function and have a buffer area corresponding to a set bandwidth for each flow.

As background art of this technical field, “background art” described in Japanese Patent Application Laid-Open No. 2013-115584 (Patent Document 2) will be described.
In data communication in which data is transmitted / received continuously or intermittently between devices, even if a failure occurs in the communication line or node device, data communication can be continued through two different paths. There is a method for performing data communication between devices.

For example, in the 1: 1 switching (protection) method, the transmission-side apparatus normally transmits data only through the selected path, and when a failure occurs, the path for transmitting data is changed to a non-selected path. Switch. In this method, when a failure occurs in the selected path, the receiving device receives the data transmitted after the failure occurs until the transmitting device detects the failure and switches the path. I can't. As a result, the receiving device cannot receive a part of the data transmitted from the transmitting device (instant interruption).
On the other hand, in the 1 + 1 switching (protection) method, the transmission-side apparatus always transmits data including the same main body portion in the selected path and the non-selected path. Normally, the receiving side apparatus receives the same data in the main body transmitted via the selected path and the non-selected path. When the main unit receives the same data in a superimposed manner, the receiving-side apparatus selects the data received via the selected path and discards the data received via the non-selected path. When a failure occurs in the selected path, the receiving apparatus switches the path that has received the data to be selected from the selected path to the non-selected path. According to this method, even when a failure occurs in the selected path, the receiving apparatus receives the data transmitted from the transmitting apparatus via the non-selected path without loss. Can do.

  For example, Japanese Patent Laid-Open No. 2005-102157 (Patent Document 1) creates a copy of a packet on an apparatus on the transmission side, assigns a sequence number and an identifier for distinguishing the path to each frame, and uses a different path. At the same time, the receiving apparatus selects and transfers one of the two to realize the 1 + 1 switching method.

JP 2005-102157 A JP 2013-115584 A

In 1 + 1 uninterruptible switching that does not cause instantaneous interruption in data transmission, a buffer that absorbs a transmission delay difference due to a difference in transmission path is required in both the selection system and the non-selection system. In addition, when there are a plurality of nodes (packet transmission apparatuses) in the network, the receiving side apparatus needs to have a buffer capacity sufficient to realize uninterruptible switching for all transmission packets of each node. This buffer capacity increases according to the maximum transmission band, the allowable transmission delay difference, and the number of flows that can be accommodated in the node. A flow is, for example, a logical path (user line).
In recent years, with the increase in the number of users / transfer data amount, the number of accommodated paths and the transmission band (for example, from 40 Gbps to 100 Gbps) are steadily increasing. Therefore, an enormous buffer capacity is required to realize non-instantaneous switching that can cope with this situation.
However, in the publicly known technology (Patent Document 1), in order to realize non-instantaneous switching, it is only a buffer configuration that considers only whether the transmission / reception packet is a packet having the same information and the identification of its order, The required buffer capacity is not described, and the capacity is not conscious.

  In view of the above, an object of the present invention is to reduce the buffer capacity in a packet transmission device having a function of switching without interruption.

According to the first solution of the present invention,
A plurality of delay difference absorption packet buffers for absorbing the delay difference of the same data received from a plurality of paths;
A system selection unit for selecting one of the plurality of delay difference absorption packet buffers and outputting data;
A buffer control unit for controlling a plurality of delay difference absorbing packet buffers;
With
Each of the delay difference absorbing packet buffers includes a first buffer and a second buffer each having a buffer capacity of BWmax × P, where BWmax is a maximum transmission band and P is an allowable transmission delay difference, and the first or second buffer A selector for selecting a buffer of
The buffer control unit is provided with a transmission apparatus that allocates the first and second buffer areas of the delay difference absorbing packet buffer according to a bandwidth set for each flow.

According to the second solution of the present invention,
A transmission system,
Equipped with multiple transmission devices, the transmission device on the transmission side can send multiple identical data to two or more routes, and the transmission device on the reception side can select the data received from which route to the user or network And

The transmission device on the transmission side is:
A packet duplicator that duplicates the packet;
A bandwidth control unit that performs bandwidth control so that the total of the set bandwidths of all flows or a plurality of predetermined flows can be transmitted below the maximum transmission bandwidth BWmax when transmitting the packet replicated by the packet replication unit; With

The transmission device on the receiving side is
A plurality of delay difference absorption packet buffers for absorbing the delay difference of the same data received from a plurality of paths;
A system selection unit for selecting one of the plurality of delay difference absorption packet buffers and outputting data;
A buffer control unit for controlling a plurality of delay difference absorbing packet buffers;
With
Each of the delay difference absorbing packet buffers includes a first buffer and a second buffer each having a buffer capacity of BWmax × P, where BWmax is a maximum transmission band and P is an allowable transmission delay difference, and the first or second buffer A selector for selecting a buffer of
There is provided a transmission system in which the buffer control unit allocates the first and second buffer areas of the delay difference absorbing packet buffer according to a band set for each flow.

According to the third solution of the present invention,
A transmission method in a transmission system,
The transmission system is
Equipped with multiple transmission devices, the transmission device on the transmission side can send multiple identical data to two or more routes, and the transmission device on the reception side can select the data received from which route to the user or network And

In the transmission device on the transmission side,
Duplicate the packet,
When transmitting the duplicated packet, the bandwidth control is performed so that the total transmission bandwidth or the total of the set bandwidths of a plurality of predetermined flows is equal to or less than the maximum transmission bandwidth BWmax that can be transmitted,

In the transmission device on the receiving side,
With multiple delay difference absorption packet buffers, the delay difference of the same data received from multiple paths is absorbed,
When the maximum transmission bandwidth is BWmax and the allowable transmission delay difference is P, the buffer capacity of the first and second buffers included in each of the delay difference absorption packet buffers is BWmax × P, and the first or second buffer capacity is Select and output 2 buffers,
The areas of the first and second buffers of the delay difference absorbing packet buffer are allocated according to the bandwidth set for each flow,
Selecting one of the plurality of delay difference absorbing packet buffers and outputting data;
A transmission method is provided.

According to the present invention, it is possible to reduce the buffer capacity in a packet transmission device having an uninterruptible switching function.

Network configuration diagram. The block diagram of a transmission apparatus. Explanatory drawing about the management table holding the relationship of the setting zone | band of each flow set with the flow and the policer. Explanatory drawing about the delay difference absorption method for non-instantaneous switching function implementation | achievement. The non-instantaneous switching process flowchart in a transmission node. The non-instantaneous switching process flowchart in a receiving node. Explanatory drawing about the structure and required capacity | capacitance of a delay difference absorption packet buffer of related technology. Explanatory drawing about the structure and required capacity | capacitance of the delay difference absorption packet buffer of a present Example. Explanatory drawing about the comparison of the required capacity | capacitance of related technology and the delay difference absorption packet buffer of a present Example. FIG. 3 is a detailed block diagram of a buffer control unit and the like. The flowchart of the buffer process at the time of the setting change of a flow. Explanatory drawing about the process example (1/2) to the buffer at the time of a flow setting zone | band change. Explanatory drawing about a delay difference absorption packet buffer (initial state). Explanatory drawing about the processing example (2/2) to the buffer at the time of a flow setting zone | band change. Explanatory drawing about delay difference absorption packet buffer (it changes to flow 0 setting bandwidth 0). The detailed block diagram of the buffer control part etc. which have one packet buffer for temporary storage.

Hereinafter, examples will be described with reference to the drawings.

1. First embodiment

FIG. 1 is a network configuration diagram described in this embodiment. The packet transmission apparatuses 101 to 104 having a plurality of paths are provided, and in order to ensure reliability, the transmission apparatuses have a ring configuration having two paths that are redundant configurations. Data is transmitted / received between adjacent transmission apparatuses, and data is transmitted / received to the destination by relaying each transmission apparatus.

In this embodiment, the transmission apparatus A (101) is described as a transmission node, and the transmission apparatus B (102) is described as a reception node. A long physical path from the transmission node A (101) to the reception node B (102) through the transmission devices 104 and 103 is physically connected directly to the reception node B (102) from the transmission node A (101). A short route is called a short hand. A flow is, for example, a logical path (user line) from a transmission node to a reception node, and there are a plurality of flows between transmission apparatuses. In this embodiment, flow 0 will be described. Flow 0 passing through the long side is represented as flow 0L (105), and flow 0 passing through the short side is represented as flow 0S (106). The maximum accommodated flow number of the transmission apparatuses 101 to 104 is N.
Each of the transmission apparatuses 101 to 104 is connected to a user network and managed by the network management apparatus 107.

  FIG. 2 shows a block diagram for realizing the non-instantaneous switching function in the transmission apparatuses 101 to 104. The non-instantaneous switching function is a function that continues transmission without packet loss, packet increase, order reversal, etc. without causing an instantaneous interruption of data transmission / reception in the event of a failure. In order to realize such a function, it is necessary to wait for a packet from the long side after receiving a packet from the short side, and a buffer is necessary.

The transmission unit of the transmission node 101 has the following configuration.
Sequence number giving unit 203 that gives a sequence number to the transmission packet
A packet duplicating unit 201 for duplicating a packet assigned a sequence number by the sequence number assigning unit 203
A policer (bandwidth control unit) 202 that performs bandwidth control when a packet copied by the packet replication unit 201 is transmitted.

  The reason for performing the bandwidth control by the policer 202 may be, for example, preventing the delay difference absorbing packet buffer 211 in the receiving unit of the receiving node 102 from overflowing or allowing the user to observe the set bandwidth. For bandwidth control, an appropriate bandwidth control unit having functions such as a shaper, classification, admission control, and queuing used in QoS (Quality of Service) may be used instead of a policer.

The receiving unit of the receiving node 102 has the following configuration.
Overall control unit 204 that acquires bandwidth information from the network management device 107 that manages bandwidth information for each flow set by the policer of each node
A set bandwidth management table 205 that receives and manages bandwidth information for each flow from the overall control unit 204
Delay difference absorbing packet buffer 211 for absorbing a delay difference due to a difference in transmission distance
A buffer control unit 206 that refers to the set bandwidth management table 205 and allocates an area of the delay difference absorption packet buffer 211.
Sequence number management unit 207 that manages the arrival order of packets
Delay difference measurement unit 210 that measures the delay difference of packet arrival times
An output time generation unit 209 that determines an output time based on the sequence number of the sequence number management unit 207 and the delay difference information of the delay difference measurement unit 210
A time stamp assigning unit 208 that obtains a timing for reading a packet from the delay difference absorbing packet buffer 211 from the output time generating unit 209 and assigns a time stamp to the packet.
A system selection unit 212 that compares the sequence numbers given to the selected and non-selected packets and selects which of the selected and non-selected packets is to be transmitted.

  Here, the selection system represents a path that is used for data transmission / reception, and the non-selection system represents a path that is not used for data transmission / reception, and corresponds to either a short path or a long path.

  FIG. 3 shows an example of the contents of the set bandwidth management table 205 that holds the relationship between each flow and the set bandwidth of the policer. The set bandwidth for each flow can be set by a policer using the network management apparatus 107 by a system administrator, for example. When the setting band of flow 0 is BW0, the setting band of flow 1 is BW1, and the setting band of flow N-1 is BWN-1, the sum of the setting bands of all flows (BW0 + BW1 +... + BWN-1) is the maximum transmission band BWmax. Set to be: BWmax is, for example, the maximum value of the transmission band of the route from the transmission source to the transmission destination.

  FIG. 4 shows an example of a method for absorbing a delay difference due to a transmission distance difference for realizing the non-instantaneous switching function. The output end of the transmission node 101 is referred to as a transmission end, the input end of the reception node 102 is referred to as a reception end, and the input end of the system selection unit 212 of the reception node 102 is referred to as a termination end output.

  The sequence number assigning unit 203 assigns sequence numbers to the packets A (401), B (402), C (403), and D (404) transmitted from the transmission node 101. A packet 409 to which a sequence number is assigned has, for example, a header, a sequence number, a user packet, and a footer. However, this configuration is an example, and the sequence number only needs to be assigned to the user packet, and the position to be assigned is not limited to this. The packet duplication unit 201 duplicates the packet A (401), the packet B (402), the packet C (403), and the packet D (404) to which the sequence numbers are assigned. The transmission node 101 transmits a packet assigned with a sequence number through the policer 202 to two paths of a selection system and a non-selection system. In this case, a transmission distance difference occurs between the two routes of the selection system and the non-selection system, so that a transmission distance difference occurs, and a difference occurs in the packet arrival time at the receiving end. Therefore, the receiving node 102 receives the packet A (401), the packet B (402), the packet C (403), and the packet D (404) transmitted from the short direction of the transmitting node 101, and then is transmitted from the longitudinal direction. Until the packet packet A (405), packet B (406), packet C (407), and packet D (408) are received, the packet from the short direction is kept waiting for the delay time generated by the transmission distance difference.

  The delay difference absorbing packet buffer 211 requires a capacity corresponding to an allowable transmission distance difference in the system configuration, and the system administrator can determine the allowable transmission distance difference. The allowable transmission distance difference is, for example, a distance that can be switched without interruption requested by an administrator or the like for the system.

Next, the system selection unit 212 of the receiving node 102 compares the sequence numbers of the packet A (401) that arrives first and the packet A (405) that arrives later, and if the sequence numbers match, they are the same packet. Therefore, it is determined that no packet drop has occurred in the selection system, and packet A (401) from the short direction is transmitted to the user network ahead of the receiving node 102. Similar processing is performed on the packet B (402, 406), the packet C (403, 407), and the packet D (404, 408). When the packet transmission from the transmission node 101 to the reception node 102 is the first time, it is not determined which of the short and long paths is the selection system, so the path on which the packet arrives first can be the selection system.
When the system selection unit 212 detects a dropped packet in the selection system, the system selection unit 212 can continue transmission without causing an instantaneous interruption by switching from the selection system to the non-selection system.

FIG. 5 shows an example of a processing flowchart of the transmission node 101 that realizes switching without instantaneous interruption.
The transmission node 101 performs processing 501 for assigning a sequence number to the packet received from the user. Thereafter, the transmission node 101 performs a process 502 for duplicating the received packet assigned the sequence number, and performs a process 503 for transmitting the duplicated packet to the two paths in the short direction and the long direction (selected system and non-selected system). carry out.

FIG. 6 shows an example of a processing flowchart of the receiving node 102 that realizes uninterruptible switching.
The receiving node 102 manages the sequence number of the packet received from the selected system and the non-selected system by the sequence number management unit 207, and outputs the ideal output time from the delay difference measured by the delay difference measurement unit 210 by the output time generation unit 209. A determination process 601 is performed.
In the receiving node 102, the time stamp assigning unit 208 performs processing 602 that assigns a time stamp to the received packet and transfers it to the delay difference absorbing packet buffer 211 of each of the selected system and the non-selected system.
In the receiving node 102, the system selection unit 212 determines the time for reading the packet from the delay difference absorbing packet buffer 211 based on the time stamp, and performs processing 603 for reading the packet.

The receiving node 102 performs processing 604 for confirming whether or not a packet drop has occurred by comparing the sequence number assigned by the transmitting node 101 with the system selection unit 212 for the read packet. If no packet drop is detected, the receiving node 102 performs processing 606 for transmitting a packet without performing system switching by the system selection unit 212. If a packet drop is detected, the receiving node 102 performs a process 605 for switching to a non-selected system by the system selection unit 212 and performs a process 606 for transmitting a packet.
However, if the packet is dropped in both the selected system and the non-selected system in the process 604, the receiving node 102 proceeds to the process 606 so that the selected system maintains the previous value and does not need to perform system switching.

  FIG. 7 shows a configuration example of the delay difference absorbing packet buffer 211 of the related art. The maximum transmission band is BWmax, and the allowable transmission delay difference in which the allowable transmission distance difference is expressed in time is P. As the configuration of the delay difference absorbing packet buffer 211, a configuration 701 having a capacity corresponding to the number of accommodated flows and securing a buffer for each flow is one of the simplest configurations. When the buffer capacity for each flow is BWmax × P and the maximum number of accommodated flows is N, the required packet buffer capacity is BWmax × P × N. However, this requires a huge buffer capacity. For example, when BWmax = 100 [Gbps], P = 5 [ms] (transmission distance difference 1000 [km]), and N = 100 [lines], BWmax × P × N = 100 [Gbps] × 5 [ms] × A buffer capacity of 100 = 50 [Gbit] is required.

FIG. 8 shows a buffer configuration example of the present embodiment that solves the problem of increasing the buffer capacity. When the configuration 801 with buffer areas allocated according to the set bandwidth for each flow as shown in FIG. 3 is adopted, the buffer capacity of flow 0 is BW0 × P, the buffer capacity of flow 1 is BW1 × P, and the buffer capacity of flow 2 Is BW2 × P, the buffer capacity of the flow N-1 is BWN-1 × P, and the total necessary buffer capacity can be reduced to BWmax × P = 100 [Gbps] × 5 [ms] = 500 [Mbit]. . This is possible because the policer 202 adjusts the total set bandwidth of each flow to be within the maximum transmission bandwidth BWmax.
In addition, when the flow setting is changed (for example, when the flow setting band is changed), the data storage address of the delay difference absorption packet buffer 211 is vacant or overlapped, and fragmentation occurs or the data usage of the overlapped portion reduces the buffer usage efficiency. In order to prevent the decrease, the buffer 802 having the same capacity as the buffer 801 is prepared.

  FIG. 9 is a diagram comparing the buffer capacities of the configuration 701 that secures a buffer for each flow and the configuration 801 that allocates a buffer area according to a set bandwidth for each flow. As shown in the figure, it can be seen that the required buffer capacity can be reduced.

  FIG. 10 shows a detailed block diagram of the buffer control unit 206 that controls the delay difference absorbing packet buffer 211, the delay difference absorbing packet buffer 211, and the like. The buffer control unit 206 includes a set bandwidth management table access unit 1001 that performs access control of the set bandwidth management table 205, and a buffer access unit 1002 that performs access control of the packet buffer 1 (801) and the packet buffer 2 (802). . The selection-type and non-selection-type differential delay absorption packet buffers 211 are respectively configured to packet packet 1 (801) based on control signals from packet buffer 1 (801), packet buffer 2 (802), and overall control unit 204. ) Or packet buffer 2 (802), and a buffer selection unit (1003) for selecting whether to use.

FIG. 11 shows an example of a flowchart of buffer processing when the flow setting is changed.
The overall control unit 204 executes processing 1101 for waiting for a flow setting change notification from the network management apparatus 107. The setting change includes, for example, a setting change such as a bandwidth and / or a path.
When there is a notification of a change in the flow setting, the overall control unit 204 performs processing 1102 for determining whether or not the set bandwidth of each flow in the set bandwidth management table 205 has been set (for example, the presence or absence of data).
If it has not been set (No), the first packet buffer address allocation processing is performed.

  First, the overall control unit 204 performs processing 1103 for writing the set bandwidth information of the notified flow to the set bandwidth management table 205. Next, the overall control unit 204 performs processing 1104 that refers to the set bandwidth management table 205. Thereafter, the overall control unit 204 performs processing 1105 in which the buffer control unit 206 assigns a start address and an end address to the packet buffer 1 (801) according to the set bandwidth of each flow.

In the processing 1102, if the setting has already been made (Yes), either the packet buffer 1 (801) or the packet buffer 2 (802) is being used instead of the first address allocation processing.
Therefore, as a process, first, the overall control unit 204 executes a process 1106 for writing the notified set bandwidth information of the flow to the set bandwidth management table 205. Next, the overall control unit 204 performs processing 1107 that refers to the set bandwidth management table 205. Thereafter, the overall control unit 204 uses the buffer control unit 206 to reallocate the start address and the end address to the packet buffer 1 (801) or the packet buffer 2 (802) that are waiting according to the flow setting change. 1108 is performed.

  FIG. 12 and FIG. 13 show specific examples of processing when the bandwidth of flow 0 is changed to 0 in FIG.

  12A and 12B show a packet buffer 1 (801) and a packet buffer 2 (802), and an explanatory diagram and a table 1201 in which buffer capacity, start address, and end address for each flow are described. In the initial state where the flow is set, the buffer access unit 1002 of the buffer control unit 206 sets the start address of flow 0 to start_A0 and the end address of end_A0 (= start_A0 + BW0 × P) to the packet buffer 1 (801). Allocate buffer space. BW0 is a set bandwidth of flow 0, and P is an allowable transmission delay difference. The buffer access unit 1002 performs the same processing up to the flow N-1, determines a start address and an end address, and allocates a buffer area for each flow. In Table 1201, the start address and end address without initial values are addresses of the packet buffer 2 (802).

  13A and 13B are an explanatory diagram of buffer processing and a table 1201 when the set bandwidth of flow 0 is changed to 0. FIG. When the set bandwidth of the flow 0 becomes 0, a space is generated in the area from the address start_A0 to the end_A0 of the packet buffer 1 (801). Therefore, the buffer access unit 1002 fills the packet buffer 2 (802) with the area of the flow 0 and reallocates the areas from the flow 1 to the flow N-1. The buffer access unit 1002 assigns the start address start_B1 of flow 1 to address 0 of the packet buffer 2 (802) and the end address of flow 1 as end_B1 (= start_B1 + BW1 × P). Further, the buffer access unit 1002 allocates areas from flow 2 to flow N−1 following the flow 1 area. By doing so, a configuration in which fragmentation does not occur in the buffer area becomes possible.

  12 and 13 show examples in which the flow setting band is set to 0. However, when the setting band is increased or decreased, the packet buffer 2 (802) can be reassigned in the same manner.

As described above, according to the embodiment, in order to prevent a packet buffer area from being vacated when a flow setting is changed with respect to the packet buffer and fragmenting to occur, the packet buffer usage efficiency is reduced. Can be re-stored so that fragmentation does not occur in another buffer area.
Therefore, in this embodiment, the buffer capacity can be optimized by allocating the buffer area according to the set bandwidth for each flow.

2. Second embodiment

In the first embodiment, two packet buffers are provided for each of the selection system and the non-selection system. However, in order to manage data with one packet buffer, another packet buffer is provided. One buffer temporary storage packet buffer 1401 may be provided. FIG. 14 shows a configuration diagram of the buffer control unit 206 and the delay difference absorbing packet buffer 211 in this case.
When the flow setting is changed, the buffer access unit 1002 uses the temporary storage buffer 1401 (packet buffer 2 (802)) to reallocate the data in the delay difference absorbing packet buffer 211 (packet buffer 1 (801)). Then, the process of returning the data in the temporary storage buffer 1401 to the delay difference absorption packet buffer 211 is performed.

  The specific processing is similar, for example, by associating the packet buffer 1 (801) and the packet buffer 2 (802) of the first embodiment with the delay difference absorbing packet buffer 211 and the temporary storage buffer 1401, respectively. It is sufficient to execute the process. As a result, address reassignment is performed, and then the contents of the temporary storage buffer 1401 may be copied to the delay difference absorbing packet buffer 211.

As described above, according to the present embodiment, the buffer used for preventing fragmentation when the flow setting is changed is not provided in both the selection system and the non-selection system, but is temporarily used for data organization when the flow setting is changed. Need only have one buffer to store data.
Therefore, in this embodiment, the buffer capacity can be further reduced.

3. Appendix

In addition, this invention is not limited to said Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files for realizing each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

101 transmitting node (transmission apparatus A)
102 Receiving node (Transmission device B)
103 Transmission Device 104 Transmission Device 105 Flow 0L
106 Flow 0S
107 Network management device 201 Packet duplication unit 202 Policer 203 Sequence number assigning unit 204 Overall control unit 205 Setting bandwidth management table 206 Buffer control unit 207 Sequence number management unit 208 Time stamp assigning unit 209 Output time generation unit 210 Delay difference measurement unit 211 Delay Differential absorption packet buffer 212 system selection unit

301 Content example of set bandwidth management table 401 Packet A (selection type)
402 Packet B (selection type)
403 packet C (selection type)
404 packet D (selection type)
405 Packet A (non-selection type)
406 Packet B (non-selection type)
407 Packet C (non-selection type)
408 packet D (non-selection type)
409 Packet configuration 701 with sequence number added Delay difference absorbing packet buffer 801 of simple example Packet buffer 1
802 Packet buffer 2
1001 Setting bandwidth management table access unit 1002 Buffer access unit 1003 Buffer selection unit 1201 Delay difference absorption packet buffer configuration table 1401 Temporary storage packet buffer

Claims (15)

A plurality of delay difference absorption packet buffers for absorbing the delay difference of the same data received from a plurality of paths;
A system selection unit for selecting one of the plurality of delay difference absorption packet buffers and outputting data;
A buffer control unit for controlling a plurality of delay difference absorbing packet buffers;
With
Each of the delay difference absorbing packet buffers includes a first buffer and a second buffer each having a buffer capacity of BWmax × P, where BWmax is a maximum transmission band and P is an allowable transmission delay difference, and the first or second buffer A selector for selecting a buffer of
The buffer control unit is a transmission apparatus that allocates the first and second buffer areas of the delay difference absorbing packet buffer according to a bandwidth set for each flow.
The transmission device according to claim 1,
When the maximum accommodated flow number of the transmission apparatus is N, the buffer capacity of the flow n (n = 0 to N−1) is set to BWn × P according to the set bandwidth for each flow,
The maximum transmission band BWmax is
{BW0 × P + BW1 × P +... + BW (N−1)} × P
A transmission apparatus characterized by the above.
The transmission device according to claim 1,
On the sending side,
A packet duplicator that duplicates the packet;
A transmission apparatus comprising: a bandwidth control unit that performs bandwidth control when transmitting the packet replicated by the packet replication unit.
The transmission device according to claim 3,
The transmission apparatus according to claim 1, wherein the bandwidth control unit is configured to set a total transmission bandwidth or a total of predetermined bandwidths of a plurality of predetermined flows to be equal to or less than a maximum transmission bandwidth BWmax that can be transmitted.
The transmission device according to claim 1,
A setting bandwidth management table for managing bandwidth information for each flow;
An overall controller that refers to the set bandwidth management table, assigns bandwidths of the first and second buffers according to the bandwidth set for each flow by the buffer controller, and controls the selector; A transmission apparatus comprising:
The transmission device according to claim 5,
The overall controller is
When there is a notification of a flow setting change, a process of determining whether the set bandwidth of each flow in the set bandwidth management table has been set,
If set, the set bandwidth information of the notified flow is written in the set bandwidth management table, and the flow control unit changes the setting of the flow to a non-selected buffer according to the flow setting change. Processing to reallocate storage space;
A process of selecting an output of the first or second buffer that is not selected and that has been subjected to the process of reallocation by the selector;
The transmission apparatus characterized by performing.
The transmission device according to claim 6,
The overall control unit
If not set, processing for writing the set bandwidth information of the notified flow to the set bandwidth management table and allocating a storage area to the first buffer according to the change of the set bandwidth of the flow by the flow control unit When,
A process of selecting an output of the first buffer by the selector;
The transmission apparatus characterized by performing.
The transmission device according to claim 6,
The transmission apparatus according to claim 1, wherein the setting change is a band setting change or a path setting change.
The transmission device according to claim 1,
In the initial state in which the flow is set, the buffer control unit stores the start address of the flow n (n = 0 to N−1) in the first buffer and BWn × P (BWn is the flow n of the flow n). A transmission apparatus characterized in that a buffer area is allocated by setting an end address to which a set bandwidth, P is an allowable transmission delay difference).
The transmission device according to claim 9,
When the set bandwidth of a certain flow x becomes 0, increases, or decreases, the buffer control unit packs, increases, or decreases the area of the flow x of the selected buffer among the first or second buffers. And reallocating the remaining plurality of flow regions so that fragmentation does not occur.
The transmission device according to claim 1,
On the receiving side, the system selection unit
A process for confirming whether a packet drop has occurred by comparing the sequence numbers assigned by the transmission device on the transmission side;
When packet loss is not detected or when packet loss occurs in both the selected system and the non-selected system, a process of transmitting the packet without performing system switching;
A transmission apparatus, wherein when packet drop is detected, switching to a non-selection system and processing for transmitting a packet are executed.
The transmission device according to claim 1,
The delay difference absorbing packet buffer includes:
Sharing the second buffer with a plurality of delay difference absorbing packet buffers, omitting the selector;
The transmission apparatus according to claim 1, wherein the system selection unit selects one of the plurality of delay difference absorption packet buffers and outputs data.
The transmission device according to claim 12, wherein
The buffer control unit performs address reassignment on the data in the first buffer using the second buffer when the flow setting is changed, and then transfers the data in the second buffer to the first buffer. A transmission apparatus for copying to a buffer.
A transmission system,
Equipped with multiple transmission devices, the transmission device on the transmission side can send multiple identical data to two or more routes, and the transmission device on the reception side can select the data received from which route to the user or network And

The transmission device on the transmission side is:
A packet duplicator that duplicates the packet;
A bandwidth control unit that performs bandwidth control so that the total of the set bandwidths of all flows or a plurality of predetermined flows can be transmitted below the maximum transmission bandwidth BWmax when transmitting the packet replicated by the packet replication unit; With

The transmission device on the receiving side is
A plurality of delay difference absorption packet buffers for absorbing the delay difference of the same data received from a plurality of paths;
A system selection unit for selecting one of the plurality of delay difference absorption packet buffers and outputting data;
A buffer control unit for controlling a plurality of delay difference absorbing packet buffers;
With
Each of the delay difference absorbing packet buffers includes a first buffer and a second buffer each having a buffer capacity of BWmax × P, where BWmax is a maximum transmission band and P is an allowable transmission delay difference, and the first or second buffer A selector for selecting a buffer of
The transmission system according to claim 1, wherein the buffer control unit allocates the first and second buffer areas of the delay difference absorbing packet buffer according to a bandwidth set for each flow.
A transmission method in a transmission system,
The transmission system is
Equipped with multiple transmission devices, the transmission device on the transmission side can send multiple identical data to two or more routes, and the transmission device on the reception side can select the data received from which route to the user or network And

In the transmission device on the transmission side,
Duplicate the packet,
When transmitting the duplicated packet, the bandwidth control is performed so that the total transmission bandwidth or the total of the set bandwidths of a plurality of predetermined flows is equal to or less than the maximum transmission bandwidth BWmax that can be transmitted,

In the transmission device on the receiving side,
With multiple delay difference absorption packet buffers, the delay difference of the same data received from multiple paths is absorbed,
When the maximum transmission bandwidth is BWmax and the allowable transmission delay difference is P, the buffer capacity of the first and second buffers included in each of the delay difference absorption packet buffers is BWmax × P, and the first or second buffer capacity is Select and output 2 buffers,
The areas of the first and second buffers of the delay difference absorbing packet buffer are allocated according to the bandwidth set for each flow,
Selecting one of the plurality of delay difference absorbing packet buffers and outputting data;
Transmission method.

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