WO2024017325A1

WO2024017325A1 - Optical switch and data communication system

Info

Publication number: WO2024017325A1
Application number: PCT/CN2023/108358
Authority: WO
Inventors: 闫付龙; 谢崇进
Original assignee: 杭州阿里巴巴飞天信息技术有限公司
Priority date: 2022-07-21
Filing date: 2023-07-20
Publication date: 2024-01-25
Also published as: CN114979844A; CN114979844B

Abstract

Provided in the present application are an optical switch and a data communication system. Each switching link in the optical switch in the present application is provided with a cache group. For any switching link, if the wavelengths of at least two optical packets that need to be output via the switching link in one slot are the same, optical packets, other than one of the optical packets, can be cached in the cache group in the switching link, and the one of the optical packets is output in the slot; and in a subsequent slot, the other optical packets cached in the cache group are scheduled and then output, such that a conflict can be prevented. In addition, the structure of the optical switch in the present application can support FFQ scheduling on optical packets, and FFQ retrieval can be ideal scheduling based on a GPS, such that a broadband guarantee can be achieved, for example, the throughput of the optical switch for the switching of the optical packets can be improved, thereby improving the quality of the optical switch for the switching of the optical packets, and obtaining a quality-of-service guarantee.

Description

An optical switch and data communication system

This application claims priority to the Chinese patent application filed with the China Patent Office on July 21, 2022, with the application number 202210855906.6 and the application title "An optical switch and data communication system", the entire content of which is incorporated into this application by reference. middle.

Technical field

This application relates to the field of new generation information technology, and in particular to an optical switch and a data communication system.

Background technique

Optical Packet Switching (OPS, Optical Packet Switching) is a packet switching method often used in optical communication scenarios. Data in optical communication scenarios is often reflected in optical packets. Optical packets can also be called optical packets. Optical packets include optical packet headers and optical packet loads. Optical switches can be used for optical packet switching. .

For example, optical switches can switch optical packets between two data centers.

However, with the prosperity and development of various applications in data centers, various applications in data centers have increasing demands for broadband quality. Current optical switches can provide sufficient bandwidth, but the quality of the bandwidth they can provide is low, which affects the quality of optical packet switching and lacks assurance of service quality.

For example, in one method, during the process of switching optical packets by an optical switch, sometimes some optical packets may have switching conflicts. When some optical packets have switching conflicts, often only some of the optical packets can go smoothly. After the exchange is completed, other parts of the optical packets cannot be exchanged, which reduces the quality of the optical packet exchange.

Contents of the invention

In order to improve the quality of the bandwidth provided by the optical switch, for example, improve the quality of optical packet switching by the optical switch, this application shows an optical switch and a data communication system.

In a first aspect, this application shows an optical switch, which includes:

P switching modules; P includes the number of wavelength types of optical packets that the optical switch supports switching; each switching module includes F switching links; P and F are both positive integers;

The switching link includes: a splitter, an aggregator, F cache groups, and schedulers corresponding to each cache group; the cache group includes multiple cache blocks;

The splitter in the switching link is used to receive an input optical signal and separate the input optical signal into optical packets of each wavelength. For any wavelength, determine the optical packet for outputting the wavelength in P switching modules. The switching module, and stores the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module;

The scheduler corresponding to any cache group in the switching link is used to schedule one of the optical packets of the wavelength in the cache group to the aggregator in the switching link;

The aggregator in the switching link is used to aggregate the optical packets of each wavelength respectively scheduled by each scheduler in the switching link into an output optical signal, and output the output optical signal.

In an optional implementation, the diverter includes:

Separator, switch controller, label extractor corresponding to each wavelength, and optical switch corresponding to each wavelength;

The separator is used to receive the input optical signal, separate the input optical signal into optical packets of each wavelength, and for any wavelength, input the optical packet of the wavelength to the label extractor corresponding to the wavelength;

The label extractor corresponding to the wavelength is used to extract the optical packet header and the optical packet load in the optical packet of the wavelength, and transfer the optical packet header to the switch controller, and transfer the optical packet load to the optical switch corresponding to the wavelength;

The switch controller is configured to determine a switching module for outputting optical packets of the wavelength among the P switching modules according to the optical packet head, and send a cache instruction to the optical switch corresponding to the wavelength; the cache instruction Used to instruct to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module;

The optical switch corresponding to the wavelength is configured to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module according to the caching instruction.

In an optional implementation, the cache group corresponding to the wavelength includes multiple cache blocks, and different cache blocks respectively correspond to different switching links among the switching links included in the P switching modules;

The cache instruction is used to instruct to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module and in the cache block corresponding to the switching link;

The optical switch corresponding to the wavelength is configured to, according to the caching instruction, in the cache group corresponding to the wavelength in one of the switching links in the determined switching module, in the cache block corresponding to the switching link. Light packets of the wavelength are stored.

In an optional implementation, the cache block includes a delayed feedback optical cache.

In an optional implementation, the delayed feedback optical cache includes:

A first optical splitter, a first combiner, a second optical splitter, a second combiner, a controller, a first optical amplifier, a second optical amplifier, a third optical amplifier, a fourth optical amplifier and an optical fiber delay line loop;

The input end of the first optical splitter is connected to the output end of the optical fiber delay line loop;

The output end of the first optical splitter is connected to the input end of the first optical amplifier and the input end of the second optical amplifier respectively;

The output end of the first optical amplifier is connected to the input end of the first combiner,

The output end of the second optical amplifier is connected to the input end of the second combiner;

The output end of the first combiner is connected to the input end of the optical fiber delay line loop;

a second optical splitter configured to receive optical packets of said wavelength;

The output end of the second optical splitter is connected to the input end of the third optical amplifier and the input end of the fourth optical amplifier respectively;

The output end of the third optical amplifier is connected to the input end of the first combiner,

The output end of the fourth optical amplifier is connected to the input end of the second combiner;

The output terminal of the second combiner is connected to the output terminal of the scheduler;

The scheduler is used to control the first optical amplifier, the second optical amplifier, the third optical amplifier and the fourth optical amplifier to turn on or off according to the controller.

In an optional implementation, the storage space of the cache block is determined based on at least L _d , L and r;

L _d includes: the maximum number of bits of optical packets that can be carried simultaneously on the link between an input end of the optical switch and the sending device that inputs the optical signal;

L includes the number of bits of the optical packet;

r includes the rate at which the optical switch switches optical packets.

In an optional implementation, the storage space of the cache block is less than or equal to (4+2*L _d /Lr)*L.

In an optional implementation, the number of delayed feedback optical buffers is determined based on L _d and L;

L includes the number of bits of the optical packet.

In an optional implementation, the number of delayed feedback optical buffers is less than or equal to 4+2*L _d /L.

In an optional implementation manner, when there are more than two delayed feedback optical buffers, the two or more delayed feedback optical buffers are connected in series.

In a second aspect, this application shows a data communication system, which includes:

At least one data center;

The data center includes at least one terminal, a photoelectric conversion device that is communicatively connected to the at least one terminal, and an optical switch as described in the first aspect. The at least one terminal communicates with the input end of the optical switch through the photoelectric conversion device. connect.

Compared with the existing technology, this application includes the following advantages:

Each switching link in the optical switch in this application has a cache group respectively. For any switching link, if at least two optical packets that need to be output through the switching link in a time slot have the same wavelength, then Cache other optical packets except one of the optical packets in the buffer group in the switching link, output the one optical packet in the time slot, and then schedule the other optical packets buffered in the buffer group in the subsequent time slot. Light grouping and output can avoid conflicts.

Secondly, the structure of the optical switch in this application can support flow fair queuing scheduling (FFQ, Flow Fair Queuing) scheduling of optical packets, and can be scheduled using a scheduler close to the output end in the switching link, so that it can be scheduled based on a simple Scheduling can be implemented using scheduling logic, and the complexity can be reduced to O(logN), which can simplify the complexity of the entire optical switch.

In addition, since the structure of the optical switch in this application can support FFQ scheduling of optical packets, and FFQ retrieval can be ideal scheduling based on Generalized Processing Sharing (GPS), broadband guarantee can be achieved, for example , can improve the throughput of the optical switch for optical packet switching, so as to improve the quality of the optical switch for optical packet switching and obtain service quality assurance.

Description of drawings

Figure 1 is a structural block diagram of an optical switch in this application.

Figure 2 is a structural block diagram of a delayed feedback optical buffer of the present application.

Figure 3 is a structural block diagram of a delayed feedback optical buffer according to the present application.

Detailed ways

In order to make the above objects, features and advantages of the present application more obvious and understandable, the present application will be described in further detail below in conjunction with the accompanying drawings and specific implementation modes.

The solution of this application can be applied to optical communication scenarios.

Optical packet switching is a packet switching method often used in optical communication scenarios. Data in optical communication scenarios is often represented by optical packets. Optical packets can also be called optical packets. Optical packets include optical packet headers and optical packet loads. Optical switches can be used for optical packet switching. The optical packet header may include information such as the source address, destination address, survival time and lifetime of the optical packet.

Optical packet switching is usually performed by optical switches. Optical switches do not need to perform photoelectric-to-electrical-optical conversion of optical signals, but can directly switch optical signals. They can include Fast Optical Switches, etc. Optical packet switching can improve network bandwidth resource utilization due to dynamic sharing and statistical multiplexing of bandwidth resources, and makes the network highly flexible.

In optical communication scenarios, optical switches usually forward optical packets directly, which easily causes optical packet switching conflicts.

For example, an input port of an optical switch can receive optical packets sent by a device in the data center and transmit the optical packet to an output port. Output ports output optical packets to destination devices in the data center. When multiple input ports of an optical switch transmit optical packets to the same output port at the same time, some optical packets may not reach the output port, causing optical packet switching conflicts. Although the retransmission mechanism can be used to retransmit optical packets when optical packet switching conflicts (that is, the controller of the optical switch sends flow control information to each device to inform each device of the failure to transmit the optical packet, so that the device can retransmit the optical packet in the next time slot. The optical packet is transmitted), however, the retransmission mechanism will lead to low throughput of the optical switch and low switching quality of the optical packet.

In order to improve the switching quality of optical packets, referring to Figure 1, an optical switch according to the present application is shown. The optical switch includes:

P switching modules. P includes the number of types of wavelengths that the optical switch supports for switching optical packets. Each switching module includes F switching links. P and F are both positive integers.

For example, the wavelengths of optical packets supported by the optical switch include λ ₁ to λ _P . The wavelengths λ ₁ to λ _P include a total of P wavelengths.

P switching modules can be parallel.

Switching links in the same switching module can be parallel.

For any switching link in any switching module, the switching link may include: a splitter, an aggregator, F cache groups, and schedulers corresponding to each cache group. A cache group contains multiple cache blocks.

The switching link has an output and an input.

The input of the switching link includes the input of a tap in the switching link.

The output of the switching link includes the output of an aggregator in the switching link.

Aggregators can include: Arrayed Wavelength Grating (AWG, Arrayed Wavelength Grating), etc.

The input end of the switching link is connected to one data center, and the output end of the switching link is connected to another data center.

The same goes for every switch link in every other switch module.

In this way, optical switches can perform optical packet switching between two data centers.

The data center can include multiple devices, that is, the data center can be regarded as a network cluster. The devices include: devices capable of optical communication with optical switches and capable of sending and receiving optical signals. For example, the devices may include: top-of-rack switches (ToR , Top of Rack Switch) or server or terminal, etc.

Wherein, for any switching link in any switching module, the splitter in the switching link is used to receive the input optical signal and separate the input optical signal into optical packets of each wavelength.

For example, the input optical signal may include multiple optical packets of different wavelengths, and the multiple different wavelengths are wavelengths of optical packets that the optical switch supports switching.

For any wavelength, the splitter in the switching link is also used to determine the switching module for outputting optical packets of this wavelength among the P switching modules, and in one of the switching links among the determined switching modules The optical packets of this wavelength are stored in the cache group corresponding to this wavelength.

In this application, for P switching modules, different switching modules use different wavelengths for output optical packets.

For example, a switching module is used to output optical packets of F different wavelengths. The switching module 1 is used to output optical packets with wavelengths λ ₁ to λ _F , the switching module 2 is used to output optical packets with wavelengths λ _F+1 to λ _2F , and the switching module 3 is used to output optical packets with wavelengths λ _2F+1 to λ _3F . Packet... By analogy, the switching module P is used to output optical packets with wavelengths λ _N-F+1 ~ λ _N.

The scheduler corresponding to any buffer group in the switching link is used to schedule one of the optical packets of the wavelength in the buffer group to the aggregator in the switching link.

The switching link supports outputting one optical packet of this wavelength in one time slot, but does not support outputting two different optical packets of this wavelength in one time slot at the same time. In this way, any buffer group in the switching link corresponds to The scheduler is used to schedule one of the optical packets of the wavelength in the buffer group to the aggregator in the switching link, so that the aggregator outputs the one of the optical packets.

The aggregator in the switching link is used to aggregate the optical packets of each wavelength respectively scheduled by each scheduler in the switching link into output optical signals, and output the optical signals.

In one embodiment of the present application, the diverter includes:

Splitter, switch controller, label extractor (LE, Label Extractor) corresponding to each wavelength, and optical switch (OS, Optical Switch) corresponding to each wavelength.

Optical switches may include 1*F optical switches.

Separators include AWG etc.

In one example, there are P label extractors, corresponding to P different optical packets that the optical switch supports switching. wavelength (such as λ ₁ ~ λ _P , etc.).

The input end of the splitter includes the input end of the splitter, and the splitter includes P output ends. The P output ends are respectively connected to the input ends of the tag extractors corresponding to different wavelengths (for example, P are respectively connected to the input ends of the tag extractors corresponding to different wavelengths). input to the tag extractor).

The output terminals of the tag extractors corresponding to different wavelengths are respectively connected to the input terminals of the optical switches corresponding to different wavelengths.

In addition, for the switching link in the switching module mentioned above, the splitter in the switching link includes a switch controller.

The switch controller includes N input terminals and N output terminals, and N is equal to F*P.

The N input terminals of the switch controller are respectively connected to the output terminals of the label extractors corresponding to one of the wavelengths in the F switching links (a total of F switching links) included in the P switching modules.

The one wavelength is one of a plurality of different wavelengths used by the switching module to output optical packets.

The N output terminals of the switch controller in different switching links in the switching module are connected to different wavelengths in the F switching links respectively included in the P switching modules (a total of F switching links). The output of the tag extractor.

An optical switch corresponding to any one of the optical switches corresponding to each wavelength in the splitter.

The optical switch has F output terminals, and the F output terminals are respectively connected to buffer groups corresponding to the wavelength in the F switching links in the switching modules of the P switching modules for outputting optical packets of the wavelength. The input terminals are connected one by one.

The optical switch can be a 1*F switch, that is, F output terminals, of which F-1 output terminals can be turned off, and one of the output terminals can be turned on, so that the optical packet of this wavelength can be transmitted to the turned on output. The input end of the cache group corresponding to the wavelength in the switching link (a total of F switching links) connected to the end, so as to store the optical packet of the wavelength in the open output end. The input end of the connection is the switching link. , in the cache group corresponding to this wavelength.

Which output end of the optical switch is turned on and which output end is turned off can be controlled by the switch controller.

For example, it can be controlled by an off switch controller at least based on the optical packet header of the optical packet.

The splitter in the splitter in each switching link in this application is used to receive the input optical signal and split the input optical signal into optical packets of various wavelengths.

The splitter may include an AWG, and the AWG may include a 1×P AWG. The 1×P AWG is used to split the physical link into p wavelength channels, respectively denoted as λ ₁ wavelength channel, λ ₂ wavelength channel... and λ _p Wavelength channel, so that the input optical signal can be separated into optical packets of p different wavelengths, for example, optical packets of wavelength λ ₁ , optical packets of wavelength λ ₂ ... and optical packets of wavelength λ _p , etc.

The aggregator in this application may include an AWG, and the AWG may include a 1×F AWG.

A 1×F AWG (aggregator) is used to aggregate F wavelength channels into a physical link.

For example, the 1×F AWG (aggregator) in each switching link in switching module 1 is used to aggregate the wavelength channels from λ ₁ to λ _F into one physical link, and the 1×F AWG (aggregator) in each switching link in switching module 2 The 1×F AWG (aggregator) is used to aggregate the wavelength channels from λ _F+1 to λ _2F into another physical link...and the 1×F AWG (Aggregator) in each switching link in the switching module P Aggregator) is used to aggregate the wavelength channels from λ _N-F+1 to λ _N into another physical link, etc.

In this way, it can be realized that the 1×F AWG (aggregator) in each switching link in the switching module 1 is used to aggregate the optical packets from λ ₁ to λ _F into an output optical signal, and output the aggregated output optical signal. , the 1×F AWG (aggregator) in each switching link in the switching module 2 is used to aggregate the optical packets from λ _F+1 to λ _2F into an output optical signal, and output the aggregated output optical signal, ...and the 1×F AWG (aggregator) in each switching link in the switching module P is used to aggregate the optical packets from λ _N-F+1 to λ _N into an output optical signal, and output the aggregated Output optical signals, etc.

Through this application, the conflict of AWG on the output side can be avoided.

For example, for any switching link in any switching module, there are F schedulers in the switching link, corresponding to different wavelengths, and the F schedulers schedule to the aggregator in the switching link respectively. The wavelengths of the optical packets are different. In this way, the wavelengths of each optical packet obtained by the aggregator in the switching link are different (there will not be more than two optical packets in each optical packet obtained by the aggregator in the switching link). The wavelengths are the same), for example, F different optical packets can be obtained, etc., the F different optical packets can be aggregated into an output optical signal, and the output optical signal can be output. In this way, the occurrence of two optical packets with the same wavelength can be avoided. The above optical packets collide in the same time slot in the aggregator of the same switching link.

In one embodiment of the present application, for any switching link in any switching module, after the splitter in the switching link separates the input optical signal into optical packets of multiple wavelengths, for any wavelength, the The splitter in the switching link is used to input the separated optical packets of the wavelength to the label extractor corresponding to the wavelength.

The tag extractor corresponding to the wavelength is used to extract the optical packet head and the optical packet load in the optical packet of the wavelength, and transfer the optical packet head to the switch controller, and transfer the optical packet load to the optical packet corresponding to the wavelength. switch.

The switch controller is configured to determine, among the P switching modules, a switching module for outputting optical packets of the wavelength according to the optical packet header, and send a cache instruction to the optical switch corresponding to the wavelength. The cache instruction is used to instruct to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module.

The optical switch corresponding to the wavelength is used to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module according to the cache instruction.

In one embodiment of the present application, for any switching link in any switching module, and for any wavelength, the cache group corresponding to the wavelength in the switching link includes multiple cache blocks, and different caches The blocks respectively correspond to different switching links among the switching links respectively included in the P switching modules.

That is, different cache blocks among the multiple cache blocks included in the cache group corresponding to the wavelength in the switching link are used to store different cache blocks in the F switching links respectively included in the P switching modules. The optical packets of this wavelength obtained by the exchange link.

In this way, the cache instruction may be used to instruct the optical packet of the wavelength to be stored in the cache group corresponding to the wavelength in one of the switching links in the determined switching module and in the cache block corresponding to the switching link.

Correspondingly, the optical switch corresponding to the wavelength is used to store the cache block corresponding to the switching link in the cache group corresponding to the wavelength in one of the switching links in the determined switching module according to the caching instruction. Light of that wavelength is grouped.

In another embodiment of the present application, the cache block includes a delayed feedback optical cache.

Referring to Figure 2, delayed feedback optical buffer includes:

The first optical splitter, the first combiner, the second optical splitter, the second combiner, the controller, the first optical amplifier, the second optical amplifier, the third optical amplifier, the fourth optical amplifier and the fiber delay line loop Fiber Delay Line Circulation Loop.

The input end of the first optical splitter is connected to the output end of the optical fiber delay line loop.

The output end of the first optical splitter is connected to the input end of the first optical amplifier and the input end of the second optical amplifier respectively.

The output terminal of the first optical amplifier is connected to the input terminal of the first combiner.

The output terminal of the second optical amplifier is connected to the input terminal of the second combiner.

The output end of the first combiner is connected to the input end of the optical fiber delay line loop.

The second optical splitter is used to receive light packets of this wavelength.

The output end of the second optical splitter is connected to the input end of the third optical amplifier and the input end of the fourth optical amplifier respectively.

The output terminal of the third optical amplifier is connected to the input terminal of the first combiner.

The output terminal of the fourth optical amplifier is connected to the input terminal of the second combiner.

The output of the second combiner is connected to the output of the scheduler.

The scheduler is used to control the turning on or off of the first optical amplifier, the second optical amplifier, the third optical amplifier and the fourth optical amplifier according to the controller (not shown in the figure).

In the delayed feedback optical buffer shown in Figure 2, the optical packet is input from the input end of the second optical splitter. If the controller controls the third optical amplifier to turn off and the fourth optical amplifier to turn on, the optical packet flows to the second optical splitter. The combiner is output to the outside of the cache block via the second combiner, for example, to the scheduler via the second combiner.

If the controller controls the fourth optical amplifier to be turned off and the third optical amplifier to be turned on, the optical packet flows to the first combiner and is output to the optical fiber delay line loop through the first combiner (to implement the delay feedback type optical cache). buffered optical packets) and then looped to the input of the first optical splitter in the buffer block.

If the controller controls the first optical amplifier to turn on and the second optical amplifier to turn off, the optical packet flows to the first combiner again, and is output to the fiber delay line loop through the first combiner (to realize the delay feedback type optical cache). Continue to cache optical packets in the cache block), and then loop to the input end of the first optical splitter in the cache block.

If the controller controls the second optical amplifier to turn on and the first optical amplifier to turn off, the optical packet flows to the second combiner and is output to the outside of the buffer block through the second combiner (the optical packet is no longer buffered in the delayed feedback optical buffer). packet), for example, output to the scheduler via the second combiner.

It should be noted that Figure 2 is only an example of one form of delayed feedback optical buffer in this application. Other forms of delayed feedback optical buffer can also be used, and this application is not limited to this.

In another embodiment of the present application, the storage space of the cache block is determined based on at least L _d , L and r.

L _d includes: the maximum number of bits of optical packets that can be carried simultaneously on the link between an input end of the optical switch and the sending device that inputs the optical signal. The unit of length may include the number of bits (such as Byte or bit, etc.).

L includes the number of bits of the optical packet.

r includes the rate at which the optical switch switches optical packets.

For example, the storage space of the cache block is less than or equal to (4+2*L _d /Lr)*L.

In this application, the number of bits of each optical packet may be the same, for example, L.

The maximum number of bits of optical packets that can be carried simultaneously on the link can be understood as: the maximum number of bits of optical packets that can be transmitted simultaneously on the link.

For example, assuming that the link between an input end of the optical switch and the sending device that inputs the optical signal can carry 10 optical packets at the same time, L _d can be 10L.

Or, assuming that the maximum number of bits that can be carried simultaneously on the link between an input end of the optical switch and the sending equipment that inputs the optical signal is 10L (L _d ), then one input end of the optical switch and the sending equipment that inputs the optical signal The link between them can carry 10 optical packets at the same time, for example, it can transmit 10 optical packets at the same time.

In another embodiment of the present application, the number of delayed feedback optical buffers is determined based on L _d and L .

L includes the number of bits of the optical packet.

For example, the number of delayed feedback optical buffers is less than or equal to 4+2*L _d /L.

In one embodiment, when there are more than two delayed feedback optical buffers, the two or more delayed feedback optical buffers are connected in series. For example, referring to FIG. 3 , the output end of the second combiner in the previous delayed feedback optical buffer is connected to the input end of the second optical splitter in the adjacent delayed feedback optical buffer.

Among them, the goal of FFQ scheduling is to pursue the service volume received by the optical packet flow to be consistent with the service volume received in the ideal GPS scheduling.

In GPS scheduling, the service volume W _ij obtained by the cached optical packet flow f _ij is not less than the ratio of its rate to the rate of the unbuffered optical packet flow, and the relationship is as follows:

Then for optical packets with a fixed number of bits, in actual packet scheduling, the time when FFQ completes the service will not be one time slot later than the ideal GPS scheduling. W _FFQ (0,t) and W _GPS (0,t) respectively represent FFQ scheduling. With the scheduling amount of GPS scheduling in [0,t] time, we can get formula (1):
-L≤W _FFQ (0,t)-W _GPS (0,t)≤(1-r _i,j )L (1)

Assume that the input port of switching link i of the optical switch is connected to device i in the data center.

The distance between equipment i to equipment N and the optical switch is all d.

Let the optical packet flow from equipment i in one data center to equipment j in another data center be f _i,j , that is, the optical packet flow from input port i to output port j of the optical switch is f _i,j .

For device i, consider an optical packet with a fixed number of bits L.

remember and are the transmission volumes from MB and EB in time period (0,t) under GPS scheduling respectively.

remember and are the transmission volumes transmitted from MB and EB in time period (0,t) under FFQ scheduling respectively.

MB (Micro-Buffer, micro-buffer) is the cache block in the cache group in the switching link in the optical switch.

EB (Electric-Buffer, electrical buffer) is the electrical buffer in device i.

For optical switches, in the time interval [0,t], assume that queue MB _i,j is empty at time s. In the time period [s,t] based on ideal scheduling GPS, MB _i,j is not empty continuously. If MB _{i and j} are empty at time t, then let s=t.

Formula (2) can be obtained by simulating the characteristics of GPS fluid scheduling through FFQ group scheduling:

Since MB _i,j is empty before time s, and continues to be not empty under GPS scheduling after time s, all optical packets arriving at time s have been scheduled away, and a new optical packet has arrived at time s. Packet, let L _d be the maximum number of bits of optical packets that can be carried simultaneously on the link between an input end of the optical switch and the sending device that inputs the optical signal, then formula (3) can be obtained:

With the FFQ scheduling characteristics, we can get formula (4) and formula (5):

Combining the above equations, we can get formula (6):

It is known that within the (s, t) time period, the cache block is not empty continuously under GPS scheduling, so we can get formula (7):

Then we can get formula (8):

Combining formulas (4) and (5), we can get formula (9):

That is, the cache upper limit of MB _i,j can be (4+2*L _d /Lr)*L.

Through this application, the maximum cache size of MB _i,j only needs to be (4+2*L _d /Lr)*L to meet the switching quality of optical packets as much as possible. There is no need for larger cache capacity and the hardware can be reduced. cost.

And the maximum number of delayed feedback optical buffers only needs to be 4+2*L _d /L to meet the switching quality of optical packets as much as possible. There is no need for more delayed feedback optical buffers, which can reduce hardware costs. .

Secondly, the structure of the optical switch in this application can support FFQ scheduling of optical packets, and can be scheduled using a scheduler close to the output end in the switching link. In this way, scheduling can be achieved based on simple scheduling logic, and the complexity can be reduced. To O(logN), the complexity of the entire optical switch can be simplified.

In addition, since the structure of the optical switch in this application can support FFQ scheduling of optical packets, and FFQ retrieval can be ideal scheduling based on GPS, broadband guarantee can be achieved. For example, the efficiency of the optical switch in switching optical packets can be improved. Throughput to improve the quality of optical packet switching by optical switches and obtain service quality assurance.

In addition, this application also shows a data communication system. The data communication system includes:

At least one data center. The data center includes at least one terminal, a photoelectric conversion device that is communicatively connected to the at least one terminal, and an optical switch as in the previous embodiment. The at least one terminal is communicatively connected to the input end of the optical switch through the photoelectric conversion device.

Each embodiment in this specification is described in a progressive manner. Each embodiment focuses on its differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other.

Embodiments of the present application are described with reference to flowcharts and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the present application. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable information processing terminal equipment to produce a machine such that the instructions are executed by the processor of the computer or other programmable information processing terminal equipment. Means are generated for implementing the functions specified in the process or processes of the flowchart diagrams and/or the block or blocks of the block diagrams.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable information processing terminal equipment to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction means, the The instruction means implements the functions specified in a process or processes of the flowchart and/or a block or blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable information processing terminal equipment, so that a series of operating steps are executed on the computer or other programmable terminal equipment to produce computer-implemented processing, thereby causing the computer or other programmable terminal equipment to perform computer-implemented processing. The instructions executed on provide steps for implementing the functions specified in a process or processes of the flow diagrams and/or a block or blocks of the block diagrams.

Although preferred embodiments of the embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once the basic inventive concepts are understood. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

Finally, it should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or any such actual relationship or sequence between operations. Furthermore, the terms "comprises,""comprises," or any other variation thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or end device that includes a list of elements includes not only those elements, but also elements not expressly listed or other elements inherent to such process, method, article or terminal equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article or terminal device including the stated element.

The optical switch and data communication system provided by the present application have been introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the present application. The method and its core idea; at the same time, for those of ordinary skill in the field, there will be changes in the specific implementation and application scope based on the ideas of this application. In summary, the contents of this specification should not be understood as Limitations on this Application.

Claims

An optical switch, characterized in that the optical switch includes:

P switching modules; P includes the number of wavelength types of optical packets that the optical switch supports switching; each switching module includes F switching links; P and F are both positive integers;

The switching link includes: a splitter, an aggregator, F cache groups, and schedulers corresponding to each cache group; the cache group includes multiple cache blocks;

The splitter in the switching link is used to receive an input optical signal and separate the input optical signal into optical packets of each wavelength. For any wavelength, determine the optical packet for outputting the wavelength in P switching modules. The switching module, and stores the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module;

The scheduler corresponding to any cache group in the switching link is used to schedule one of the optical packets of the wavelength in the cache group to the aggregator in the switching link;

The aggregator in the switching link is used to aggregate the optical packets of each wavelength respectively scheduled by each scheduler in the switching link into an output optical signal, and output the output optical signal.
The optical switch according to claim 1, characterized in that the splitter includes:

Separator, switch controller, label extractor corresponding to each wavelength, and optical switch corresponding to each wavelength;

The separator is used to receive the input optical signal, separate the input optical signal into optical packets of each wavelength, and for any wavelength, input the optical packet of the wavelength to the label extractor corresponding to the wavelength;

The label extractor corresponding to the wavelength is used to extract the optical packet header and the optical packet load in the optical packet of the wavelength, and transfer the optical packet header to the switch controller, and transfer the optical packet load to the optical switch corresponding to the wavelength;

The switch controller is configured to determine a switching module for outputting optical packets of the wavelength among the P switching modules according to the optical packet head, and send a cache instruction to the optical switch corresponding to the wavelength; the cache instruction Used to instruct to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module;

The optical switch corresponding to the wavelength is configured to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module according to the caching instruction.
The optical switch according to claim 2, characterized in that the cache group corresponding to the wavelength includes a plurality of cache blocks, and different cache blocks correspond to different switches in the switch links respectively included in the P switch modules. link;

The cache instruction is used to instruct to store the optical packet of the wavelength in the cache group corresponding to the wavelength in one of the switching links in the determined switching module and in the cache block corresponding to the switching link;

The optical switch corresponding to the wavelength is configured to, according to the caching instruction, in the cache group corresponding to the wavelength in one of the switching links in the determined switching module, in the cache block corresponding to the switching link. Light packets of the wavelength are stored.
The optical switch according to claim 3, wherein the buffer block includes a delayed feedback optical buffer.
The optical switch according to claim 4, the delayed feedback optical buffer includes:

A first optical splitter, a first combiner, a second optical splitter, a second combiner, a controller, a first optical amplifier, a second optical amplifier, a third optical amplifier, a fourth optical amplifier and an optical fiber delay line loop;

The input end of the first optical splitter is connected to the output end of the optical fiber delay line loop;

The output end of the first optical splitter is connected to the input end of the first optical amplifier and the input end of the second optical amplifier respectively;

The output end of the first optical amplifier is connected to the input end of the first combiner;

The output end of the second optical amplifier is connected to the input end of the second combiner;

The output end of the first combiner is connected to the input end of the optical fiber delay line loop;

a second optical splitter configured to receive optical packets of said wavelength;

The output end of the second optical splitter is connected to the input end of the third optical amplifier and the input end of the fourth optical amplifier respectively;

The output end of the third optical amplifier is connected to the input end of the first combiner;

The output end of the fourth optical amplifier is connected to the input end of the second combiner;

The output terminal of the second combiner is connected to the output terminal of the scheduler;

The scheduler is used to control the first optical amplifier, the second optical amplifier, the third optical amplifier and the fourth optical amplifier to turn on or off according to the controller.
The optical switch according to claim 4, characterized in that the storage space of the cache block is determined based on at least Ld , L and r;

L d includes: the maximum number of bits of optical packets that can be carried simultaneously on the link between an input end of the optical switch and the sending device that inputs the optical signal;

L includes the number of bits of the optical packet;

r includes the rate at which the optical switch switches optical packets.
The optical switch according to claim 6, wherein the storage space of the cache block is less than or equal to (4+2*L d /Lr)*L.
The optical switch according to claim 4, wherein the number of delayed feedback optical buffers is determined based on L d and L;

L d includes: the maximum number of bits of optical packets that can be carried simultaneously on the link between an input end of the optical switch and the sending device that inputs the optical signal;

L includes the number of bits of the optical packet.
The optical switch according to claim 8, wherein the number of delayed feedback optical buffers is less than or equal to 4+2*L d /L.
The optical switch according to claim 4, wherein when there are more than two delayed feedback optical buffers, the two or more delayed feedback optical buffers are connected in series.
A data communication system, characterized in that the data communication system includes:

At least one data center;

The data center includes at least one terminal, a photoelectric conversion device that is communicatively connected to the at least one terminal, and an optical switch according to any one of claims 1 to 10. The at least one terminal communicates with the optical switch through the photoelectric conversion device. Communication connection between input terminals.