CN1633104A - Optical Label Switching Fabric Supporting Blocking Mode and Multiplexing Control - Google Patents

Abstract

This invention relates to a mode of supporting block and an optical mark exchange structure controlled by multi-path multiplex. A computer end is connected with the exchange marginal nodes of optical mark, which are connected with the exchange core nodes, an electronic input/output wire card is connected into an optical packet bundle and de-packet processor, which is connected with light mark head generation module and a WDM device, in the core nodes, the input of WDM device connects the fibers arriving at the core nodes with the input of a light mark T-R processor and a light switch exchange matrix, the output of the processor and the matrix are connected with the output of the WDM device.

Description

Optical Label Switching Fabric Supporting Blocking Mode and Multiplexing Control

technical field

The invention relates to a network structure used in the technical field of optical communication, in particular to an optical label switching structure supporting blocking mode and multiplexing control.

Background technique

Optical switching can be divided into two modes: circuit switching and optical packet switching of wavelength routing. The optical switching mode of the former is circuit switching, the basic switching unit is a call, and the bandwidth of the entire call is reserved in both directions. The main defect of this switching method is that the wavelength routing channel must be established before data transmission, and the channel wavelength is always occupied and released until it is completed. A more ideal optical switching method is of course optical packet switching. It divides the optical information into optical load groups with a fixed length, and then adds optical headers carrying routing information to form optical information packets with a fixed format, that is, optical packets, for transmission. The optical packet switching technology directly implements small-grained packet switching on the optical layer, which has the advantages of small overhead, high bandwidth utilization, and transparency to the format of the transmitted information. In recent years, some progress has been made. Packet switching technology. In the multi-wavelength optical label switching technology, the optical packet header is composed of several optical pulses with different wavelengths, and different combinations of these optical pulses represent different routing information. The wavelength of the optical pulse of the optical packet header and the carrier wave of the optical load in the optical packet belong to the same wavelength channel, and do not occupy additional wavelength resources. At the switching node, the optical wave routing is realized by judging the combination of different wavelengths of the packet head optical pulse.

Through literature retrieval of prior art, it is found that "Realization of Multi-wavelength Label" published by Shilin Xiao et al. in "IEEE Photonics Technology Letters" (Institute of Electrical and Electronics Engineers Photon Technology Letters) 2003, 15(4): 605-607 "Optical Packet Switching" (realization of multi-wavelength label optical packet switching), mentioned in this article is only the simplest optical label switching system, which cannot perform real-time terminal control on optical packets, cannot distinguish priority service classes at edge nodes, and cannot Completing the packaging and unpacking of optical packets and the addition of optical marking headers for arbitrary data streams, as well as complex functions such as programmable optical marking and optical packet time and optical packet interval delay, which severely limits the intelligence and flexibility of optical label switching, and even affects The real-time nature of the entire optical label switching system leads to the paralysis of the optical label switching network.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, to provide an optical label switching structure that supports blocking mode and multiplexing control, by introducing an independent data flow control mechanism between computer terminals and optical label switching edge nodes, It enables it to complete the packetization and unpacking of optical Ethernet packets based on priority distinction and the programmable delay control of optical packets in the two modes of blocking mode and multiplexing of optical label switching edge nodes, so as to ensure that optical packets are realized at the core node of optical label switching Based on microsecond-level switching and control, the performance of the entire optical label switching network is improved.

The present invention is realized through the following technical solutions, and the present invention includes: an optical label switching edge node, an optical label switching core node, and a computer terminal. The switching edge node is connected to the optical label switching core node through an optical fiber, and the optical label switching core node is interconnected with the optical label switching core node through an optical fiber.

The optical label switching edge node structure is divided into four parts: electronic input and output line card, optical packet packing and unpacking processor, optical label head generation module and wavelength division multiplexer. The video terminal service flow is connected to the optical packet packaging and unpacking processor through the electronic input and output line card, and the optical packet packaging and unpacking processor is connected with the optical marking head generating module and the wavelength division multiplexer at the same time, and then the optical marking head generating module outputs The optical signal is connected to the wavelength division multiplexer through the optical fiber and the optical packet sending and receiving of the optical packet packing and unpacking processor, and the wavelength division multiplexer is connected to the optical label switching core node through the optical fiber.

The optical label switching core node structure is divided into four parts: input wavelength division multiplexer, optical label transceiver processor, optical switch matrix and output wavelength division multiplexer. The input wavelength division multiplexer connects the optical fiber reaching the core node of the optical label switch to the input of the optical label transceiver processor and the input of the optical switch matrix to separate the optical label head and the payload of the optical packet, and connects the output of the optical label transceiver processor to the output of the optical switch matrix The output wavelength division multiplexer multiplexes the newly generated optical label head and the exchanged optical packet payload, and then connects to the optical label switching network through the optical fiber.

The computer terminal and the optical packet packaging and unpacking processor, in the case of video recording, the computer terminal encapsulates the data, delay and terminal address into the data packet and transmits it to the optical label switching edge node optical packet packaging and unpacking processor. The computer terminal under the multimedia video stream can send a separate control packet, and the optical packet packing and unpacking processor processes the terminal control information in the blocking mode and the multiplexing mode, and controls the attributes of the optical packet delay, destination address, and service priority in real time. The computer terminal realizing independent data control and the optical label switching edge node optical packet packaging and unpacking processor are important features of the present invention.

Based on the above structural features, the present invention captures low-speed cameras of multiple computer terminals or outputs high-speed multimedia video streams in 10M/100M electronic Ethernet packet format to the optical label switching edge node, and the optical label switching edge node processes it in real time and packs it into a 1Gbps Optical Ethernet packets, and adding an optical marking head to each optical packet, after optical wavelength division multiplexing, enters the core optical label switching network for switching and transmission, and the optical Ethernet packet with the optical marking head is only for the optical marking head For photoelectric-optical conversion, the signal processor completes optical label recognition and control of the optical switch matrix in the electrical domain, and the optical packet is directly switched through the optical switch matrix under the drive of the control signal and then multiplexed with the updated optical label head. Fiber transport to the next optical label switching core node. After the optical packet arrives at the egress optical label switching edge node, the optical packet is demultiplexed first, and then the optical packet is packaged and unpacked by the optical label switching edge node optical packet unpacking processor to restore the optical packet to a 10M/100M electronic Ethernet packet and send it to the target computer terminal to re-display the video flow.

On the basis of the above description of the structural characteristics of the optical label switching network, further describe the internal working process and principle of the present invention between the computer terminal and the optical label switching edge node, as well as between the optical label switching edge node and the optical label switching core node:

1) In the case of a computer terminal capturing a signal with a low-speed camera, the captured camera signal is directly packaged into an electrical Ethernet packet containing delay information, source and destination terminal address information, and service priority information and converged into the optical label switching edge node connected to it. The optical label switching edge node electronic input and output line card receives the video stream from the computer terminal, and the optical packet packaging and unpacking processor performs different service aggregation queues according to the optical packet delay parameters, service priority and terminal address information carried by the electrical Ethernet packet. middle pack;

2) In the case of high-speed multimedia video stream, the computer terminal only sends a separate video stream control packet and pure video data packet to the optical label switching edge node. Based on this mechanism for receiving computer terminal control packets and data packets at optical label switching edge nodes, the present invention distinguishes them into blocking mode and multiplexing mode. The blocking mode refers to the simultaneous transmission of pure video stream data packets and video control packets To the same port of the optical label switching edge node, and the multiplexing mode is that the optical label switching edge node receives the control packet at a separate port, which reduces the reception blocking wait of the optical label switching edge node optical packet packaging and unpacking processor Time to improve input and output electronic line card port utilization. In these two modes, the control packet contains optical packet delay information, source terminal address, destination terminal address information, and business priority distinction information, so that the optical packet packaging and unpacking processor also recognizes and processes the control information received in real time, Therefore, the terminal address routing, optical packet priority and optical packet delay timing control information of the high-speed multimedia video stream packaged into optical packets can be changed in real time, and the real-time terminal high-speed video stream service aggregation and transmission can be completed.

The optical packet packaging and unpacking processor caches the above-mentioned low-speed camera capture video signal and high-speed multimedia video stream in the fast memory, uses the time timer and the two-dimensional limit of the maximum optical packet length to trigger the corresponding data queue, and overflows the optical packet queue After the conditions are satisfied, the output drive level of the optical packet packaging and unpacking processor controls the laser array to generate optical marks, and then the optical marking head and optical packets are multiplexed into the wave at strict time intervals under the precise timing of the optical packet packaging and unpacking processor timer. The demultiplexer sends out. The optical packet packaging and unpacking processor can also control the interval between two consecutive optical packets, so that the 10M/100M video Ethernet packets from the electronic input and output line cards are converted into 1G with optical marking heads after being processed by the optical label switching edge node Optical Ethernet packets enter the optical label switching core optical network. Similarly, the unpacking process of the optical label switching edge node only needs to carry out the reverse process of packaging the received optical packets, so as to forward them to the corresponding computer terminals through the electronic input and output line cards. The optical label switching core node of the optical label switching network receives the Gigabit Ethernet optical packet with the optical label switching head from the adjacent optical label switching edge node or the optical label switching core node, and separates the optical label head and the optical label through the input wavelength division multiplexer. The Ethernet payload, the optical marking head enters the optical marking transceiver processor, completes the photoelectric conversion within the interval between the optical marking head and the optical packet payload, and high-speed electronic processing generates corresponding driving electrical signals to control the optical switch switching matrix, and the optical packet payload is in Under the control of the drive circuit, the all-optical switching is transparently completed through the optical switch matrix, and the optical tag transceiver processor updates the tag information in the electrical domain to re-drive the laser to emit the optical tag, the new optical tag and the optical packet payload output by the optical switch matrix In the interval time, they are multiplexed and output to the next node through the output wavelength division multiplexer.

The invention improves the structure of the computer terminal and optical label switching edge node optical packet packaging and unpacking processor, realizes real-time terminal control of optical packets, distinguishes business class priority packaging at optical label switching edge nodes, and completes the packaging and unpacking of optical packets Packets, add optical tags for any data stream, programmable optical tag and optical packet time and optical packet interval delay and other complex functions, which greatly improve the intelligence and flexibility of optical label switching, and improve the real-time characteristics of the entire optical label switching system and extensibility features. The realization of optical packet packaging and unpacking is more conducive to the advantages of large capacity and high-speed optical switching of optical label switching network, and also reduces the blocking rate and competition of optical label switching core nodes, and optimizes network performance.

On the basis of a simple optical label switching demonstration system, the present invention designs and proposes an optical label switching structure that supports arbitrary data flow blocking mode and terminal control in multiplexing mode, and introduces an independent optical label switching structure between user terminals and edge access nodes Data flow control mechanism, so that in the two modes of optical label switching edge node blocking mode and multiplexing mode, it can complete the packetization and unpacking of optical Ethernet packets based on priority distinction and the programmable delay control of optical packets, and realize any independent data flow The access control ensures the microsecond-level switching and control of optical packets at the core node of optical label switching, improves the bandwidth utilization rate of optical label switching network, increases the intelligence of optical label switching edge nodes, and makes full use of the flexible cache of the electrical layer It improves the self-adaption ability of the network, simplifies the control and management of the core optical network, improves the performance of the entire optical label switching network and the powerful control ability for multiple service accesses, and enhances the robustness of the optical label switching network itself.

Description of drawings

Fig. 1 structure diagram of optical label switching network of the present invention

Wherein, the edge is an optical label switching edge node, and the core is an optical label switching core node.

Fig. 2 Structural diagram of optical label switching edge node (a) and optical label switching core node (b) of the present invention

The data packet format that Fig. 3 computer terminal of the present invention sends

Among them, (a) is the electronic packet format of the low-speed camera capture signal, (b) is the high-speed multimedia video stream control packet format, and (c) is the high-speed multimedia video stream pure data packet format.

Detailed ways

As shown in Figure 1, the OLS network structure of the present invention includes: a computer terminal 1, an OLS edge node 2, and an OLS core node 3, and the connection relationship is: four computer terminals 1 are connected to the OLS edge node 2 , three optical label switching core nodes 3 are interconnected, and are connected to three corresponding optical label switching edge nodes 2 at the same time, and the other two optical label switching edge nodes 2 are connected to two computer terminals 1 respectively. The low-speed camera capture signals or high-speed multimedia video streams generated by the four computer terminals 1 are aggregated in 10M/100M electrical Ethernet packet format and connected to the optical label switching edge node 2, and the video signals of the computer terminals are aggregated at the optical label switching edge node 2. The priority of the service class and the destination address are classified and packaged into Gigabit optical Ethernet packets. The optical label switching edge node 2 also adds an optical label header to each optical packet, and sends a complete optical label with the optical label header under precise delay control. The Ethernet packet arrives at the optical label switching core node 3, and the optical label switching core node 3 processes the optical label photoelectric light in real time to control the transparent exchange of the optical Ethernet payload. The electrical Ethernet packet is sent to the destination computer terminal 1 and the video is echoed.

Fig. 2 (a) provides the structural diagram of the optical label switching edge node of the present invention, the optical label switching edge node is composed of an electronic input and output line card 4, an optical packet packing and unpacking processor 5, an optical label head generating module 6 and a wavelength division multiplexing The device 7 is composed of four parts. The electronic input and output line card 4 receives the 10M/100M electrical Ethernet data packet from the computer terminal and forwards it to the optical packet packaging and unpacking processor 5, and the optical packet packaging and unpacking processor 5 assigns the video data packet according to the service priority and destination terminal address Queue to the corresponding data center queue, using the two-dimensional limit aggregation method based on threshold and time, when an optical packet packaging is completed, the optical packet packaging and unpacking processor 5 drives the optical marking head generation module 6 to emit optical marks, and at the same time passes through the optical packet After the marking head and the payload of the optical packet are strictly timed at intervals, the Gigabit optical Ethernet packet is sent and multiplexed with the optical marking head and enters the wavelength division multiplexer 7 and is output through the optical fiber. Similarly, the optical packet with the optical marking head is demultiplexed by the wavelength division multiplexer 7 at the exit node into a gigabit pure optical Ethernet data packet and sent to the optical packet packaging and unpacking processor 5, and the optical packet packaging and unpacking processor 5 follows the packaging Regular unpacking restores the data to the original 10M/100M video signal, sends it to the electronic input and output line card 4 and forwards it to the corresponding destination computer terminal. FIG. 2( b ) is a structural diagram of an optical label switching core node. The optical label switching core node is composed of an input wavelength division multiplexer 8 , an optical label transceiver processor 9 , an optical switch matrix 10 and an output wavelength division multiplexer 11 . The gigabit optical Ethernet packet carrying the optical label head of the optical label switching network enters the optical label switching core node 3 and first passes through the input wavelength division multiplexer 8 to demultiplex the optical label header and the payload of the optical packet respectively to the optical label transceiver processor 9 And the optical switch matrix 10, in the interval time between the optical marking head and the optical packet payload, the optical marking head undergoes photoelectric conversion in the optical marking transceiver processor 9 to identify and process the electronic head information and drive the optical switching matrix 10 to be set to a corresponding state, the optical packet payload arriving at this time does not need to be cached and waits to directly complete transparent optical switching in the pre-set optical switch switching matrix 10, and its output is connected to the output wavelength division multiplexer 11, and the optical label transceiver processor 9 The tag information is also updated at the same time, and the emitted optical tag is connected to the output wavelength division multiplexer 11 and then sent out after being multiplexed at an interval in advance of the payload of the optical packet.

Figure 3 shows the format of data packets and control packets transmitted between computer terminals and optical label switching edge nodes. One grid represents one byte of data. In the electronic packet format (a) of the low-speed camera capture signal, bytes 1 and 2 represent the delay value between optical Ethernet packets after the electronic video packet is packaged by the edge node, and the unit is micro Second. Byte 3 represents the destination terminal address, byte 4 represents the priority of this business class, byte 5 represents the source computer terminal address, bytes 6 and 7 are reserved for future definition, and the part of number 8 represents the video capture data payload. The computer terminal adopts this packet format in the case of low-speed camera capture signal, and the terminal sends an electrical Ethernet packet containing delay values 1 and 2, source address 5, destination terminal address 3 and business priority information 4 and converges into the optical network connected to it. The label switching edge node, the optical label switching edge node electronic input and output line card receives the video stream from the computer terminal, and the optical packet packaging and unpacking processor is in accordance with the optical packet delay value, service priority and terminal address information carried by the electrical Ethernet packet. Pack and set the optical packet timing interval in different service aggregation queues; in the high-speed multimedia video flow control packet format (b), byte 1 to byte 5 have the same meaning as (a), and byte 6 to byte 8 are reserved for use ; In the high-speed multimedia video stream pure data packet format (c), the video stream data packet 1 can be any defined pure video data. Computer terminals use separate control packets (b) and data packets (c) in the case of high-speed multimedia video streams. Based on this mechanism for receiving computer terminal control packets and data packets at optical label switching edge nodes, the present invention distinguishes them as blocking The blocking mode means that the pure video stream data packets and the video control packets are sent to the same port of the optical label switching edge node at the same time, while the multiplexing mode means that the optical label switching edge nodes send the control packets separately The port receiving, optical packet packaging and unpacking processor also recognizes and processes the control information received in real time, so as to change the terminal address routing, optical packet priority and optical packet delay timing control information of the high-speed multimedia video stream packaged into optical packets in real time, Complete the aggregation and transmission of real-time terminal high-speed video stream services.

The optical label switching structure proposed by the present invention has received good results in actual tests. The terminal low-speed camera capture signal and high-speed multimedia video stream are packaged and unpacked through the optical label switching network echoed by timing control, and the video flow is smooth and the video quality is good. The next step of research work can be based on this programmable packing and unpacking multi-node network structure, adding fiber delay lines, wavelength converters, and using deflection routing to fully study the characteristics of the advanced technology of optical label switching and the performance of optical label switching networks.

Claims (4)

1. An optical label switching structure supporting blocking mode and multiplexing control, comprising: a computer terminal (1), an optical label switching edge node (2) and an optical label switching core node (3), characterized in that the optical label The switching edge node (2) is composed of an electronic input and output line card (4), an optical packet packing and unpacking processor (5), an optical marking head generating module (6) and a wavelength division multiplexer (7), and the electronic input and output line The card (4) is connected to the optical packet packaging and unpacking processor (5), and the optical packet packaging and unpacking processor (5) is connected with the optical marking head generation module (6) and the wavelength division multiplexer (7) simultaneously, and then The output optical signal of the optical marking head generation module (6) is connected to the wavelength division multiplexer (7) through the optical fiber and the optical packet packaging and unpacking processor (5) together with the optical packet transceiver, and the wavelength division multiplexer (7) is connected to the wavelength division multiplexer (7) through the optical fiber. The optical label switching core node (3) is connected, and the optical label switching core node (3) is composed of an input wavelength division multiplexer (8), an optical label transceiver processor (9), an optical switch matrix (10) and an output wavelength division multiplexer Composed of a device (11), the input wavelength division multiplexer (8) connects the optical fiber reaching the optical label switching core node (3) to the input of the optical label transceiver processor (9) and the input of the optical switch matrix (10) to separate the optical label Head and optical packet payload, optical label transceiver processor (9) output and optical switch switching matrix (10) output are all connected output wavelength division multiplexer (11), the optical packet payload after the optical label head of new generation and exchange After multiplexing, it is connected to the optical label switching network through the optical fiber, and the optical label switching edge node (2) is connected to the computer terminal (1). 2. The optical label switching structure supporting blocking mode and multiplexing control according to claim 1, characterized in that, the computer terminal (1) includes delay time, address The electrical Ethernet packets with priority information converge into the optical label switching edge node (2), and the optical label switching edge node optical packet packaging and unpacking processor (5) according to the optical packet delay parameters, service priority and The terminal address information is packaged in the service aggregation queue; in the case of high-speed multimedia video flow, the computer terminal (1) sends a separate video flow control packet and pure video data packet to the optical label switching edge node (2). 3. The optical label switching structure supporting blocking mode and multiplexing control according to claim 2, characterized in that the control mechanism between the computer terminal (1) and the optical label switching edge node (2) is divided into blocking mode and multiplexing mode, blocking mode means that the pure video stream data packets and video control packets are sent to the same port of the optical label switching edge node (2), while the multiplexing mode is that the optical label switching edge node (2 ) receives the control packet at a separate port, the optical packet packaging and unpacking processor (5) identifies and processes the control information, and changes in real time the terminal address routing, optical packet priority and optical packet delay timing of the high-speed multimedia video stream packaged into optical packets Control information to complete the aggregation and transmission of high-speed video stream services at the terminal. 4. The optical label switching structure supporting blocking mode and multiplexing control according to claim 1, characterized in that the optical label switching core node (3) and the optical label switching core node (3) are interconnected via optical fibers even.