Scheme with external channels
Affiliated technical field
The invention belongs to the high-performance distributed switching router system in the communication network, be specifically related to the method that communicates by Ethernet between a kind of distributed switch router master control borad and the business board.
Background technology
The hardware based distributed route switching technology of general employing in the design of high performance distributed switch router, its route switching is handled the ASIC forwarding chip that mainly is distributed to each business board and is finished, switching backplane then adopts advanced CROSSBAR technology, thereby guarantees the surface speed forwarding of the high performance L2 of finishing of whole system~L7 layer.On function, high performance distributed switch router module can be divided into master control borad and business board, and master control borad is the control centre of router, and CPU and memory are just in master control borad.Master control borad is responsible for the management and the control of whole router, and IP routing protocol moves on master control borad.Master control borad directly receives the instruction from the network manager, and is issued to each interface board execution command, and each interface board is sent to master control borad to running status and statistics simultaneously, carries out necessary processing by master control borad.The static routing of network manager's configuration and the dynamic routing that generates by the operation Routing Protocol are managed by master control borad, and are issued to each business board, make each business board can carry out the forwarding work of packet independently.Business board mainly is to finish the function that packet is transmitted fast by the ASIC forwarding chip.At present, we claim the passage (adopting the CROSSBAR technology) of reciprocal exchange of business data between each business board ASIC forwarding chip to be in-band channel, business datum does not need just can realize exchanging by master control borad CPU or business board CPU, just can allow business datum transmit by hardware fully by setting to asic chip and CROSSBAR, and do not need the intervention of CPU, thereby accelerated the speed that business datum is transmitted, information between master control borad and the business board CPU, also can realize information exchange between master control borad CPU and the business board CPU by in-band channel, because master control borad CPU and interface board CPU can visit CROSSBAR and communicate by CROSSBAR, but adopt this mode, business datum is transmitted and master control borad CPU, information exchange between the business board CPU just has the place of one section coincidence on physical link, just all to finish through CROSSBAR, and the bandwidth of CROSSBAR is limited, if the business datum amount is bigger, just might cause the information dropout that exchanges between master control borad CPU and the business board CPU, and among these information some for example route sending-down information etc. be very important, if these information dropouts will cause the distributed switch router can't operate as normal.Therefore, adopting in-band channel to transmit all data is to be difficult to guarantee that wherein important data do not lose.
Summary of the invention
The present invention overcomes the unreliable of data information exchange between the master control borad of above-mentioned distributed multi-layer switches and the business board, a kind of Scheme with external channels that exchange message between master control borad and the business board and the passage that is used for the business datum forwarding are separated is provided, guarantee that when heavy traffic the exchange of information between the master control borad and business board can not be subjected to the impact of business datum, guarantee that important control information do not lose.
Technology contents of the present invention: a kind of Scheme with external channels comprises:
(1) adopt the Ethernet mode to be connected master control borad and business board by two layers of exchange chip;
(2) data message with master control borad and business board exchange is divided into control information and service related data;
(3) described service related data is packaged into the frame format of Ethernet, purpose MAC is appointed as the MAC Address of the purpose plate that will send, the service related data passage by Ethernet sends to the purpose plate;
(4) described control information is packaged into the frame format of control information, purpose MAC is appointed as the MAC Address of the purpose plate that will send, be issued to the transmit queue buffer memory, the control information passage by Ethernet sends to the purpose plate.
Described step (1) also comprises: the CPU of master control borad and business board is connected an ethernet controller respectively, and two layers of exchange chip sends to ethernet controller according to corresponding interface with the data message ethernet frame of master control borad and business board exchange.
Step (4) also comprises: the purpose plate will send acknowledgement frame to source plate after receiving control information, if source plate can not be received the affirmation of control information on time, will retransmit this control information.
Technique effect of the present invention: 1, out-band channel adopts the Ethernet mode to connect on physical layer, by two layers of exchange chip master control borad and business board are coupled together, distribute different MAC Address for every module board CPU, realize two layers of exchange of the information between master control borad CPU and the business board CPU, when can ensure that distributed multi-layer switches business datum high-performance between plate is transmitted, the reliability of control information exchange can not be subjected to the influence of business datum converting flow between master control borad and the business board.2, the data message with master control borad and business board exchange is subdivided into control information and service related data, and service related data is for example statistical informations of some unessential information, does not therefore need to guarantee reliability from software; And the very important for example route sending-down of control information information need guarantee reliable transmission from software.According to transmitting data characteristic from logic out-band channel being divided into and service related data passage and control information passage.The different demands of difference in functionality data message have been satisfied to Performance And Reliability, in the high efficiency that ensures the service related data exchange, satisfy the reliability requirement of control information data, promptly can guarantee the real-time of service related data and the reliability of control information simultaneously.3, for requiring reliability than higher control information, by communication between plates synchronization call mode, make the network manager when configuring distributed multi-layer switches, can know exactly whether configuration comes into force simultaneously on a plurality of module boards, thereby ensured the consistency of a plurality of module board information of distributed switch router, be convenient to the network manager and implement administration configuration, realized the synchronization call function of master control borad command down-transmitting business board.
Description of drawings
Fig. 1 is the out-band channel physical schematic;
Fig. 2 is the out-band channel logical schematic.
Embodiment
With reference to figure 1, Scheme with external channels of the present invention, comprise master control borad, business board and Ethernet switching chip, the CPU of master control borad and business board is connected an ethernet controller respectively, two layers of exchange chip couple together master control borad and business board by Ethernet, master control borad CPU is by its ethernet controller and two layers of exchange chip, control information is sent to the ethernet controller of business board according to corresponding interface, the ethernet controller of business board is analyzed ethernet frame, and control information is sent to business board CPU.
With reference to figure 2, the data message of master control borad and business board exchange is subdivided into control information and service related data; The information category of master control borad and business board exchange is many, mainly can be divided into two big classes, and a class is control information: the forwarding control information of calculating as network management configuration, Routing Protocol etc., and this category information requires reliability height, must guarantee the reliability of transmitting; One class is and service related data information, it mainly is the relevant data message of business that exchanges between master control borad and the business board, as add up numeration, abnormal frame etc., these class data do not require very high reliability, implement fairly simplely, as long as data message is encapsulated into the frame format of Ethernet, the MAC Address of purpose MAC being appointed as the purpose plate that will send just can send to the purpose plate by out-band channel.For requiring reliability than higher control information, simple Ethernet encapsulation is not enough, because Ethernet bandwidth itself also is limited, the amount of information of possible moment has surpassed the bandwidth upper limit of out-band channel when control information is a lot of, thereby causes information dropout; Simultaneously the CPU of distributed multi-layer switches master control borad and business board is handling different tasks usually, and the busy extent of same time may be different, causes sending and the speed accepted does not match, thereby causes losing of information.In order to solve this two problems, on the basis of simple two layers of exchange of Ethernet, realized proprietary control information frame encapsulation, use the mode of control information transmit queue buffer memory simultaneously.Issue with routing iinformation and to be example, specify the execution mode of control information of the present invention:
Master control borad CPU moves Routing Protocol (OSPF, RIP etc.), learns a new routing iinformation by Routing Protocol.Routing iinformation need be synchronized to each business board to guarantee the correctness of the distributed forwarding of business datum.
Routing iinformation is important control information, and master control borad CPU is packaged into the frame format of control information with routing iinformation, and issues module by control information this control information frame is put into transmit queue.
Master control borad control information transmit queue selects suitable opportunity that the routing iinformation of encapsulation is sent to the ethernet controller that links to each other with master control borad CPU.
Ethernet driver is encapsulated into ethernet frame format with the control information frame, and purpose MAC is set to the MAC Address of the business board that will send, and sends to two layers of Ethernet switching chip special-purpose and out-band channel by the Ethernet interface on the master control borad.Exchange chip finds the interface of business board correspondence according to target MAC (Media Access Control) address, and ethernet frame is sent to business board ethernet controller interface.
The business board ethernet controller is analyzed ethernet frame, and control information is sent to business board CPU, and business board CPU analysis and Control information is extracted the routing iinformation that issues and is set to forwarding chip, sends acknowledgement frame simultaneously to master control borad CPU.
Master control borad CPU receives acknowledgement frame, discharges this control information from transmit queue, if the overtime acknowledgement frame of not receiving then retransmits this control information, with the reliability that guarantees to send.
Network management configuration is all finished on master control borad at present, and the part network management configuration also will be issued to business board by out-band channel.The characteristics of network management configuration are that the network manager must know whether success just can be carried out next step configuration in configuration.Out-band channel has been supported this requirement, and the synchronization call passage is set, and is based upon on the control information channel base, can think that network management information is a kind of special control information, and the synchronization call passage is a special applications of control information passage.What it was different with general control information is, Pei Zhi the possibility of result can have influence on next step configured strategy of keeper each time, when general control information issues control information is put in the transmission buffer queue, just can generates control information once more and join the back that sends a last control information in the buffer queue; Because the control information that network management configuration information generates is put into the configuration next time that can not remove to accept webmaster behind the transmit queue at once, block to live the task of network management configuration this moment, do not allow that the network manager is configured, feed back the result of a last configuration up to business board, again the result is fed back to the keeper by network management interface, recover the operation of network management configuration task afterwards, the keeper just can carry out next bar and dispose.This realization has guaranteed that the network manager can not carry out irrational configuration because of the result of configuration before uncertain.When each administration configuration issues, master control borad CPU blocks the task of administration configuration, interface board receives that the information of administration configuration operates accordingly, after finishing, operation sends response message notifying operation result to master control borad, master control borad CPU receives that the operating result message wakes the network management configuration task up, with operating result output, the network manager can determine next step configuration according to the information of output simultaneously.