CN100496005C - Large-scale network control system - Google Patents
Large-scale network control system Download PDFInfo
- Publication number
- CN100496005C CN100496005C CNB2006101448684A CN200610144868A CN100496005C CN 100496005 C CN100496005 C CN 100496005C CN B2006101448684 A CNB2006101448684 A CN B2006101448684A CN 200610144868 A CN200610144868 A CN 200610144868A CN 100496005 C CN100496005 C CN 100496005C
- Authority
- CN
- China
- Prior art keywords
- control
- network
- data
- station
- domain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Data Exchanges In Wide-Area Networks (AREA)
Abstract
According to the control artwork or control range, the invention divides the process control network into several operation domains and control domains; all domains are interconnected in the process control layer through multicast exchanger to build a unified process control network; isolating each operation domain and control domain in order to make the real-time data transmission not influence the network loads of other domains; when other domains need to get the data of one domain, it can be implemented by simply configuring the operation domain.
Description
Technical field
The present invention relates to make up extensive automation real-time control network, relate in particular to a kind of large-scale network control system with the Industry Control Ethernet.
Background technology
Process data net in traditional industrial control system mostly adopts Ethernet, and generally adopts other bussing techniques for the higher process control network of reliability requirement.Now, ethernet technology is low by feat of cost, speed is fast, open and compatible advantage such as good more and more is applied to process control network.
And be applied in the process of industrial control system in ethernet technology, its inferior position also shows gradually, wherein topmost inferior position is exactly when the process control network size is big, it is big that network load becomes, the also corresponding increase of the load of each node, the real-time that transmits data is had a strong impact on, and causes the unreliable of transfer of data.
In the at present common system, process control network as shown in Figure 1, generally all be that active station and control station are connected in the consolidated network, mode by broadcasting or program request inquiry is carried out transfer of data, corresponding engineering teacher station and data server also all are connected in the above-mentioned consolidated network, the main problem of this network architecture is that network size is less, and too much Control Node access network can not be arranged, and has so just limited the control scale.
And for large-scale control system, present way is that The whole control system is broken the whole up into parts, be decomposed into a plurality of subsystems, each subsystem is separate, each subsystem is controlled respectively, and each subsystem is undertaken alternately by the process data net again, as shown in Figure 2, active station, engineer station, server and by described active station directly the control station of monitoring be connected and constitute a subsystem in the same process control network, undertaken alternately by the process data net again between a plurality of subsystems.Such network architecture can be realized large-scale control, needs to pass through earlier the server of subsystem separately but problem is the communication between each subsystem controls station, connects by described process data net again.Such one is the ageing very big influence that is subjected to, the 2nd, and data reliability also is affected.Another problem is that the active station of each subsystem can only control the control station in the subsystem of place, and need be by the process data net again by the server forwards of this control station place subsystem to the monitoring at other subsystem controls stations.Both influenced the ageing reliability that also influences so equally.Though this network architecture will be connected into network than multinode and control, because each several part is separate, be exactly the simple expansion of first kind of scheme in fact, the extensive control of the real meaning that is unrealized.
For extensive control system, also has a kind of connected mode that adopts gateway at present, as shown in Figure 3, equally Control Network is divided into several subsystems, active station, engineer station, server and by described active station directly the control station of monitoring be connected and constitute a subsystem in the same process control network, each subsystem adopts different IP sections, and the communication between each subsystem adopts gateway to realize.This network architecture subject matter is that the data traffic between each subsystem is very limited, and can not carry out the transmission of mass data owing to be subjected to the influence of gateway, and is very big to the ageing influence of system's control.
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of large-scale network control system that can solve problems such as extensive Control Network real-time, reliability, network load, control authority management.
For solving the problems of the technologies described above, the present invention adopts following technical scheme: a kind of large-scale network control system comprises:
Multicast device: be used to realize the interconnection between each process control network, can realize forwarding and filtration, thereby realize not the mutual of multi-case data between same area according to the multicast management agreement to multi-case data;
Process control network: be used to transmit all control datas and real time data;
Control station: be used for directly and on-the-spot I/O processing unit of coming into contacts with, finish the real-time monitoring and control of whole industrial process;
Active station: be used to monitor described control station, the man-machine system environment of complete process monitoring management task;
At least one described control station is divided in same group by a process control network, constitutes a control domain with the process control network that links to each other, and at least one active station links to each other with described process control network and constitutes an operation domain;
Active station in control station in a plurality of control domains and a plurality of operation domains process control network by separately respectively links to each other with described multicast device.
Also can comprise the process data net, be used for transfer management type data, each operation domain can link to each other with distant-end node by described process data net.
Described distant-end node can comprise the server that is used for the backup procedure data and be used for showing in real time and reporting the application station of process data.
Described operation domain also can comprise all-in-service station, and described all-in-service station is used to realize system maintenance, and interconnected by process control network and described active station.
Described operation domain also can comprise server, and described server is used to deposit the management type data that comprise historical record, failure logging, operation note, and interconnected by described process data net and described active station.
Each control domain and operation domain can be divided in the same subnet, distinguish with different IP sections.
Each internodal connection and data send, receive the mode that can adopt double-network redundant in the described system.
Control Node can adopt two control station redundant configuration in the described system, and two control station IP addresses are adjacent.
Compared with prior art, the present invention has following advantage: according to the control technology in the control system or according to control range, be divided into operation domain and control domain, each territory interconnects by the multicast switch at the process control stratum reticulare, constitute unified process control network, each operation domain and control domain are kept apart, the real-time Data Transmission of each control domain does not influence the network load in other territories, when other operation domains need these control domain data, can realize by operation domain is carried out easy configuration again.So both flexible, limited the work authority of operation domain again, the overall network load also greatly reduces.And in same control domain, because control station do not receive real-time multi-case data, so control station is not subjected to the influence of other real-time multi-case datas in the control domain of place, greatly reduces the node load of control station.
Description of drawings
Fig. 1 is existing general industry control system structure chart;
Fig. 2 is a kind of existing large-scale industry control system structure chart;
Fig. 3 is another kind of existing large-scale industry control system structure chart;
Fig. 4 is large-scale network control system structure chart among the present invention.
Embodiment
As shown in Figure 4, structure chart for large-scale network control system described in the present invention, according to control technology or according to control range, the people is for being divided into three operation domains and three control domains, be respectively 1#, 2#, 3# operation domain, 1#, 2#, 3# control domain, each territory is relatively independent, each node connects by general switch in each territory, realizes data interaction in the territory by network in the territory.Interconnect by the multicast switch at the process control stratum reticulare between each territory, constitute unified process control network, described process control network is used to transmit all control datas and real time data.
Described operation domain be will monitoring scope and authority and the close active station of technology be divided in same operation domain, and can monitor the logic branch territory of a plurality of control domains simultaneously.Comprise at least one active station in the described operation domain, described active station is the man-machine interactive system that can be made up of Industrial PC Computer, CRT, keyboard, mouse, printer etc., is the environment of operating personnel's complete process monitoring management task.Can also be equipped with all-in-service station, server according to needs separately, described all-in-service station also can be described as the engineer station for specialized engineering technical staff design, in corresponding system maintenance instrument is housed, with work system is carried out in good time maintenance and renewal.Described server is used for every historical record, failure logging, operation note of storage system running etc.Each node in the described operation domain comprises that described active station and engineer station and server all are connected one by general switch or router and independently realize in the process control network interconnected.
Described control domain is according to field control technology a plurality of control stations to be divided in same group physics branch territory, also is connected one by general switch or router between each control station and independently realizes in the process control network interconnected.Each control station is the control system core component, it is direct and on-the-spot I/O processing unit of coming into contacts with in the system, it can be the input and output acquisition module of direct analog or digital, it also can be gateway device by various different agreements, with other isomery equipment realize interconnected, thereby finish the real-time monitoring and control of whole industrial process.
Described multicast switch respectively with above-mentioned each control domain and operation domain in each independently process control network interconnection, can realize transmitting and filtering according to multicast management agreement (IGMP), thereby realize not the mutual of multi-case data between same area multi-case data.Described multicast switch also can adopt other network switching equipment that can support the multicast management agreement to realize, as router etc.Because the network equipment of nearly all support multicast function all can support IGMP to add and the igmp querying corresponding function simultaneously, each engineer station, active station and control station all should possess two cover IGMP transmit mechanisms, the one, regularly send IGMP and add packet to described multicast switching equipment, the 2nd, respond the IGMP multicast data query bag that the multicast switching equipment is sent, general IGMP multicast inquiry can be set at per 60 seconds once, is used for periodic refreshing configuration member tabulation; And the active by the multicast group membership adds or withdraws from, and also can in time refresh described configuration member's tabulation, thereby guarantees the reliability of multicast transmission when adjusting multicast group configuration member at any time flexibly.
Each operation domain interconnects by the process data net on the upper strata, described process data net is used for the configuration server, use the station, active station in the long station of value and other distant-end nodes etc. and on-the-spot each operation domain, data server links to each other, transmission non-controlling data, these data are not participated in control directly, but be used for the management on backstage, be the management type data, as configuration data, historical record, operation note, the copies data of failure logging etc. is transferred to by described process data net and realizes the configuration copy behind the far-end, the backup of fault alarm record copies, real time data reports demonstration etc.Management type data between described each far-end Control Node and the described operation domain and the data interaction between each operation domain, no longer transmit by process control network, but finish by described process data net, make control type data and management type data separating, only transmit the control type data in the process control network, and transfer management type data only in the process data net, like this management type data in the process control network territory or between the territory data volume in the data channel reduce relatively, both reduce network load, reduced failure rate, reduced the complexity of process control network data again.
Below in conjunction with Fig. 4 the control procedure of large-scale network control system among the present invention is described in detail.
At first, by the switch that the multicast function is arranged being supported the configuration of multicast transmission function and IGMP protocol function, can realize the multicast management function of switch; With the 1# operation domain to 1#, the 2# control domain be controlled to be example, 1# operation domain engineer station and active station configuration configuration monitoring 1#, 2# control domain data, drive transmission two bags by network interface card and add described 1#, the IGMP packet of the real-time multi-case data of 2# control domain place multicast group, be specially, in the active station and engineer station in the 1# operation domain, judge according to configuration which multicast group data PC network interface card needs receive, calling the bottom network interface card drives, receive corresponding multi-case data, and when starting, receiving process sends an IGMP management packets, add the multicast group, same, as described 1#, when powering on, the control station in the 2# control domain also sends the IGMP packet to described multicast switch, as long as the multicast switch is received IGMP data that a node is sent and the multi-case data of correspondence will be forwarded to the port at this node place, and only need to respond the multicast data query that the multicast switch sends subsequently, the multicast routing table is refreshed in real time.Wherein, described IGMP packet content comprises the multicast address that version, IGMP type (inquiry, response, active adding etc.), needs add.
The multicast switch is according to the configuration of above-mentioned IGMP data, notice multicast switch carries out the data multicast and transmits, 1#, 2# control domain multicast real time data with 1# operation domain needs, be forwarded to the 1# operation domain place network port by described multicast switch, receive by active station in the 1# operation domain or engineer station again, thereby realized of the monitoring of 1# operation domain 1#, 2# control domain data.
In addition, consider that on-the-spot multicast switch may be changed temporarily, send out an IGMP packet if just power on, the multicast routing table of changing the back switch at switch can not in time be refreshed, therefore can adopt the mode of timed sending, promptly described each network node regularly sends the IGMP packet to described multicast switch, refreshes described multicast routing table, but the described timed sending cycle does not have strict requirement, generally can be 3～5s; In addition, consider in the network segment that is difficult to judge under the multicast switch port what nodes are arranged, therefore can adopt all nodes all to respond the mode of inquiry.
Like this, each operation domain can independently be controlled the monitoring of control domain, not influenced by other territory, the switch of multicast simultaneously is according to the above-mentioned preparation of described multicast management data, the multi-case data that active station in the 1# operation domain is implemented monitoring to described 1#, 2# control domain is forwarded in each control station of described 1#, 2# control domain, by each control station the data of returning are forwarded in the 1# operation domain by described multicast switch again, finish monitor procedure one time.By control to operation domain multi-case data and IGMP packet, the data of one or more control domains of while necessary for monitoring, realized that operation domain is combined into the function of line data monitoring to different control domains, data such as mutual are undertaken by the mode of multicast between main real time data and station in process of data communication, can guarantee the data that each territory receives only oneself to be needed, when having guaranteed that real time data is effectively transmitted, control to a plurality of territories needn't send to each node by the mode of broadcasting, but therefore purposive direct transmission has reduced in the network, internetwork load and node load.
When other territories need this numeric field data, can realize by operation domain is carried out easy configuration again, other operation domain monitoring principles are identical, for example the 2# operation domain need be monitored 2#, 3# control domain data, send the IGMP packet that 2 bags add described 2#, 3# control domain multicast address, its place port of notice multicast switch adds 2#, 3# control domain place multicast group, and the multicast switch is transmitted to the 2# operation domain with the multicast real time data of 2#, 3# control domain.In like manner, if the 3# operation domain sends 3 bag IGMP packets to 1#, 2#, 3# control domain respectively, notice multicast switch receives the real-time multi-case data of whole three control domains, described multicast switch will all be transmitted to the 3# operation domain with the all-multicast real time data of 1#, 2#, 3# control domain, thereby realizes the monitoring of 3# operation domain to each control station data in the whole network.
By also can limit the operating right of each territory active station to the multicast setting in each territory and management, for example described 1# operation domain disposes described 1#, 2# control domain when configuration, make the data of 1# operation domain be merely able to be received by 1#, 2# control domain, and can other control station not had an effect the management of therefore clear and definite each operation domain monitoring range and control authority.Introduce the isolation of multicasting technology and multicast switch, realized effective utilization of network.And because each territory is relatively independent, certain domain node or network go wrong on network, can not feed through to whole network, have realized effective isolation of network failure.
Further, when needs carry out communication between the control station, all control stations send same IGMP multicast management data to described multicast switch, join in the same multicast group, when control station will carry out between control station communication, for example, the data of gathering in a certain control station in the 1# control domain need be shared with other control stations, then the mode by multicast from the 1# control domain to 1#, 2#, the 3# control domain sends communication data between control station, can guarantee that all control stations that link to each other with the multicast switch in the system can receive this communication data, each control station carries out inter-process more respectively, and can guarantee that other network nodes except control station can not receive these data.
System of the present invention is as follows based on further specifying of osi model layering:
Physical layer: by the connection of general network equipment in the territory and the connection of the network equipment between the territory of supporting multicast, for hardware platform has been built in large scale unified networks control.Described network is based on the network standard of Ethernet and IEEE802.3/802.3u encapsulation, mainly adopts the 100Base-TX/FX full-duplex mode, and the network equipment all adopts switching network equipment, comprises router and switch etc.
Data link layer: each node of network adopts Ethernet interface chip or network interface card, because the integrated Ethernet interface function of meeting among some CPU, though in communication, can realize equally like this, but be not suitable for the such network of industrial process control Ethernet, and in the Industrial Ethernet, especially at control station, then require Ethernet interface reliability height, antijamming capability height, here then should adopt on hardware designs, insert the Ethernet interface chip of CPU by the mode of isolating, its reliability and antijamming capability can improve a lot like this.Realize bottom layer driving, finish the Ethernet data bag and send, receive, and the Ethernet interface chip is carried out Interrupt Process, troubleshooting, initialization process or the like work.No matter be engineer station, active station, control station or switch, all need maintaining routing list, realize the maintenance and the renewal of each node route list on the network by the ARP packet.For guaranteeing correctly and in time refreshing of routing table, engineer station, active station and control station possess two cover ARP transmit mechanisms, the one, by each all in process control network terminals, all terminal broadcast transmission ARP packets in whole process control network, for example engineer station, active station and control station fixed time broadcast send the ARP packet of inquiry self address, be used to upgrade each node route list and judged whether duplicate node, the 2nd, engineer station, active station and control station are responded the ARP data query bag of above-mentioned broadcasting or program request.Wherein, cyclic redundancy check (CRC) (CRC check) is adopted in the transmission of data, for example transmitting terminal is when sending packet, network chip can automatically add the CRC check of 4 bytes behind packet, because the transmission of ARP all is (promptly one to one or one arrive many) end to end, switch is only transmitted the packet of reception, and do not process, after packet arrives receiving terminal, by receiving terminal described CRC check is judged again, thereby solved the check problem that causes wrong bag on the ethernet communication circuit because of interference.
Network layer: adopt IP, ICMP, IGMP agreement.In network, different territories is divided in each territory respectively in the same subnet by the network node setting, but need be divided into different IP sections.Network Transmission realizes the mode that broadcasting, multicast, the program request of IP address are used with by the difference setting of described multicast switch.Because in the assurance that physical layer network connects, the transmission of the order program data of node-to-node can be guaranteed on the network; And because each node is in same subnet, the broadcast data that network node sends can be received by all nodes.
Transport layer: owing to adopted the mode of IP address multicast, transport layer adopts udp protocol to realize transfer of data.The advantage of udp protocol is that transmission speed is fast, ageing good, is fit to the transmission of real time data.
For guaranteeing the reliability of Network Transmission, online each node of described process control adopts the mode of double-network redundant to connect, and online each switch of respective process control also adopts the configuration of double-network redundant.When data send, the mode that node adopts the two nets of bag data to send simultaneously; During Data Receiving, node receives the data of two networks, gets wherein a bag and handles.The connection of two nets and transmission receive mode have improved reliability of data transmission greatly.When problem such as broken string, network blockage occurring when network, another network still can normal transmission, has guaranteed the unobstructed of transfer of data.
For the online key node of process control, as control station etc., adopt the mode of redundant configuration, promptly a Control Node adopts two control station redundant configuration, two redundant control stations are regarded two network terminals as, two control station IP addresses adjacent (not doing sign among the figure).On the IGMP multicast management, two redundant control stations all timed sending IGMP add packet, also all respond the igmp querying bag, and during operate as normal, one of them control station is an operating state, controls and receive transmission normally; Another control station is in stand-by state, does not participate in control, does not also send real time data, and just the data with work station in time copy the back-up of coming.When former work control station went wrong, such as network problem, former standby control station just became the work control station, and former work control station becomes standby control station.So when one of them control station goes wrong, can in time switch to another standby control station, guaranteed process control reliable and network real-time Data Transmission reliably.
For program request inquiry class data, each territory is owing to connect by the multicast switch, and whole process control network network node IP is in same subnet, and the order program data between the territory needs only the configuration according to IGMP multicast management data, transmit by the multicast switch again, need not gateway processes can realize.Communication does not need by the process data net again between control station, and effective and fail safe is strengthened greatly.
Simultaneously, in the establishment that the node-to-node network connects, need confirm whether destination node exists by the PING bag of ICMP agreement, when originating end runs into data can't access destination, when switch can't be transmitted situation such as packet by current transmission rate, can carry out the PING inquiry by automatic transmission ICMP message, send the icmp echo request message and record icmp echo by destination again and reply message, notify the other side's oneself existence, come to provide reference frame the fault in system or each territory by these message.
In addition, because the characteristic of Ethernet itself when node sends data, unsuccessful problem may occur sending, network load is heavy more, and this problem is obvious more, therefore, can introduce the conflict retransmission mechanism in said system, can avoid this problem significantly.When needs send data, network chip detect network whether have data send, Ethernet chip sends whether buffering area has living space, whether normal network connect many situations such as, judges when not possessing the transmission condition, then withdraw from etc. and to send these data next time again.Continuous several times sends these data when all failing, and thinks that these data lost efficacy, abandons, and then sends next data.This machine-processed advantage is the data-bag lost that can avoid network conflict to cause, also can not guarantee to send and can be wrapped the data obstruction by certain, causes other follow-up datas normally to send.
According to the needs of difference control occasion, by to sending different multicast management data for described multicast switch, can adjust multicast group configuration member at any time flexibly, thereby realize different multicast group combinations and flexible control different control domains.
Above-described embodiment of the present invention does not constitute the qualification to protection range of the present invention.Any modification of being done within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within the claim protection range of the present invention.
Claims (8)
1, a kind of large-scale network control system is characterized in that: comprising:
Multicast device: be used to realize the interconnection between each process control network, can realize forwarding and filtration, thereby realize not the mutual of multi-case data between same area according to the multicast management agreement to multi-case data;
Process control network: be used to transmit all control datas and real time data;
Control station: be used for directly and on-the-spot I/O processing unit of coming into contacts with, finish the real-time monitoring and control of whole industrial process;
Active station: be used to monitor described control station, the man-machine system environment of complete process monitoring management task;
At least one described control station is divided in same group by a process control network, constitutes a control domain with the process control network that links to each other, and at least one active station links to each other with described process control network and constitutes an operation domain;
Active station in control station in a plurality of control domains and a plurality of operation domains process control network by separately respectively links to each other with described multicast device.
2, large-scale network control system as claimed in claim 1 is characterized in that: also comprise the process data net, be used for transfer management type data, each operation domain can link to each other with distant-end node by described process data net.
3, large-scale network control system as claimed in claim 2 is characterized in that: described distant-end node comprises the server that is used for the backup procedure data and is used for showing in real time and reporting the application station of process data.
4, large-scale network control system as claimed in claim 1 or 2 is characterized in that: described operation domain also comprises all-in-service station, and described all-in-service station is used to realize system maintenance, and interconnected by process control network and described active station.
5, large-scale network control system as claimed in claim 2, it is characterized in that: described operation domain also comprises server, described server is used to deposit the management type data that comprise historical record, failure logging, operation note, and interconnected by described process data net and described active station.
6, large-scale network control system as claimed in claim 1 or 2 is characterized in that: each control domain and operation domain are divided in the same subnet, distinguish with different IP sections.
7, large-scale network control system as claimed in claim 1 or 2 is characterized in that: each internodal connection and data send, receive the mode that adopts double-network redundant in the described system.
8, large-scale network control system as claimed in claim 1 or 2 is characterized in that: Control Node adopts two control station redundant configuration in the described system, and two control station IP addresses are adjacent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006101448684A CN100496005C (en) | 2006-11-23 | 2006-11-23 | Large-scale network control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006101448684A CN100496005C (en) | 2006-11-23 | 2006-11-23 | Large-scale network control system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1960309A CN1960309A (en) | 2007-05-09 |
| CN100496005C true CN100496005C (en) | 2009-06-03 |
Family
ID=38071810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006101448684A Expired - Fee Related CN100496005C (en) | 2006-11-23 | 2006-11-23 | Large-scale network control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100496005C (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101515175B (en) * | 2009-04-16 | 2011-07-20 | 浙江浙大中控信息技术有限公司 | Data transmitting method, data processing method and industrial control system |
| CN103458068A (en) * | 2013-05-09 | 2013-12-18 | 深圳信息职业技术学院 | Method and system for detecting and controlling network control system |
| DE102017010473A1 (en) * | 2017-11-10 | 2019-05-16 | Oerlikon Textile Gmbh & Co. Kg | Machinery for the production or treatment of synthetic threads |
-
2006
- 2006-11-23 CN CNB2006101448684A patent/CN100496005C/en not_active Expired - Fee Related
Non-Patent Citations (7)
| Title |
|---|
| . . |
| 公伯峡水电站计算机监控系统. 何建辉，王龙.西北水电，第1期. 2005 |
| 公伯峡水电站计算机监控系统. 何建辉，王龙.西北水电，第1期. 2005 * |
| 基于交换式技术的工业以太网实时性问题的研究. 黄安贻，叶菁.机电工程技术，第34卷第4期. 2005 |
| 基于交换式技术的工业以太网实时性问题的研究. 黄安贻，叶菁.机电工程技术，第34卷第4期. 2005 * |
| 基于工业以太网的自控系统应用. 邱伟民.有色冶金设计与研究，第26卷第1期. 2005 |
| 基于工业以太网的自控系统应用. 邱伟民.有色冶金设计与研究，第26卷第1期. 2005 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1960309A (en) | 2007-05-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100589433C (en) | Method and system for providing clock synchronization by packet network | |
| CN101483558B (en) | Method, system and apparatus for packet switching network access by network appliance | |
| CN1980230B (en) | Method for managing VRRP group | |
| US11025537B2 (en) | Multiple RSTP domain separation | |
| CN101252427B (en) | Switch method of main-standby routers connecting with main-standby interfaces of medium gateways | |
| EP2533475B1 (en) | Method and system for host route reachability in packet transport network access ring | |
| CN101652963B (en) | Method for reconfiguring a communications network | |
| CN102255757B (en) | Link switching method and device | |
| US20050050379A1 (en) | Method and apparatus for network fault correction via adaptive fault router | |
| CN101141381B (en) | Network node and method of reducing medium access control address learning in looped network thereof | |
| CN102394787A (en) | Dual-link redundancy control method based on EPA switch | |
| TW200421777A (en) | High availability Ethernet backplane architecture | |
| CN100544286C (en) | A kind of method and system that realize backup link of virtual private LAN service network | |
| CN102119510A (en) | A multi-path network | |
| US9019816B2 (en) | Communication system, communication method, and communication apparatus | |
| CN103139060A (en) | High-fault-tolerance controller area network (CAN) bus digital gateway based on double digital signal processors (DSPs) | |
| CN103166800B (en) | Message transmission method for dual-network redundant message bus in cross failure | |
| CN102984057A (en) | Multi-service integration dual-redundancy network system | |
| CN110838962B (en) | Marine network system and marine system | |
| CN102055658B (en) | Method and equipment for realizing failure protection in rapid ring protection protocol single-ring networking | |
| CN108337161A (en) | Method for smoothly switching M L AG interface fault three-layer data flow | |
| CN110611590A (en) | Method and system for internet of things gateway communication backup | |
| CN104579981B (en) | A kind of multicast data packet forwarding method and apparatus | |
| CN100496005C (en) | Large-scale network control system | |
| CN101136838B (en) | Bridge mode elastic grouping ring transannular bridge equipment redundancy protecting method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090603 Termination date: 20201123 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |