CN1697337A - Rearrangement method in communication system - Google Patents

Abstract

The invention relates to a communication method, and discloses a switching method in a communication system, which makes the switching operation of service channels before and after switching simple, reliable, fast and efficient, and meets the switching requirements of telecom-level equipment. This switching method in the communication system uses the control board to centrally control the switching operation of the single board on the bus in the communication system based on the shared memory communication mode, and the single board in the frame realizes transparent switching through the logic slot and physical slot mapping mechanism During the switchover, only the logical slot and physical slot mapping table need to be updated, and the sending and receiving channel mapping information and the control command word address need to be updated under the inter-chassis communication, including control board switching and equipment board switching. way of operation.

Description

Switching method in communication system

technical field

The invention relates to a communication method, in particular to a single board switching method in a communication system based on a shared memory communication mode.

Background technique

Telecommunications networks are required to provide reliable and uninterrupted services to their users, especially in some important business applications, such as electronic money, order processing, customer service, inventory management, e-mail and Internet access, etc., business survivability becomes more important than ever, with availability requirements of 99.999% and beyond. Therefore, the network survivability has become an important factor affecting network design and construction, and the equipment used in the telecommunication network also needs to have high reliability accordingly.

Redundant backup and master-standby switching technology is a commonly used solution. Redundant backup and active-standby switching technologies have various backup modes, such as 1+1, 1:1, 1:N, etc. 1+1 backup is a simple protection method. The main and backup units in the system form a logical business function unit, that is, the protected equipment unit has a backup unit, and the main module is responsible for real-time processing of services. The data of the active unit is consistent, and a switchover is initiated when a failure of the original active unit is detected, and services on the original active unit are taken over. In the 1:1 backup, which is different from the 1+1 backup, the backup unit only starts to work after a failure occurs. The 1:N backup means that multiple equipment units share a backup unit. When any active unit fails, the backup unit will take over its work.

Usually, a complex telecommunication device includes multiple processing units working together, and communication between the units is required; and in the entire communication network, communication between different node devices is also required. In order to ensure the self-healing ability of equipment under network failure conditions, ensure data integrity and maintain service quality, the switching must be completed within the specified time limit, and the business can be restored as soon as possible, so as to minimize the impact on the communication system. It can be seen that the performance of the protection switching mechanism has a significant impact on the reliability of the system and even the survivability of the entire network.

Switching methods currently used in communication systems mainly include switching methods based on circuit switching and Internet Protocol (Internet Protocol, referred to as "IP") communication.

Fig. 1(a) shows a switching device in a traditional circuit switching system. The circuit switch is realized through the "switching network". The switching network unit includes two units of the active and standby switching planes to achieve the effect of redundant backup. Each service processing unit is physically connected to the active and standby switching units, and data can be sent and received from both switching planes, but only the data processing on the active plane is used during normal operation. When the switchover of the switching network unit occurs, it will notify all instructing service modules to switch to the new switching plane. In order to ensure that the switching operation is completed within the specified time limit, the switching of the switching network unit must be realized by hardware. In addition, each business processing unit also includes an active and standby business processing unit for protecting respective business communications. For the active and standby service processing units, the switching network adopts the working mode of "one send and two receive", that is, the service data is simultaneously switched to the input/output ports of the active and standby service processing units. The operation mode of port sending and receiving is determined by arbitration or heartbeat handshake between the active and standby service modules. During normal operation, only the active unit will process business and send data, and the output port of the standby module is disconnected or in a high-impedance state; when switching occurs, the active and standby units decide to disconnect or operate the input/output port according to the arbitration result.

Fig. 1(b) shows a switching device in a traditional IP network. Each device or network node in the IP network is assigned an independent IP address, and the switching operation is realized by switching the IP address. For example, there is a dual-machine backup network server on the network. When one server that is providing services suddenly loses power or goes down abnormally, the other backup server will immediately switch to its IP address to take over the service.

It can be seen that for the traditional switching technology based on circuit switching, since the active/standby arbitration and switching notification need to be directly implemented by hardware, it must be connected or wired on the backplane, which has poor versatility and scalability and high cost. For the switching technology based on IP-based dual-system backup, its switching performance is directly limited by the limitations of IP technology, such as uncertain transmission delay and unguaranteed transmission bandwidth, which makes it far from being able to meet real-time business and high-service requirements in telecom networks. quality needs.

In practical application, the above solutions have the following problems: the switching technology based on circuit switching must be implemented by hardware, which has poor versatility and scalability and high cost; the switching technology based on IP cannot be applied to real-time, high-quality telecommunication services.

The main reason for this situation is that the switching device implemented by hardware must be designed for specific system circuits, which is not easy to upgrade and test, and the cost is high; the switching technology of IP address switching is directly limited by IP technology, and IP technology has transmission time Uncertain delay, transmission bandwidth is not guaranteed and transmission quality is not high.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a switching method in a communication system, which makes the switching operation of service channels before and after switching simple, reliable, fast and efficient, and meets the switching requirements of telecom-grade equipment.

To achieve the above object, the present invention provides a switching method in a communication system, the system includes a plurality of single boards, including at least one control single board, which is used to centrally control all the single boards through the bus to perform shared memory communication ; The single board also includes a logical slot and a physical slot mapping table, which is used to indicate the mapping relationship between the logical slots and the physical slots of all single boards, and the single board needs to be switched. The following steps are included:

The control single board of A modifies the logical slots and the physical slot mapping tables on all the single boards, and maps the logical slot number of the original active single board to the physical slot number of the original standby single board;

B. The control single board modifies its own logic slot numbers stored on the original active and standby single boards.

Wherein, said step A further includes the following sub-steps:

The control single board described in A1 modifies the logical slot and physical slot mapping table on this board, maps the logical slot number of the original primary board to the physical slot number of the original standby board, and maps the original The logical slot number of the board is mapped to the physical slot number of the original main board;

The control single board described in A2 synchronizes the contents of the updated logical slot and physical slot mapping table of this board to the logical slot and physical slot mapping tables of all other single boards.

The communication system is based on the Compact Peripheral Interconnect bus platform.

The present invention also provides a switching method in a communication system, the system includes at least two frames communicating with each other, each frame includes a plurality of single boards, including at least one control single board, which is used to centrally control the All the single boards in the frame perform shared memory communication; the control single board also includes a channel information table, which is used to save the mapping relationship between the logical slot numbers of all the single boards in the frame and the base address of the sending and receiving data storage area, and the control When a board needs to be switched, the following steps are involved:

D performs bus control switching, the original main control single board releases the bus control right, and the original standby control single board takes over the bus control right;

E updates the channel information table stored on the original active control single board and the original standby control single board, and maps the logical slot number of the original active control single board to the sending and receiving data of the original standby control single board storage area base address;

F prohibits the original active control board from allocating receiving channels to the device board.

Among them, when the boards other than the control board in the system are switched, the following steps are included:

G updates the channel information table stored on the control single board, and maps the logical slot number of the original active single board to the base address of the sending and receiving data storage area of the original standby single board;

H updates the control command word address information used to realize the shared memory communication between the bottom drive modules on the original active single board and the original standby single board;

1. The control single board modifies the self-logic slot numbers stored on the original active single board and the original standby single board.

Before the switchover, check whether the active and standby boards involved in the switchover are in use, and if so, start the switchover.

The communication system is based on the Compact Peripheral Interconnect bus platform.

The blocks can communicate through asynchronous transfer mode.

Through comparison, it can be found that the difference between the technical solution of the present invention and the prior art is that in a communication system based on a shared memory communication mode, the control single board is used to centrally control the switching operation of the single board on the bus, and the single board in the frame passes through the logical slot and physical slot mapping mechanism to realize transparent switching. During switching, it is only necessary to update the logical slot and physical slot mapping table. Under inter-chassis communication, it is also necessary to update the sending and receiving channel mapping information and the control command word address for switching, including There are two operation modes: control board switching and device board switching.

The difference in this technical solution has brought obvious beneficial effects, that is, because the shared memory communication method provides convenient bus operation, the logical slot and physical slot mapping mechanism provides a simple switching operation mode, and the centralized bus The control ensures the reliability and real-time performance of the switching, and the channel mapping mechanism realizes the switching under the condition of inter-frame communication. Improved system scalability and network survivability.

Description of drawings

FIG. 1 is a schematic diagram of the principle of an existing switching technology;

Figure 2 is a schematic diagram of the structure of the PSM frame, the shared memory communication mechanism and the inter-frame communication mechanism;

FIG. 3 is a flow chart of a switching method implemented by modifying a logical slot and a physical slot mapping table according to an embodiment of the present invention;

Fig. 4 is a flowchart of a switching method implemented by modifying a channel information table under inter-frame communication according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

The invention is based on the shared memory communication technology, completes the switching operation of the equipment unit through the modification of the address mapping, and can meet the requirements of real-time performance and transparency.

In shared memory communication, multiple equipment units realize memory sharing through bus access, each single board on the same bus realizes data communication through reading and writing of shared memory area, and communication between different buses can be realized through other interface technologies. In the present invention, there is a mapping relationship between the physical position and the logical position of each single board on the bus, and the transparent switching of the equipment unit is realized through the modification of the mapping relationship, which has good scalability and real-time performance.

In one embodiment of the present invention, a PSM frame based on a Compact Peripheral Component Interconnect (CPCI) bus platform is used to realize switching of individual boards on the bus, that is, switching of equipment units.

CPCI is a high-performance industrial bus based on the Peripheral Component Interconnect ("PCI") standard, and at the same time inherits the mechanical characteristics of European boards to achieve a reliable structure. There are 16 slots in the PSM frame, and boards can be inserted in the front and rear. There are four main types of boards, which are called URCU, UACU, UGPU, UFIU, and the general-purpose PCI Mezzanine Card ("PMC"). Among them, the URCU board is the control single board in the PSM frame, responsible for the management function of the PSM frame, and adopts 1+1 backup; the UACU board is the auxiliary control single board in the PSM frame, which assists the URCU board to complete the control function and is mainly used to implement the PSM The interconnection between physically different segments of the bus in the frame is used in pairs with the URCU board; the UGPU board is the business processing unit in the PSM frame and supports various business types. A maximum of 12 UGPU boards can be configured in a PSM frame. It can be configured as 1+1 backup or 1+N backup according to the business type. PMC is a small subboard in the CPCI system, which can be attached to the URCU board or UGPU board according to the configuration needs. Both URCU and UGPU provide a common PMC interface. PMC is generally used to complete specific functions or enhance processing functions; UFIU The board is used to realize the connection between the frames, and it is specially used for the optical interface board of the asynchronous transfer mode (Asynchronous Transfer Mode, referred to as "ATM") optical network.

Figure 2(a) shows the structure, components and inter-frame communication connections of the PSM frame.

In the PSM frame, the communication between the boards is mainly based on the PCI bus technology, the communication between the URCU board and each UGPU board is based on the CPCI backplane bus, and the communication between the URCU board or UGPU board and the PMC daughter board is based on the internal load board PCI bus. The electrical connection and address conversion functions are realized by Application Specific Integrated Circuits (ASIC) chips such as PCI bridges among the boards, that is, as long as the bridges are correctly configured, all boards in the CPCI platform can The memory space of each other can be accessed each other, and this communication method realized by accessing shared memory is shared memory communication. According to the PCI bus specification, the PCI bus can be cascaded through the PCI bridge. However, due to the limitation of electrical characteristics, only 8 PCI devices can be connected to each section of the PCI bus. Therefore, the backplane of the PSM frame with 16 slots is actually Composed of two sections of CPCI bus. The bridge between the two CPCI buses is completed through the UACU board to realize cross-bus access and communication between buses. But for each segment of CPCI bus, only one PCI master device can complete the bus arbitration at the same time, so the URCU board has only one master board to control the two segments of CPCI bus in the active and standby mode, and the standby URCU board is connected with the two segments of CPCI When the bus is disconnected and the URCU board is switched, the standby URCU board seizes the bus control right, the active URCU board releases the bus control right, and the corresponding UACU board is also switched together with the URCU board.

The shared memory communication of the PSM box is mainly completed by the UFIU bottom driver, the CPCI bottom driver and the PMC subboard bottom driver module. The PSM frame is implemented through the ATM server + client mode, and is carried by the ATM optical transmission network. The optical interface of the UFIU is connected to the ATM optical transmission network, and the underlying driver module of the UFIU completes the communication between the PSM frames. The CPCI underlying driver module completes the communication between the URCU board and each UGPU board in the PSM frame. The communication module at the bottom of each PMC subboard completes the communication between its load board and the PMC subboard. It can be seen that when the switching of the URCU or UGPU board occurs, the communication modules related to the switching only involve the UFIU bottom-layer driver module responsible for inter-frame communication or the CPCI bottom-layer driver module responsible for intra-frame communication.

Figure 2(b) shows the memory sharing mechanism among the individual boards on the CPCI bus. The working principle of the communication module at the bottom of CPCI is the memory sharing among the boards. Each single board reserves a shared physical memory for other boards, which is mapped to the CPCI bus through the PCI bridge, and then mapped to the PCI storage space of other boards through the PCI bridge. When other boards access this PCI storage space , the physical memory of the source board is actually accessed. It can be seen that the mapping of the PCI bridge achieves memory sharing between different boards.

Figure 2(c) shows the mechanism of implementing PSM inter-frame communication using UFIU. The design idea of UFIU's underlying communication module is similar to that of CPCI. It is also based on shared memory and CPCI address space mapping. The difference is that UFIU's communication module is implemented based on the mode of ATM server + client. In terms of connection mechanism, UFIU is connected to ATM optical network through optical interface, and realizes communication with other PSM boxes or nodes under the mode switching of ATM server + client. Inside the PSM box, UFIU communicates with each UGPU board to realize the function of sending and receiving data of each UGPU board by sharing memory. Each UGPU board reserves a certain amount of shared memory for UFIU. Through the aforementioned CPCI address space mapping method, it can be accessed by other CPCI boards, including the UFIU daughter board on the URCU board. When the UFIU receives data from the optical port, the Segmentation and Reassemble (SAR) dedicated processing chip of the ATM adaptation layer (ATMadaptation layer 5, referred to as "AAL5") on the UFIU board, such as the model CN8236 ASIC chips, etc., directly access and store in the UFIU receiving shared memory area of the corresponding receiving UGPU board; when the data of each UGPU board is sent out of the PSM box, it only needs to be copied in the UFIU sending shared memory area, and the UFIU board The SAR dedicated processing chip on the device is automatically taken out and forwarded to the ATM network through the optical interface.

In the ATM network that bears the interconnection between PSM frames, the ATM switch uses the virtual channel (Virtual Path, referred to as "VP") indicator VPI and virtual channel (Virtual Channel, referred to as "VC") indicator VCI in the header to find the path. . In terms of composition, one VP bears multiple VCs, so a VP can be regarded as a collection of multiple VCs with the same VPI value. VPs have different VPI values, VCs belonging to the same VP have different VCIs, and VCs belonging to different VPs may have the same VCI value. Usually, VC can be used to directly complete the connection between two users, and VP can be used for the connection between different network segments. VP switching only switches the VPI, and the VCI of the cell remains unchanged during the transmission of the entire VP link. The VC is connected at the switching node, and looks up the mapping table according to the VPI and VCI of the cells in the virtual path to obtain the corresponding new VPI and VCI.

Since the network structure between PSM frames is relatively stable, Perpetual Virtual Channel (PVP for short) and Perpetual Virtual Channel (PVC for short) are generally used. The establishment of PVP and PVC is based on expected needs It is accomplished by pre-specifying the VPI/VCI of the corresponding connection and the mapping relationship between the input VPI/VCI and the output VPI/VCI at each switching node.

During communication between PSM frames, different VPIs are generally used to indicate different PSM frames, and different boards in the frame are represented by VCIs. Therefore, on the UFIU board, the VCI pathfinding function must be completed, that is, to map the VC channels of each board, which is realized by mapping the sending VCC table (SEG VCC) and receiving VCC table (RSMVCC).

In the shared memory address area on the SAR dedicated processing chip of UFIU, the sending and receiving queues, SEG VCC table and RSM VCC table of the URCU board and each UGPU board in the same frame, as well as the description of the sending buffer (Send Buffer Descriptor, referred to as "SBD") are allocated. ”) tables, etc. In the shared memory address area of the URCU, it is mainly allocated the operation, administration, maintenance ("OAM") cells and data cells of the URCU to send and receive data buffers, status queues for sending and receiving, and UGPUs in the same frame The board's transmit data buffer. In the shared memory address area of each UGPU board, local send and receive buffer descriptors, send and receive status queues, local SEG VCC tables and RSM VCC tables and receive data buffers are allocated.

The SAR special processing chip of UFIU mainly relies on the VCC table to send and receive ATM cells with the outside world. The sending VCC table is located in the shared memory of the SAR. Each board is allowed to create up to 256 sending PVCs, and the index value of the entry is the sending VCC index; for the receiving VCC table, each board is allowed to create up to 256 receiving PVCs. The index value of the entry is the receiving VCC index. One VCC index corresponds to one VPI and VCI link. The PVC configuration of the UFIU is to establish a corresponding relationship between the VCC index and the PVC for the inter-chassis transmission and reception of the single board, that is, the mapping relationship between the VPI, the VCI link and each single board. The PVCs of the UFIU boards all use unidirectional PVCs, so the establishment and removal of the sending PVC and the receiving PVC are independent, and the index numbers of the two are also assigned separately.

It can be seen that under inter-frame communication, the PSM frame needs to be addressed through the corresponding relationship between the VCC index in the VCC table and the PVC, that is, the sending PVC is indexed according to the physical slot number of the host sending VCC table; the receiving PVC is configured according to the The logical slot number performs index configuration on the host receiving VCC table. When the switching occurs, the external ATM switching will not change, that is, the VCC index corresponding to the VPI and VCI link cannot be switched, so the actual switching is the corresponding relationship between the VCC index PVC channel, that is, the VCC item and the receiving physical slot The corresponding relationship of numbers to change the flow direction of received data units.

In one embodiment of the present invention, the switching method based on CPCI shared memory communication is implemented by using the mapping conversion relationship between logical slots and physical slots. The system assigns a logical slot to each single board on the bus, and the high-level application accesses the corresponding single board through this logical slot. Bit mapping table, which reflects the corresponding logical slot assigned to each board at the physical location. During the communication process, the CPCI underlying driver module indexes the single board at the physical location according to the table. In the initial state of the system, the logical slots are consistent with the actual physical slots of the board. The high-level application module transmits the data unit and the logical slot of the target board to the CPCI bottom-layer driver module. According to the logical slot, the CPCI bottom-layer driver module is It can search the logical slot and physical slot mapping table, convert it into the actual physical slot of the target board, and then convert it into the corresponding CPCI space address of the shared memory through the shared address space mapping of the PCI bridge for access. The logical slot and physical slot mapping table mechanism is directly related to the bottom layer of the PSM frame, and can be completed by direct index search, so it has no impact on the efficiency of CPCI communication.

When one or more single boards are switched, it is only necessary to modify the logical slot and physical slot mapping tables on all the single boards to equivalently realize the switching of single boards. For example, if the logical slot number 1 of the original main board to be switched is mapped to its physical slot number 1, and the logical slot number 2 of the standby board is mapped to its physical slot number 2, the two single boards When board switching occurs, change the mapping table so that logical slot number 1 is mapped to physical slot number 2, and logical slot number 2 is mapped to physical slot number 1, that is, the switching operation of the active and standby boards is equivalently completed. In the same way, the switching operations of other standby modes can also be realized conveniently. It can be seen that the switching method is not only convenient to operate, but also can be completed at a high speed. Before and after the switching operation, the service communication is hardly affected, which ensures the normal communication of the service.

In a preferred embodiment of the present invention, a centralized control method is adopted to realize the switching operation, so that the switching of the equipment unit is simpler and more reliable. For example, in the aforementioned PSM box, the CPCI control board URCU centrally controls the logical and physical slot number mapping tables of all boards, and each board also puts the logical slot and physical slot mapping table in the shared memory of the board , is modified centrally and synchronously by the URCU board to ensure the normal operation of the entire communication system.

In another embodiment of the present invention, each single board also saves its own logical slot and physical slot information, then when modifying the logical and physical slot mapping relationship table, it is necessary to modify the relevant switching unit Its own logical slot information saved in the board. For example, when the board in physical slot No. 1 and the board in physical slot No. 2 mentioned above are switched, in addition to all mapping tables needing to be modified, the logical slot number stored on the board in physical slot No. 1 The original No. 1 needs to be changed to No. 2, and the logical slot number stored on the board of the No. 2 physical slot needs to be changed from the original No. 2 to No. 1.

According to the above content, FIG. 3 shows the specific flow of the switching method implemented by modifying the logical slot and physical slot mapping table according to an embodiment of the present invention. This method is applicable to the switching of various single boards on the bus, including control single boards and equipment single boards.

In step 301, the control board updates the logical slot and physical slot mapping table on the board according to the board switching mode. For example, in the PSM box, the URCU modifies the mapping table stored by itself.

Then enter step 302, control the single board to synchronize the updated logical slot and physical slot mapping table content to the logical slot and physical slot mapping table on all single boards. For example, in the PSM box, URCU then modifies the mapping table on each UGPU board. When modifying, match the logical slot number of the originally active board with the physical slot number of the original standby board, and match the logical slot number of the original standby board with the physical slot number of the original active board numbers correspond. Other single boards send data through logical slot numbers. When the data arrives, the control single board can send the data to the master single board after switching according to the corresponding relationship in the mapping table.

Then enter step 303, the control board updates its own logical slot information stored on each board involved in the switching.

In one embodiment of the present invention, considering the inter-frame communication, the external interface board of each frame stores a channel information mapping table for single-board data unit forwarding. The channel information mapping table here is the information used by the external interface board to index the physical slot number of the single board in the frame according to the channel number for external communication. In the PSM frame, it is the aforementioned sending VCC table and receiving VCC table. When switching occurs, the information needs to be modified to ensure the normal operation of inter-chassis communication. For example, in the aforementioned PSM frame, the UFIU interface board based on the ATM optical interface stores information such as the receiving VCC table and the sending VCC table, and based on these information, the data units of each board are indexed and forwarded to complete inter-frame communication. Therefore, when board switching occurs, after updating all logical and physical slot tables according to the aforementioned switching method based on the logical and physical slot mapping table, it is also necessary to modify relevant information such as the sending VCC table and receiving VCC table; During switching, a bus switching operation is required to transfer the control right of the bus to the standby board, and update the information stored on the original active control board to the standby board. It should be noted that the information update of the active and standby boards during the switchover of the control board is mainly information related to the control board itself, such as the modification of the sending and receiving channel mapping table of the active and standby control boards and the communication channel mapping table between the active and standby boards . The channel mapping table related to the UGPU single board is synchronized with the active and standby control boards during normal operations (configuration/deletion/UGPU board switching), so the information does not need to be updated when the control boards are switched. In addition, because both the device board and the control board are equipped with ATM driver modules, and different ATM driver modules need to communicate with each other, the underlying driver module communication is also realized through shared memory, specifically, through the previous The corresponding control command word address is implemented by writing the control command word, so it is necessary to modify the corresponding control command word address when switching occurs. It can be seen that the additional switching operation required under the framework communication only involves the bottom driver module of the interface board, which is simple, reliable and has good real-time performance.

Under the inter-chassis communication, the processing steps are different when the control board is switched and when the equipment boards are switched. Fig. 4(a) shows a method for controlling switching of a single board realized by modifying a channel information table under inter-frame communication according to an embodiment of the present invention.

In step 411, bus control switching is performed, the original active control board releases the bus control right, and the original standby control single board takes over the bus control right. For example, in the PSM frame, the original standby URCU is in the bus disconnection state. When a switchover occurs, the original active URCU transfers the bus control right to the original standby URCU through handshaking.

Then enter step 412, and update the channel information table corresponding to the control board on the active and standby control boards. For example, in the PSM frame, when the URCU board is switched, it is necessary to update information such as the sending VCC table and receiving VCC table of the active and standby URCUs, and these sending VCC tables and receiving VCC tables are stored on the URCU. The sending VCC table and receiving VCC table contain the base address of each board’s transceiver data storage area. The so-called base address refers to the basic address. You can find the starting The situation of the existing data in the storage area is calculated to obtain the location where the current data that needs to be sent and received should be stored. By mapping the logical slot number of the original active control board to the base address of the sending and receiving data storage area of the original standby control board, the data sent to the original active control board is now sent to the original standby control board, thereby Implement switching.

Then enter step 413, prohibiting the original active control board from being allocated to receiving channels of each device board. For example, in the PSM box, the original master board controls the UGPU board on the URCU board, so it cannot be assigned to the receiving channel of each device board.

Fig. 4(b) shows a method for switching equipment boards (other boards except the control board) by modifying sending and receiving channel information under inter-frame communication according to an embodiment of the present invention.

In step 421, the channel information table corresponding to the equipment boards involved in the switchover stored on the active and standby control boards is updated. For example, in the PSM box, it is necessary to update information such as the corresponding sending VCC table and receiving VCC table of the UGPU involved in the switchover stored on the active and standby URCUs. As mentioned above, information such as the sending VCC table and receiving VCC table of all UGPUs are stored on the URCU, and each UGPU also stores information such as its own sending VCC table and receiving VCC table.

Then enter step 422, update the control command word address information on the device board involved in the switchover, where the control command word address is used to realize the shared memory communication between the underlying driver modules. For example, in the PSM frame, the underlying ATM driver modules of the UGPU board and the URCU board need to write the control command word to the control command word address to achieve communication, so the corresponding control command word address needs to be updated during switching.

Then enter step 423, the control single board modifies the sending channel information and receiving channel information of the active and standby equipment boards involved in the switchover. The sending channel information and receiving channel information here are similar to the role of its own logical slot number for each single board.

In practical application, in order to ensure smooth switching, generally before the switching, it is necessary to check whether the active and standby boards involved in the switching are in use.

Those skilled in the art can understand that in addition to the CPCI platform or PSM frame, in other communication systems based on shared memory communication, the switching method provided by the present invention can be used to realize device switching without affecting the essence of the present invention and range.

In the embodiment of the present invention, the cascading scheme between PSM frames is mainly realized by using UFIU subboards and ATM optical interfaces. Those skilled in the art can understand that other physical interfaces are used to realize the connection between different PSM frames or between different CPCI buses. During communication, the switching method provided by the present invention can still complete equipment switching without affecting the essence and scope of the present invention.

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein, and without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

1. the reverse method in the communication system, described system comprises the polylith veneer, wherein comprises at least one control veneer, is used for carrying out shared drive communication by all described veneers of bus centralized control; Also comprise logical slot and physical slot position mapping table on the described veneer, be used to indicate the logical slot of all veneers and the mapping relations between the physical slot position, it is characterized in that described veneer comprises following steps in the time of need switching:

The described control veneer of A is revised logical slot and the physical slot position mapping table on all described veneers, and the logical slot of the veneer that the former former head is used number is mapped to the physical slot item of original standby veneer;

The described control veneer of B is revised the inherent logic slot number of being stored on described original primary and backup veneer.

2. the reverse method in the communication system according to claim 1 is characterized in that, described steps A also further comprises following substep:

The described control veneer of A1 is revised logical slot and the physical slot position mapping table on this plate, the logical slot of the veneer that the former former head is used number is mapped to the physical slot item of original standby veneer, the logical slot of original standby veneer number is mapped to the physical slot item of the veneer that the former former head uses;

In logical slot that the described control veneer of A2 upgrades this plate and the physical slot position mapping table content synchronization logical slot and physical slot position mapping table to the every other veneer.

3. the reverse method in the communication system according to claim 1 and 2 is characterized in that, described communication system is based on compact interconnection bus of peripheral devices platform.

4. the reverse method in the communication system, described system comprises at least two frames of intercommunication mutually, each frame comprises the polylith veneer, wherein comprises at least one control veneer, is used for carrying out shared drive communication by all described veneers of this frame of bus centralized control; Described control veneer also comprises the channel information table, is used to preserve the mapping relations of logical slot number with the transceive data memory block plot of all veneers in the frame, it is characterized in that described control veneer comprises following steps in the time of need switching:

D carries out total line traffic control and switches, and former main with control veneer release bus control right, former standby control veneer is taken over described bus control right;

E updates stored in described former main with the channel information table on control veneer and the described former standby control veneer, with the described former main transceive data memory block plot that number is mapped to described former standby control veneer with the logical slot of controlling veneer;

F forbids described former main with controlling veneer to described equipment veneer distribution receive path.

5. the reverse method in the communication system according to claim 4 is characterized in that, when the veneer beyond the control veneer in the system is switched, comprises following steps:

G updates stored in the channel information table on the described control veneer, former main logical slot with veneer number is mapped to the transceive data memory block plot of former standby board;

H upgrades described former main with being used to realize shared drive control of communication command word address information between the bottom layer driving module on veneer and the former standby board;

The described control veneer of I is revised described former main with the inherent logic slot number of storing on veneer and the former standby board.

6. according to the reverse method in claim 4 or the 5 described communication systems, it is characterized in that, before switching, check and whether to switch the primary and backup veneer that relates to, switch if then begin all using.

7. according to the reverse method in claim 4 or the 5 described communication systems, it is characterized in that described communication system is based on compact interconnection bus of peripheral devices platform.

8. according to the reverse method in claim 4 or the 5 described communication systems, it is characterized in that, can communicate by asynchronous transfer mode between the described frame.

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