Abstract: The distributional structure is widely applied in the core router and so on the large-scale system, the ethernet is in the distributional system between each subsystem the information transmission good platform. This article unifies the project practice, proposes in the distributional system interior ethernet the MAC address and the IP address one new dynamic collocation method. Proved through the practice that this method has the disposition nimbly, the nurse resources to buckle characteristics and so on easy large scale production.
Key word: Distributional system embedded structure ethernet IP address dynamic disposition
Introduction
The ethernet by its simple nimble, the mature stable characteristic becomes many distributional systems [-] the internal communication first choice way. In these system interior uses in the ethernet structure, how to use and the disposition address message reasonably (including the MAC address and the IP address) becomes enhances the system usability and the flexible key.
In OSI seven network protocol reference model, 2nd for data link layer. MAC address located at this level, it by network equipment manufacturer production when writes in the hardware. The MAC address uses 6 bytes 48 generally, first 24 are produces network equipment’s manufacturer to the IEEE application manufacturer address, latter 24 assign voluntarily by the manufacturer. Such assignment enables in the world random to have 48 MAC address network equipment to have only marking.
In the TCP/IP network, each main engine has the only address. IP agreement request when each time with TCP/IP network establishment connection, each main engine must for this linked allocation only address (IPV4 be 32, IPV6 is 128). This assignment is called the IP address for various main engines’ address. It divides into the interconnection on-line public IP address and the confined on-line internal IP address two kinds.
The distributional system’s internal structure to the user is completely transparent, its interior uses the embedded structure generally. In the embedded structure’s address message solidifies generally in non-erasable storage ROM, when system initiation autoloading these information. This kind of address disposition pattern is quite general, suits in the general distributional system; But regarding certain complex distributional systems, this kind of pattern possibly brings some questions, like increases the production cost, the production cycle to be long, the debugging process to be complex, the working efficiency is low as well as the address availability of resources low status. This article unifies the actual project, proposed that in the distributional system interior ethernet the MAC address and the IP address’s dynamic collocation method, has fundamentally solved the problem which the tradition collocation method brings. Following introduces the MAC address and the IP address dynamic collocation method.
1 project background
Country digital switching system engineering technology Research center (NDSC) has undertaken the national 863 project high performance IPv6 core router research and development work. This core router uses the distributional system structure, by the line card, the repeater, the exchange, master control and so on modules is composed. Its median line card, the repeater, the exchange module are called as the veneer module. These veneer module uses own embedded processor board the ethernet net mouth unit, passes the ethernet and the master control module is connected. Various processors board with the VxWorks embedded real-time operating system, may process various veneers module alone the real-time task. The master control module with the Linux operating system, has the good man-machine conversation window, may has the contact through the ethernet and various veneers module, its structure like chart l shows.
Because in the distributional system’s various veneers module needs carries on the correspondence through the internal ethernet and the master control module, must therefore give in various veneers module the embedded processor board net mouth unit assignment corresponding MAC address and the IP address. These address message general solidification when ROM, system initiation automatic read.
What here need pointed out that below discusses the MAC address and in the IP address disposition and the traditional significance’s allocation starting point is different. In the traditional significance’s IP allocation will be refers to through the DHCP agreement (dynamic main engine disposition agreement) (might be through server and in the Internet connected local area network’s computer) assigns on a Internet’s public IP address with the Internet connected computer, will enable it on-line uniquely to mark itself in the interconnection. Here discusses in the distributional system structure’s internal ethernet and the exterior network are isolate, does not need Internet’s on public IP allocation for various veneers module in embedded processor board net mouth unit. Various nets mouth unit only needs in the local area network interior uniquely to mark itself, only corresponds a local area network interior IP address; But the MAC address regarding each network equipment is only. How is the following discussion’s collocation method refers to gives the local area network internal IP address and the MAC address disposition each net mouth unit.
2 tradition static allocation method
According to the project design requirements, first need to apply for certain MAC address, simultaneously designates some local area network interior IP address (, because is internal ethernet, with outside is isolation, the IP address may also willfully designation). Then solidifies these MAC address and the IP address’s information in ROM, produces these ROM by the Manufacturer. After ROM leaving the plant, welds them on each embedded processor board carries on the debugging. This method has the following shortcoming:
①According to the MAC address and the IP address’s definition, on each processor board’s ethernet net mouth unit’s MAC address and the IP address are dissimilar. Cannot solidify the same address message in the middle of different ROM, therefore each ROM information is different, can only manufacture alone, cannot carry on the volume production. As the matter stands increased the cost, moreover the production cycle is long.
②Because manufactures good each embedded processor board the net mouth unit MAC address and the IP address is different, debugs when each embedded processor board must the differential treatment. Must therefore act according to the different address to establish differently separately matches believing
The rest, such debugging process is complex, the working efficiency is low.
③In the concrete application, to prevent equipment’s damage, the emergency apparatus is essential, therefore produces the embedded processor board integer needs to be more than the actual need quantity. Because on the processor board’s net mouth unit integer must with the processor board integer consistent, therefore needs to apply MAc address quantity must with processor board production quantity consistent, must be more than quantity which the normal work needs. If works the processor board to be able to work normally, does not need to use the spare processor board, such assigns for the spare processor board on the MAC address resources cannot obtain the application. when works the processor board to appear question needs to use the spare board, has the question processor board MAC address equally not to be able to obtain the application. Therefore is more than the work to need quantity the MAC address not to be able to obtain the application to waste surely.
In view of the above question, has used the dynamic collocation method to the core router project distributional system’s embedded processor board’s net mouth address message.
3 dynamic collocation methods
Flash might scratch writes the nature and the non-volatility obtained the widespread application in the now embedded system. Because time ROM leaving the plant the content has written decides, cannot change, therefore the complex embedded system may scratch generally using Flash writes the nature to carry on system’s disposition. As a result of the veneer module’s complexity, needs to adjust the embedded processor board the disposition information to guarantee its normal work, therefore, may use Flash fully the function, unifies effectively its and the ROM disposition. Adopts the following .MAC address and the IP address dynamic collocation method in the distributional router:
①Must measure according to the normal work applies for the MAC address (to compare with static allocation, does not have the spare MAC address), such resources may obtain the effective use.
②Establishes the embedded processor board embedded system to visit the MAC address and the IP address message order. The system initiation reads the ROM information, when reads the net mouth address message changes to Flash the relative address visit, if has the related information to read; If in Flash has not been related the information to read in ROM the address message, process as shown in Figure 2.
③From application to the MAC address in optional, simultaneously chooses a local area network IP address. Visit the MAC address and the IP address order information unification programming these hardware information and the embedded system solidify to each ROM, combines to make or become volume production these ROM. This may reduce the cost effectively, reduces the production cycle.
④Welds on separately each embedded processor board these ROM, and in the Flash related MAC address and the IP address message sets at the processor board on O, such processor board reads in ROM the address message to carry on the disposition. Because in each ROM MAC address and the IP address message is the same, therefore various processors board’s debugging process is the same. Such step is consistent, easy and feasible.
⑤After the processor board debugging finished, MAC allocation which applied for each veneer module different processor board net mouth; Simultaneously chooses some local area network IP address, guaranteed that they in the ethernet interior are only. Then may (under Linux with Minicom, Windows under with remote terminal) assign good hardware information and so on MAC address and IP address through the debugging aids writes about in the work separately on various processors board Flash. Through the above type of distribution, all work’s processor board took Flash in address the only MAC address and the IP address. When embedded system start went study has assigned for the respective address message. Then might carry on the processor board and various veneers module synthesis debugs.
⑥When works the processor board to appear the question needs to use the spare processor board, may appear the question on the processor board in Flash the MAC address and the IP address redistributes for the spare processor board. This effectively has used the MAC address resources which applies.
Through the above MAC address and the IP address’s dynamic collocation method, may overcome each kind of question which effectively in the static allocation method exists. Is opposite in the static allocation method, the dynamic collocation method unified F1ash and the ROM nimble application, has the following merit:
①Can measure production content consistent ROM in groups, reduces the system cost, reduces the production cycle.
②Each processor board’s debugging step is consistent, easy and feasible.
③Applies the MAC address obtains the effective use, saves the address resources.
Conclusion
In the distributional system the MAC address and the IP address dynamic disposition and static allocation’s basic difference lies in F1ash the nimble application. QHartus which is day by day widespread along with the distributional system’s application and the design day by day complex, the dynamic collocation method provides the low production cost which, the short production cycle and the high address availability of resources as well as the Jan company provides II and SOPC the Builder development kit may after completing interface function design, fast carries on system’s integrated design and the system simulation, may realize the overall system design finally on the Cyclone series chip which Altera provides. Programs to the Nios processor may, in does not change the system hardware frame in the foundation, increases system’s function and the processing efficiency conveniently, and develops again to system’s promotion has the very big convenience.
