Analysis of core technologies of broadband routers (1)

With the development of networks, broadband routers are widely used. A Broadband Router provides a perfect solution for network sharing. As an Access Router, A Broadband Router initially aims to achieve network sharing. Broadband routers ensure the speed requirements of users while ensuring low prices. What is the performance of a large number of vrouters on the market? How to purchase? Generally, the performance and grade of a router are determined by the processor, memory, and cache.

Vro Processor

Like a computer's CPU, the processing chip of a router is the core component of a router and a key component that directly affects the performance of the router, the quality of the processor often determines the throughput of the Broadband Router, which is the most important parameter. Therefore, I will analyze the router chip here.

If the processor clock speed is less than m, such a Broadband Router is suitable for common household and SOHO users. 100M-200M is a medium frequency. More than M is a relatively high frequency, suitable for Internet cafes, small and medium-sized enterprise users and branches of large enterprises.

In low-end and Middle-end broadband routers, the processor is responsible for exchanging route information, finding route tables, and forwarding data packets. the processor's capabilities directly affect the router's throughput route table query time) and the route computing capability affect the network route convergence time ). In high-end broadband routers, packet forwarding and look-up are usually completed by the ASIC chip. The processor only implements routing protocols, computing routes, and distribution route tables. Due to the development of technology, there are many types of vro processors.

Generally, a vro processor is an embedded processor. It mainly uses x86, ARM7, arm9-, RDC, and MIPS architectures. The ARM7 and RDC architectures have already been eliminated. The performance of the processors using these two architectures is poor, and mainstream manufacturers are no longer using them. At present, the kernel processor using the arm9-and MIPS architecture is the mainstream configuration of the Broadband Router. The common 920 T, 922 T, T, 940T, and enhanced e, 946E, and 966E are classified into 2 K, 3 K, and 4 K Series, the performance of different processors varies greatly. Intel Xscale kernel processor is an advanced network processor for high-end products. Generally, a single processor is used, and a multi-processor is used for distributed processing. It features high performance.

Of course, the processor of A Broadband Router is only a component of a Broadband Router, especially because it is the core device. The processor performance of a Broadband Router does not fully reflect the router performance. The performance of a Broadband Router is reflected by the router throughput, latency, and route computing capability.

The performance of the vro is poor, but the performance of the vro is poor, but the performance of the vro is not necessarily good. The processor clock speed is only a performance indicator of the processor. To know the processor performance, you must also know whether its bus width is 16-bit or 32-bit), Cache capacity and structure, internal bus structure, single CPU or multi-CPU distributed processing, computing mode, etc., will greatly affect the performance of the processor.

Vro memory

A vro may have multiple types of memory, such as Flash memory and DRAM Dynamic Memory. The memory is used for storage configuration, router operating system, and routing protocol software. In the middle and low-end routers, the route table may be stored in the memory. Generally, the larger the vro memory, the better, the lower the price ). However, similar to CPU capabilities, the memory does not directly reflect the performance and capabilities of the router. Because efficient algorithms and excellent software may greatly save memory.

Generally, there are four types of vro memory:

I. read-only memory ROM)

Similar to ROM in a computer, vro is mainly used for system initialization and other functions. As the name suggests, ROM is a read-only memory and the code stored in it cannot be modified. To upgrade, replace the ROM chip. ROM mainly includes: system power-on self-check code POST), used to check whether all hardware parts of the router are in good condition; System Boot Code BootStrap), used to start the router and load it into the IOS operating system; the backed up IOS operating system can be used when the original IOS operating system is deleted or damaged. Generally, this IOS version is lower than the current version running IOS, but it is sufficient to support vro startup and work.

Ii. Flash)

It is a readable and writable memory that can still store data after the system is restarted or shut down. Flash stores IOS currently in use. In fact, if the Flash capacity is large enough, you can even store multiple operating systems, which is very useful for IOS upgrades. If you do not know whether the new version of IOS is stable, you can retain the old version of IOS after the upgrade. When a problem occurs, you can quickly return it to the old version of the operating system to avoid long-term network faults.