Cainiao growth Manual: in-depth analysis of router technology (1)

Broadband Internet access is nothing new. People are no longer familiar with related network devices, such as common routers. See figure 1. For average network users, they feel satisfied when they know how to use a vro to access the Internet or play games. Generally, they have seldom asked questions about the deep technology of the vro, however, as a technology enthusiast with a wide range of interests, he is very interested in this knowledge.

However, due to restrictions on various conditions, none of these enthusiasts are developers. To a large extent, they are unable to gain a deep understanding of the real technology implementation process and related core information.

Based on this point, the author has made every effort to build a bridge that can connect to the deep core of technology-loving readers with the accumulation of his own knowledge to unveil the secrets of routers, cut off its core internal organs. In order to give readers a clear understanding, I try to convert the professional technical content into an easy-to-use knowledge explanation, which may be biased. Please forgive me.

Overview

What is a router?

Figure 1

The Internet is connected by routers, which are the core devices of the Internet or an IP network. The increasing bandwidth access has led to the increasing demand for routers.

What kind of technical product is vro?

When talking about the development of vrouters, we can't help but talk about the development of "embedded" devices. That's right. Generally speaking, vrouters are embedded products. So what is an embedded device?

As a matter of fact, embedded devices are constantly exploring every aspect of our daily lives. Generally speaking, an embedded device is a device or equipment that has a computer function but is not called a computer. It includes almost all the electrical equipment around us: PDA, mobile phone, set-top box, automobile, microwave oven, elevator, security system, vending machine, medical instrument, stereo audio, ATM, etc.

In more professional words, embedded devices are embedded devices that use microprocessor or microcontroller chip (MCU), peripheral circuits, and internal programs to implement specific functions. For example, 8-bit single-chip microcomputer, 32 ARM, and DSP chip all belong to the category of embedded core chip. The 8-bit MCU market has gradually stabilized, and 32-bit MPU represents the development direction of embedded technology and is accelerating development. In the 32-bit embedded microprocessor market, the ARM Kernel-based microprocessor is in an absolute leading position in the market, so it is particularly important to track the development trend of ARM technology.

Vro development is generally based on a 32-bit processor. Generally, low-end and Middle-end vrouters have multiple options for development configuration, for example, there are a variety of options, such as arm9-core chip + Wince operating system, arm7-core chip + uClinux operating system, DSP chip + Vxworks operating system. This article introduces common SOHO routers, and selects the development mode of the ARM7 core chip + uClinux operating system to explain the technical implementation process of the routers in a complete example.

Why are we introducing SOHO routers? What is a SOHO router? In the past, many families had more than one computer and needed to access the Internet to obtain information and send and receive emails. The number of computers for these small companies and home network users is generally small, and the network structure is not complex. Features and bandwidth requirements are not high. To improve network performance, share limited IP addresses, or save Internet access costs, these users urgently need cost-effective small routers. We call this small router a SOHO router. At present, the market is flooded with a large number of such low-end routers, which are very suitable for embedded systems due to the low cost of the chip series. Currently, most SOHO routers on the market use the ARM7 series Processors. However, due to the development of technology, the vrouters of the arm9-series dedicated Routing Chip are also becoming more and more popular.