The role of high traffic in production testing of broadband communication products

1. Introduction

Modern communication bandwidth is growing rapidly, and the corresponding communication product system structure is becoming more and more complex: high-speed interface and backplane bandwidth, high-density ports and system layout, and high reliability. With the increase in the complexity of communication products, there are more and more types of product failures, and the failure rate is also increasing. In order to provide the best products to users, communication manufacturers need to test new components and increase the testing pressure in the production stage so that failures can be discovered in the production stage and poor performance products can be prevented from being sent to users, so as to eliminate the impact on the company's product reputation and reduce subsequent maintenance costs. In addition, due to the increase in product complexity, users pay more attention to the manufacturer's production test guarantee in addition to the function. In other words, communication manufacturers must improve the test coverage of their products.

This article focuses on the necessity of conducting high-flow testing in production in order to improve the test coverage of modern communication products, so as to provide a reference for communication equipment manufacturers.

2. What modern broadband products need to be tested for

Production testing is to ensure that all boards (circuit boards, switch boards, main control boards, interface boards) of communication products and all hardware components on the entire system can work normally.

The following takes a typical broadband communication product system as an example to introduce the test items that each function card focuses on:

Figure 1. Broadband communication product system structure

2.1 Line interface card & Line processing card

Test items involved in processing card

-Optical module, light transmitting/receiving function, light receiving sensitivity

- Clock recovery function

-Sonet/SDH alarm

-Internal clock unit

-Ethernet functions (various rates, working modes, Ethernet interfaces and forwarding chips)

- Input queues and buffers (internal chip or external FIFO or RAM)

-CPU mini-system and communication channels and interfaces with other cards

-Transfer table (various RAM, CAM, etc.)

- Output queues and buffers (FIFO and RAM)

-Packet processing capability (packet loss rate, packet delay, error packet processing, whether it can reach line speed)

- Connection relationship between modules within the board (short circuit, open circuit, etc.)

2.2 Test items involved in the main processing card

-CPU mini-system and communication channels and interfaces with other cards

- The processing power of the main control board, whether it can process information quickly and correctly

-Control channel function

- Whether the interface rate with other modules can reach line speed

-Log storage and console interface

2.3 Test items related to switch fabric card

- Test whether the packets from each port can be exchanged at the maximum speed

- Input and output buffers inside the switching chip

-On-board control systems and peripherals

-Interface with other boards

3. The role of high traffic in production testing of broadband communication products

Xinertai Technology's long-term experience shows that reasonable traffic testing can greatly improve test coverage and test efficiency in communication product production testing, mainly in the following aspects:

——Increase strong pressure, find some processing problems (such as cold solder joints), and test the connection between different network chips

——Test the working condition of IC on the board under the most extreme condition

——The load is working at full load, and the fault of the board or product is found under the maximum power load

——Test the working conditions of the product at its highest performance

——Device stability test

——Test the circuit performance related to timing of the single board

——Problems caused by upgrades and version matching

——Strengthen early failure (bathtub curve)

——Large traffic shock can detect quality problems in communication chip batches

——Can detect performance degradation caused by product version changes

--Can detect packet queue or cache memory interface connection and chip performance

——Can detect the lookup table storage interface connection and chip performance

——Test the business processing capability of the circuit board by simulating real business traffic

——Detect processing capabilities in various working states or working modes

——Enhance the screening capability, improve the delivery quality, reduce the single board return rate, and increase the unpacking qualified rate

——Test backplane bandwidth

——Test the data exchange and clock synchronization of different network chips

——Save testing time

——Save test space

——Reduce testing costs

4. Conclusion

The high-flow test in the production process of communication products has good performance and is very necessary. The use of high-flow test in production testing can simulate the real high-flow user environment to the greatest extent, reduce the missed test rate, increase the product unpacking pass rate, and improve the product quality image.