Ethernet VS PON network: Which one is more suitable for enterprise campuses?

The trend of optical fiber replacing copper fiber reflects the changes of the times and the progress of technology. Since 2009, optical fiber technology has already penetrated into every corner of people's work and life. The all-optical network has a certain future. For the enterprise market, how to choose a suitable all-optical network solution has always been a hot topic in the industry.

In the process of doing a project, the most important thing in choosing a solution is to start from the application scenario.

I have had in-depth discussions with many owners about whether the PON solution can meet their needs. The characteristics of the PON solution are that the upstream and downstream bandwidths are different. The downstream broadcast and upstream TDMA (time division multiplexing) transmission modes transmit the data streams of different users in time division to achieve bandwidth sharing. The characteristics of the PON solution are both advantages and disadvantages. The advantage is that the communication problem is solved by splitting light, but the problem is that all traffic must be forwarded through the OLT. This mode is suitable for application scenarios with vertical traffic characteristics, but not for horizontal traffic application scenarios.

For example, when I was working on a hospital project covering an area of ​​more than 200,000 square meters, the local government proposed the direction of optical network guidance. The owner was first recommended the PON solution, but also expressed concerns. The owner said, "If the PON solution is used, I will have to build another dedicated network to meet the needs of the remote video teaching scene in the hospital operating room." Because the camera images in the operating room need to be projected on the on-site display screen for doctors to watch, the on-site cameras belong to horizontal traffic, and it is impossible to transmit the images to the background, go around and come back to display them on site. What if it affects the effect? ​​In addition, doctors need to hold meetings in the medical office before making rounds in the ward, and make analysis and summaries after the rounds. Document printing cannot use network printers. It is still a horizontal traffic problem that cannot be solved by the PON solution.

In addition, similar situations have occurred when doing school projects. For example, when students are in class, the blackboard projects real-time teaching images, which is a typical horizontal traffic scenario. Therefore, the actual needs of the owner are the basis for selection, and Ethernet color light technology is the user's own scenario needs. After communicating with the school's technical staff, the other party also recognized the Ethernet color light solution. In addition to the problem of application scenarios, if the PON solution is used, there will be management problems of two systems, and the Ethernet color light network has good compatibility, so there is no need to worry about this problem.

Left: Ethernet Color Optical Network Right: PON Network

From the perspective of architecture, the ONUs in the PON network share the bandwidth of the OLT, while the access switch to the passive aggregation in the Ethernet color optical network has exclusive bandwidth. The horizontal traffic mentioned in the above scenario refers to this kind of fast and reliable access method similar to the information point in the room. Therefore, compared with PON, Ethernet color optical technology has significant advantages in the horizontal traffic scenario.

Considering the complexity of the campus environment, it is difficult to expect to solve all problems with only one technology. The application of the solution is not universal, but should be based on the characteristics of the project and the user's scenario. In addition, during the design process, the owner will also be concerned about the cost. Under the traditional network solution, the general horizontal copper cable is calculated according to the average value, and the demand for each point is at least 50-60 meters; while the Ethernet color light solution is adopted, the line distribution is based on the area as the node, and the room/entry switch is the center. The average copper cable usage is about 15 meters, and the copper cable usage is reduced by at least two-thirds. According to actual experience, the cost of a single point of copper cable is 600-800 yuan, and the newly built scene has thousands of points. After adopting the Ethernet color light solution, the cost of the comprehensive copper cable will definitely be reduced.

Application scenario requirements and characteristics

Colleges and universities: Multiple business types, complex networks, and dense terminal users

Primary and secondary schools: multimedia, high-frequency video teaching, recording and broadcasting and other services require high bandwidth

Hospitals: Electronic imaging, electronic medical records and other services require bandwidth and high availability, mobile ward rounds, smart infusion, and asset management

Enterprise: Office, design, production, manufacturing and other different levels of network requirements and collaborative office requirements

Government: Multi-export and multi-level requirements, network security, and management and operation requirements

Cultural and museum venues: venue-owned business systems, venue operation support systems, public security, public Internet, etc.

Transportation: Office business, production system business, public place Internet access and other different needs

Sports venues: unique event systems, business systems, office systems and public venue Internet requirements

In general, scenarios with high bandwidth, complex logical networks, and complex lateral traffic and access control relationships are suitable for network design, deployment, and operation and maintenance based on Ethernet technology architecture.

When designing a plan, I think the following points need to be considered from the user's perspective.

1. The practicality and advancement of the solution. Ethernet optical network supports 10G~400G high bandwidth, responds to the trend of optical fiber replacing copper fiber, and has a long service life, high speed, long transmission distance and low latency.

2. Stability and reliability: using industry-level network hardware equipment, low failure rate, stable and reliable, and key equipment using hardware backup, redundancy and other reliability technology designs;

3. Flexibility and scalability. Ethernet color optical network supports the upgrade of various network transmission, business or usage requirements, without the need to rewire to the weak current room, and has strong expansion capabilities;

4. Economic efficiency and standardization: Make full use of the investment in funds and technology, based on international standards and relevant standards issued by the state and associations. The "Technical Specifications for the Construction of Ethernet All-Optical Networks in Smart Parks" currently issued by the China Construction Industry Association is the first standardized document on the construction of smart parks;

5. Easy to manage. The Ethernet architecture is adopted, which continues the existing operation and maintenance knowledge system of most information center personnel, greatly reducing the cost of network construction and use. In addition, the middle layer of the Ethernet all-optical network is passive, and the weak current room no longer needs gas fire extinguishing and air conditioning cooling like the traditional solution, which greatly reduces the operation and maintenance pressure of the weak current room.

6. Security: Ethernet optical network naturally has the advantages of mutual access and flexible security isolation on demand, and has better business carrying and security protection capabilities.

From the designer's perspective, first of all, Ethernet color light network is basically the same as traditional Ethernet, which is smooth for designers, and most of the original drawing habits and drawing templates can be used, and the learning conversion cost is relatively low; secondly, the solution is suitable for scenarios with more horizontal businesses such as hospitals and schools, meeting the short-term and medium-term development needs of the business, helping to highlight the design highlights and demonstrate the design value; finally, the Ethernet color light solution can more calmly deal with complex changes in the design, and through standardized and modular design, it helps to simplify the design work and reduce the design workload.

Ethernet color light technology is a practical need for users in the "optical fiber optic cable replacement" scenario, and has already had many practical examples in the construction of smart parks such as smart education, smart medical care, and smart enterprise parks. As long as it is beneficial to the project and the users, and can be combined and matched with national policies, it is our responsibility as a designer. We must make good use of this technology and promote it. The future of Ethernet color light network requires the full combination of design units, construction units, research units and manufacturers, and the integration of "production, learning, research and application" to inject more lasting genes into the high-quality development of the smart building industry.