A Campus Network Optimization Scheme Based On 10g Epon Technology

With the rapid development of informatization in the whole society, the demand for information in colleges and universities has become more and more intense. College campuses are developing in the direction of digitalization and intelligence. Campus users have continuously increased requirements for campus network bandwidth and stability.

In the traditional local area network (LAN) networking mode, it is relatively easy to form a bandwidth bottleneck at the aggregation node, resulting in network instability and affecting the experience of using the network. If it cannot be resolved for a long time, it may cause complaints from campus network users and even form Internet public opinion, unstoppable.

Therefore, the school network management department must carry out network transformation for such buildings to eliminate bandwidth bottlenecks and improve the network experience. How to effectively improve the network bandwidth by utilizing various existing resources in the shortest time and at the lowest cost has become an urgent problem to be considered and solved. As a new generation of access network technology, Ethernet Passive Optical Network (EPON) technology has many advantages such as flexible networking, high service security, long transmission distance, and high bandwidth. Fully meet the needs of various business access in the smart campus.

10G EPON Explained

Source: thunder-link.com

In the development history of more than 20 years since the emergence of PON, a series of products such as narrowband PON, APON/BPON, EPON, and GPON has been formed. Among them, EPON, that is, the passive optical network based on Ethernet, is an important part of optical access technology. The specific features are: first, it adopts the Ethernet frame structure, which is naturally compatible with traditional Ethernet; PON network topology.

At present, the standards that are widely using PON access technology in the operator network are mainly the 10G EPON standard and 10G GPON (namely XPON) standard. Among them, 10G EPON technology, as a relatively mature technology in the next-generation PON technology, is more in line with the requirements of modern society for the development of communication networks in some respects.

Because it has the advantages of high bandwidth, high splitting ratio, natural compatibility with EPON, and smooth upgrade on the basis of the original network management. Since 10G EPON is in the same line as EPON, it has almost increased the network speed of the previous generation PON network by 10 times, perfectly matches the broadband planning of several major domestic telecom operators, and can support the medium and long-term network construction planning goals of major domestic telecom operators.

The realization of the solution can also vigorously support the continuous expansion of communication operators in Internet data center (IDC) business, government and enterprise customer business, and home customers, etc., especially suitable for network construction scenarios of fiber-to-the-home (FTTH). It is precisely because of its series of advantages, coupled with its lower cost than traditional Ethernet and its natural compatibility with Ethernet, that it becomes a promising choice in the process of campus network local network transformation.

Application Scenarios of 10G EPON in Campus Network Transformation

Source: forum.huawei.com

The traditional campus network mostly adopts the Ethernet 3-layer architecture (core layer, aggregation layer, and access layer), in which the core layer equipment is generally located in the central computer room, and the aggregation and access layer equipment are located inside each building, which belongs to the typical FTTB networking mode.

With the continuous development of informatization, this traditional active network gradually has obvious bottlenecks in network throughput performance, especially in student dormitory areas where Internet users are particularly concentrated.

Generally speaking, different areas within the school have great differences in building structure, network service types, bandwidth requirements, etc., and the network design also needs to consider adopting corresponding methods according to different characteristics to realize the access of various network services.

The campus student dormitory area is a user-intensive area, and has the characteristics of large number of concurrent users, high bandwidth requirements, and concentrated traffic during busy hours, and a considerable number of users who often use real-time services (video, games, etc.) have requirements for network quality Relatively high, the traditional Ethernet is difficult to fully meet the needs of the network.

Source: semanticscholar.org

There are two modes of networking that can be selected: fiber-to-the-corridor and fiber-to-the-room: For new dormitory buildings or old dormitory buildings with less difficulty in network transformation, it is more suitable to use FTTH networking.

The security of using this method of networking better and higher bandwidth, which can better meet the current and future needs of various network business applications; and for old dormitory buildings where it is difficult to renovate the wiring in the building, and the remodeling time and budget are relatively tight, according to the existing line resources It is more suitable to use the fiber-to-the-brick (FTTB) networking method, which can make good use of the original lines and quickly realize the provision of various network services.

The student dormitory area involved in this campus network optimization scheme contains a total of more than 1,300 dormitories, each with 4 Ethernet ports, a total of more than 5,000 campus network users, 141 access devices, and 5 aggregation devices, that is to say On average, each aggregation device needs to bear the uplink traffic of about 28 access devices.

The configured switches (including aggregation switches and access switches) are Gigabit switches, and at the same time limited by the current fiber resources, the network status in this area can only be 1G (access layer) or 2G bundled (aggregation layer) In the uplink, access switches are stacked in the form of 4 to 5 sets, with 24 to 48 ports in a mixed stack, and the number of switch ports in each stack is about 150. Obviously, this is a typical FTTB networking mode.

Source: researchgate.net

However, most of the current network applications are based on the cloud, and most of these network applications have relatively high bandwidth requirements, such as video on demand and live broadcast. Coupled with the application and promotion of high-definition video and content acceleration systems, users can obtain resources in the campus network at a very fast speed, so fast that the bandwidth on the user side can basically be fully utilized.

As a result, many campus network users report frequent network disconnections in this area, especially during peak periods of network use. After the technicians went to the site to check and analyze carefully, it was determined that the problem was indeed widespread, and further analysis revealed that the root cause of the problem was the bottleneck of network bandwidth, especially the bottleneck problem on the aggregation switch side.

To sum up, the network transformation of this dormitory area is imperative. In addition to the PON solution mentioned above, there was another popular alternative at that time, that is, the flattened network transformation solution. Simply put, it is to abandon the original aggregation switch settings and let the access switches directly connect to the core high-speed switches in the data center computer room. The flattened network transformation scheme has its obvious advantages, especially it can better solve the bandwidth bottleneck problem of the aggregation equipment, but a more obvious disadvantage of this scheme is also well known, that is, it is expensive and complicated to construct.

Source: theteche.com

Because this transformation plan will involve the procurement of a large number of core high-speed switches and their boards and the deployment of optical fiber links, and, combined with the characteristics of the school’s network construction at that time, the campus network infrastructure has basically taken shape, and the new laying Optical cables are difficult, expensive, and take a long time, and will cause damage to the school’s existing roads and building interiors, affecting the normal work and life of teachers and students in the school. Therefore, it is necessary to use the existing pipeline and optical fiber resources in the campus network as much as possible for transformation.

Because of the above situations, after comprehensive consideration and research by the school’s information department, it was decided to try to introduce the 10G Epon technology mentioned above to carry out the regional transformation of the campus network.

The specific transformation method is: to remove the original aggregation equipment (which can be reused for other regional network construction and reconstruction projects) and deploy 10G EPON, 10G optical module (click here)related equipment, and chains between the core switch and the access switch stack group.

Road, that is, OLT, ONU, etc. In this case, the theoretical bandwidth support capability that can be obtained by the uplink of the stack group of 5 to 6 access switches reaches 10G, which is greatly improved compared with the solution before the transformation.