China Telecom has completed the industry's first smooth upgrade test and verification of existing network equipment OSU, taking a crucial step towards the commercial scale of OSU

Communication World Network News (CWW): Recently, China Telecom's M-OTN (Metro optimized OTN)/OSU (Optical Service Unit) multi-service bearer technology completed the industry's first cross vendor and cross city smooth upgrade test of existing network equipment in Anhui Telecom, and opened the first Ethernet dedicated line service based on OSU technology for friendly customers. The test was successful. The success of this experiment not only marks significant progress in standardization, equipment development, and practical application of M-OTN/OSU technology, but also lays a solid foundation for the large-scale commercial use of M-OTN/OSU technology in the next stage.
Implementing the national strategy of "Network Power, Digital China", China Telecom actively promotes the high-speed ubiquitous "Cloud Network Integration 3.0", and collaborates with the industry to propose the first M-OTN technology system with OSU as the core. This makes up for the shortcomings of traditional OTN technology in carrying small particle businesses, such as low efficiency, delay drop, and difficulty in bandwidth lossless adjustment. It provides the next generation of metropolitan transmission networks with the ability to ensure high-quality business slicing requirements while also meeting low-cost requirements A comprehensive service bearer solution with low latency and low power operational requirements.
The current network experiment organized by Anhui Telecom focuses on verifying the large-scale deployment and long-term stability of equipment supporting M-OTN/OSU technology, including key technologies such as M-OTN/OSU multi-service mixed bearer, cross vendor networking, bandwidth lossless adjustment, low latency, and the ability of current network equipment and network management systems to smoothly upgrade OSU.
The topology of the current network experiment is shown in Figure 1, where the provincial backbone network spanning Huainan (A city) and Lu'an (B city) uses the current network backbone OTN network. The core layer and convergence layer M-OTN devices of Huainan and Lu'an metropolitan area networks are provided by ZTE, and the access layer M-OTN devices are provided by Greenwell and ZTE, respectively. Unlike the existing network pilot conducted using experimental equipment before, this current network trial uses commercial M-OTN equipment to verify the new and upgraded OSU introduction modes in two metropolitan area networks. The main achievements of this online test include:
Verified the ability of online devices to upgrade OSU without any business impact: By introducing OSU adapter cards or OSU business boards into existing OTN devices, it is possible to quickly and low-cost obtain OSU business capabilities; Not only can it fully utilize the existing circuit board and channel resources, protect existing network investments, but the upgrade process has no impact on online business.
Verified the ability of unified bearing for multiple services: By introducing a hybrid line card that supports both VC/ODU/OSU modes, it can achieve unified bearing for multiple services such as E1, STM-N, EoS, EoO, EoOSU, etc.
Verified the stability and reliability of the device: Through friendly customer trial experience feedback and long-term error rate and packet loss rate meter testing, it was confirmed that the device using OSU technology has the ability to operate stably for a long time, and the network runs safely and reliably.
Verified the fast lossless bandwidth adjustment capability: achieved second level lossless bandwidth adjustment in a complex multi vendor environment, with a minimum adjustment granularity of 2.5Mbit/s for business bandwidth, thus solving the problem of SDH LCAS and ODUFlex G.HAO's lossless bandwidth adjustment capability not being commercially available for a long time.
Verified the low latency characteristic: After adopting OSU technology, the business mapping mechanism and processing hierarchy were optimized, and the device processing latency was reduced. Compared to the current EOSoO bearer method used in OTN networks, the end-to-end circuit latency was reduced by 16% to 64%.
The current network testing equipment has followed the released "Technical Requirements for Metropolitan Area Optical Transport Network (M-OTN) Equipment" Chinese telecommunications enterprise standards. The successful testing of key functions such as OSU business and lossless bandwidth adjustment, and multi manufacturer interconnection fully demonstrates that China Telecom's leading M-OTN/OSU technology system is relatively mature. China Telecom is collaborating with companies such as China Unicom, China Academy of Information and Communications, ZTE, Huawei, and Fenghuo to enrich and improve standards, actively promoting the transformation of standards into industry and international standards.
At present, mainstream OTN equipment manufacturers such as Huawei, ZTE, FiberHome, Greenwell, and Riskonda are all able to provide commercialized M-OTN/OSU devices, marking the transition from technical research and standard development to the commercialization stage of the entire industry chain. By introducing OSU capabilities through lossless upgrades of network devices, existing network investments can be maximally protected and the threshold for OSU introduction can be lowered. China Telecom will continue to innovate, lead the development of technology and standards in the M-OTN/OSU industry, collaborate with upstream and downstream parties in the industry chain to create a complete ecosystem, actively promote the scale deployment and application of M-OTN/OSU, enrich the network dedicated line service capabilities, enhance the business carrying capacity of OTN networks, and meet the requirements of different dedicated line users.
Reprint: http://www.cww.net.cn/article?id=580553