Cloud data centers are the infrastructure of cloud computing. The continuous penetration of cloud computing services has driven the construction of cloud computing super data centers. Cloud IT infrastructure is mainly composed of switches, servers, and optical cables and optical modules (or AOCs) that interconnect all of them. The large-scale cloud data centers will greatly increase the use of optical modules, and at the same time, there are higher requirements for the transmission distance of optical modules, which will increase the proportion of single-mode optical modules.
The explosive growth of cloud data center traffic has driven the continuous upgrading of optical module working rates, and the trend is accelerating. It took 5 years for 10G rate ports to iterate to 40G rate ports, and 4 years for 40G rate ports to upgrade to 100G rate ports, and it may only take 3 years for 100G rate ports to 400G rate ports. In the future, all export data of data centers will need to undergo massive internal computing (especially with the rise of applications such as AI, the internal and export traffic will be even more amazing). Today, the flat architecture generally adopted by data centers will enable the 100G optical module market to continue to grow at a high speed.
According to a third-party report by Synergy, as of 2016, the total number of hyperscale data centers in the world exceeded 300, and in 2017 it exceeded 390. Currently, there are at least 69 hyperscale data centers in the planning or construction stage. It is predicted that by the end of 2019, the number of hyperscale data centers in the world will exceed 500. By then, 83% of public cloud servers and 86% of public cloud loads will be hosted in hyperscale data centers. The proportion of server deployment in hyperscale data centers will increase from 21% to 47%, the proportion of processing power will increase from 39% to 68%, and the proportion of traffic will increase from 34% to 53%.
Comparison between the traditional three-tier architecture and the flat two-tier architecture of the data center
Introduction to the application examples of optical modules and AOC in data center optical interconnection
The network architecture of a domestic cloud data center is divided into super core area switches (Spine Core), module core area switches (Edge Core, or Leaf Switch) and access switching area switches (TOR).
- 10G-100G AOC active optical cables are used to interconnect the server network card NIC and the access switch area switch.
- From the access switching area switch to the module core area switch, 40G-100G optical modules and MPO fiber jumpers are used for interconnection.
- From the module core switch to the super core area switch, 100G QSFP28 optical modules and LC dual-fiber fiber jumpers are used for interconnection.
Application example of optical module in a domestic cloud data center
Cloud data center port bandwidth upgrade trend (from 10G to 25G, and then to 100G)
| Deployment era | 2008–2014 | 2013–2019 | 2017–2021 | 2019– |
|---|---|---|---|---|
| Park, super large data center | 40G-LR4 | 40G-LR4 100G-CWDM4 |
100G-CWDM4 | 400G-FR4 |
| Inside the computer room | 40G-eSR4 4x10G-SR |
40G-eSR4 | 100G-SR4 | 400G-DR4 |
| Inside the rack | CAT6 | 10G AOC | 25G AOC | 100G AOC |
| Server network card speed | 1G | 10G | 25G | 100G |
Characteristics of optical module requirements in cloud data centers
Due to the differences in traffic growth rate, network architecture, reliability requirements, computer room environment and telecommunication-grade network in cloud data centers, the demand for optical modules in cloud data centers has the following characteristics: short iteration cycle, high speed requirements, high density and low power consumption.
- Short iteration cycle . The rapid growth of data center traffic has driven the continuous upgrading of optical modules, and the trend is accelerating. The generation cycle of data center hardware equipment, including optical modules, is about 3 years, while the iteration cycle of telecom-grade optical modules is generally more than 6 to 7 years.
- High speed requirements . Due to the explosive growth of data center traffic, the technical iteration of optical modules cannot keep up with the demand, and basically the most advanced technologies are applied to data centers. For higher-speed optical modules, data centers have always had a demand, and the key lies