As can be seen from the word, DCI refers to the network connection of two or more data centers. Depending on the distance and transmission capacity, engineer can use a variety of different technologies for interconnection, which is a broad concept. DCI can be built from the optical layer, using switches and routers. DCI generally refers to the interconnection of different data centers of operators, or the interconnection of enterprise-level data centers. In 2022, the demand for cloud services will explode, and the capacity, cost of data center interconnection will become several key points. Optical modules play a linking role in data centers, and we will introduce them in detail.
![What is Data Center Interconnect?]( "What is Data Center Interconnect?")
Distance
The distance of the DCI application depends on the dispersion of each data center. When they are in the same city, a link of tens of kilometers is often enough to interconnect them. If you are in two countries, or even two continental plates, this means a distance of hundreds of thousands of kilometers. The distance factor greatly affects the choice of the DCI scheme. For metropolitan area network links within 80km, sometimes there is no need to choose a high-cost coherent optical module solution, and the conventional 100G DWDM optical module solution can meet the performance requirements.
Capacity
In recent years, bandwidth requirements have exploded, and enterprise routers have been upgraded from 100Gb to 200Gb or even 400Gb. Coherent optical modules may be the only option to meet such high bandwidth requirements. It can achieve a rate of 800Gpbs on a single wavelength and expand the available spectrum from the C-band to the L-band. This allows more wavelengths to be utilized, increasing the capacity of the DCI. But the cost is also greatly increased.
Cost
To improve efficiency, data flows in data centers must be transported as cost-effectively as possible, so reducing the cost per Gbps of interconnects is a central issue. In the construction cost of the data center, the procurement cost of the optical module is the key point. Optical modules are involved in any layer of data center hardware, from the SFP+ DAC at the bottom to the 400G QSFP-DD at the top. In order to reduce the cost of optical modules while providing sufficient capacity, you should try to choose high-quality and inexpensive brands.
Role of Optic Transceiver modules in Data Center layout
Optical modules are used within and between data centers. Optical transceivers are used in data centers to transmit and receive optical or electrical signals.
For the inside of the data center, in the common leaf-spine architecture of the data center, 50G/40G optical modules are often used as a bridge from the access layer equipment to the aggregation layer equipment, and 100G/200G optical modules are often used from the aggregation layer to the core layer. The closer to the top of the architecture, the greater the data transfer capacity.
For the interconnection of small data centers in the medium and short distances, the cost of renting optical cables is inexpensive and the transmission capacity is not very large. In the long-distance large-capacity transmission, the connection between data centers often adopts DCI equipment based on the DWDM system. This type of device can provide OEO function and port aggregation function, and multiple 10G/40G/100 GbE client ports can be mapped to DWDM wavelength coherent optical modules with 200G, 400G and even 800G. The characteristics of the coherent optical module are that the dispersion tolerance is extremely high, the transmission within 2000KM does not need to consider the dispersion problem, and the band is tunable, and it can easily transmit hundreds of kilometers with EDFA, which is very suitable for metropolitan area network applications.
The higher the transmission rate, the longer the distance, and the higher the cost for optical modules. Therefore, to reduce the cost, we should select the optical module according to the needs such as data rate or distance, otherwise the cost will be significantly increased.
Summary
You can get all of the above optical modules for data center interconnection at bhcom.in. Bhcom is a leading optical module manufacturer, and focuses on producing and selling optic modules. If you are curious about anything related to the optical modules, please feel free to contact us. It is our pleasure to have a cooperation with you.