How to Use Optical Transceivers and Cables in Data Centers
If you are lost between the different categories of interconnects for data centers, this article is for you. A simple and clear explanation on how to use Optical Transceivers and Cables in Data Centers.
Direct Attach Cables (DAC)
A DAC is two transceivers attached together by a copper cable, creating a one part assembly. Direct Attach Cables can cover distances from 0.5 meters up to 10 meters. However they are commonly used for distance under 5 meters.
Direct Attach Cables are the perfect cost effective solution to connect devices separated by small distances. DAC are mostly used to connect switches, servers and storage inside the same rack or an adjacent rack of a data center. For distance above 5 meters it is recommended to use Active DAC to keep the strength and quality of the signal. For distance above 10 meters, the use of Active Optical Cables is preferred.
If you want to know more about Direct Attach Cables, click Here.
Active Optical Cables (AOC)
An AOC is two transceivers attached together by a optic fiber cable, creating a one part assembly. Active Optical Cables can reach distances from 3 meters up to 100 meters. However, they are commonly used for distance up to 30 meters.
Active Optical Cables are mostly used to connect switches, servers and storage between different racks a inside data center. AOCs are also used to link devices inside a same rack, but usually for distance below 3 meters, the use of DAC is preferred.
If you want to know more about Active Optical Cables, click Here.
Optical Transceivers
Compared to DAC and AOC, Optical Transceivers are not a one part assembly. Two transceivers need to be linked by a fiber cable. It exists a wide range of transceivers type, with different features (connectors, technology,..). This systems allows to reach longer distances. Transceivers can reached distances from 100 meters up to 40km. The distance of transmission depends of the data rate speed of the transceiver. For example, 30km for the 100G QSFP28 ER4 transceiver and 40km for the 40G QSFP+ ER4 transceiver.
Optical Transceivers are used in two different situations. First, to connect devices that are far away inside a data center. Second, to connect two data centers, or a data center to another infrastructure.
To know more about optical transceivers you can check our Complete Guide.
Resume
| Interconnect | Distances reached | Used |
| Direct Attach Cables (DAC) | 0,5 meter to 10 meters | to connect devices inside the same rack or an adjacent rack |
| Active Optical Cables (AOC) | 3 meters to 100 meters | to connect devices between different racks a inside data center |
| Optical Transceviers | 100 meters to 40 km | to connect devices that are faraway inside a data center.
to connect two data centers, or a data center to another infrastructure. |
About Optech
Optech is a leading company in developing and manufacturing Optical Transceivers and Cables solutions for Data Centers and Telecom market. Since 2001, Optech has been offering accurate lead time and high quality products to customers.
Optech offers a broad range of networking and communication solutions in following categories: Optical Transceivers, SFP, 10G SFP+, 25G SFP28, 40G QSFP+, 100G QSFP28, 400G QSFP-DD, Direct Attach Cables (DAC), Active Optical Cables (AOC), Ethernet Media Converter, Fiber Optical Patchcord, BWDM, CWDM, DWDM Mux/Demux and Repeater products.
For more information you can visit www.optech.com.tw or contact us at sales@optech.com.tw.
