Complete Guide to 100G QSFP28 series
The 100G QSFP28 series include different form factors such as CFP, CFP2, CFP4, CXP and QSFP28. The CFP, C Form-factor Pluggable was the first 100G optical transceiver to be developed. The newest 100G QSFP28 technology allows to reduce considerably the cost of moving to a 100G network and thus facilitating the adoption of the 100G as a new standard for the data center market. The name of the 100G QSFP28 comes from the fact that its electrical interface can handle four channels of 25G each, potentially up to 28G. [Q stands for Quad, which means 4]. The QSFP28 has better performance and is smaller than all its C form-factor predecessors
Four different technologies can be found among the 100G QSFP28 series: Multi-mode Transceivers, Single-mode Transceivers, Direct Attached Cables and Active Optical Cables. Of course, each technology has its advantages and inconveniences. In this article, we are going to introduce each technology to help you select the most suitable 100G QSFP28 connectivity for your network.
Multi-mode transceivers are the low cost transceivers. QSFP28 SR4 use more expensive non-standard MPO connectors which cancel out some of the cost savings of the multi-mode transceiver.
100G QSFP28 SR4
The 100G QSFP28 SR4 transceiver supports connections of up to 100 meters over multi-mode fiber and uses MPO connectors. The wavelength is 850nm. The short range (SR) transceiver is the most cost effective solution to upgrade to a 100G network.
Single-Mode transceivers are more expensive than multi-mode transceivers, but they allow to reach longer distance and most of them are using standard LC connectors.
100G QSFP28 LR4
The 100G QSFP28 LR4 DFB transceiver supports connections up to 10 km over single-mode fiber and uses standard LC connectors. The wavelength is 1310nm. DFB means Distributed-Feedback laser diode
100G QSFP28 CWDM4
The 100G QSFP28 CWDM4 transceiver supports connections of up to 2km over single-mode fiber and uses standard LC connectors. The CWDM4 uses the FEC (Forward Error Transmission) technology that allows the receivers to correct the errors without needing to request re-transmission of data.
100G QSFP28 CWDM4 BIDI
The 100G QSFP28 CWDM4 BIDI transceiver supports connections up to 2km over single-mode fiber and uses LC connectors. The wavelengths are 1271nm, 1291nm, 1311nm and 1331nm.
100G QSFP28 PSM4
The 100G QSFP28 PSM4 transceiver supports connections up to 2km over single-mode fiber and uses non-standard MPO connectors. The wavelength is 1310nm.
100G QSFP28 ER4
The 100G QSFP28 ER4 transceiver supports connections up to 30 km over single-mode fiber without the FEC technology and it can reach up to 40km with the FEC technology. The QSFP28 ER4 uses standard LC connectors and its wavelength is 1310nm.
Direct Attached Cables (DAC)
Direct Attached Cables are a very common method for very short-range distance because of the their low-cost. Indeed, they are the cheapest solution for connecting 100G equipment. In addition, it is a one part product instead of the usually three part solution (two transceivers and a cable), which reduces the problems associated with dirty connectors. DAC also consume less power compared to Active Optical Cables (AOC).
There are two types of DAC, the passive copper cable for distance from 0 to 5 meters and active copper cable for distance from 5 to 15 meters.
100G QSFP28 to QSFP DAC
100G QSFP to 4 x 25G SFP28 fanout DAC
Active Optical Cables (AOC)
Active Optical Cables (AOC) are comparable to using transceivers and separated cables. They can reach longer distance than DAC, up to 100 meters. They also are lighter and smaller than DAC.
100G QSFP to QSFP AOC
100G QSFP to 4 x 25G SFP28 fanout AOC
|Technology||Standard||Optech Part Number||Features|
|Multi-Mode Transceivers||100G QSFP28 SR4||OPCW-MX1-85-CB||850nm, MPO, 100m|
|Single-Mode Transceivers||100G QSFP28 CWDM4||OPCW-S02-13-CB||1310nm, LC, 2km, FEC|
|100G QSFP28 BIDI||OPCW-W02-13-CB||1310nm, LC, 2km|
|100G QSFP28 PSM4||OPCW-S02-13-CBS||1310nm, MPO, 2km|
|100G QSFP28 LR4 DFB||OPCW-S10-13-CBD||1310nm, LC, 10km, DFB|
|100G QSFP28 ER4||OPCW-S30-13-CB||1310nm, LC, 30km, 40km (FEC)|
|Direct Attached Cables||QSFP28 to QSFP28 DAC||OPQS28-T-xx-Px||xx= 0.5 to 5m|
|QSFP28 to 4 SFP28 DAC||OPQS28-T-xx-P/SF28/4||xx= 0.5 to 5m|
|Active Optical Cables||QSFP28 to QSFP28 AOC||OPQS28-F-xx-AK||xx= 1 to 100m|
|QSFP28 to 4 SFP28 AOC||OPQS28-F-xx-A/SF28/4||xx= 1 to 100m|
Optech products are compatible with all major switches and servers brands. You can check all the compatible lists here.
Optech is a leading company in developing and manufacturing Optical Transceivers and Cables solutions for Data Center 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.
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