100G QSFP28

How to Choose 100G QSFP28 Application?

100G QSFP28 optical transceivers, 100G AOC & DAC are the most popular data interconnect solutions for data center 100G Ethernet within different transmission distance.

The networking has been transiting the 100G Ethernet era, which requires more and more 100G data connection solutions. Common 100G QSFP28 technology application includes QSFP28 optical transceiver modules, 100G AOC and 100G DAC.

A single 100G QSFP28 optical module cannot realize data transmission. It needs to be combined with jumpers to form 100G QSFP28 AOC or 100G QSFP28 DAC to transmit data.


Common data connection solutions for 100G Ethernet interconnection

Cabling in the rack: 1-5 meters If the 100GbE network is deployed in a 5m rack, it is recommended to use QSFP28 DAC passive high-speed cables.


Multimode optical fiber cabling between switches: 5-100m For 100GbE cabling that uses multimode optical fiber between switches, one is to use QSFP28 AOC active optical cable that is most suitable for 3-20 meters, and the other option is to use QSFP28 SR4 optical module and 12 Core MTPOM3/OM4 fiber optic patch cord.


Single-mode fiber cabling between switches: >100m-2km QSFP28 PSM4 and QSFP28 CWDM4/LR4 optical modules are the best choices for 100GbE solutions for medium and long distances.


Long-mode single-mode fiber: ≤10km 100G QSFP28 LR4 optical module with LC interface is the best choice defined by IEEE. It is usually used with single-mode fiber for a distance of up to 10 kilometers.

The Prospects of the 100G QSFP28 Ports for Data Centers

100G QSFP28 SR4

Based on the relevant analysis above, it may be easily inferred that 100G Base-SR4 enjoys a prospective market in the future, and this can be highlighted in the following aspects: first, from the perspective of the IEEE802.3 standard organization, 100G Base-SR4 is currently a standardized application, while the other three products have not yet been approved by the IEEE802.3 standard organization.


Second, SR4 can directly support 100G data center applications through MTP/MPO to LC breakout cables comprised of 8 fibers or 4 duplex channels. It has four independent channels for 100Gbps optical interconnects, and each channel is capable of 25Gbps, which can unify different interfaces in switches and cut the cost of traffic utilization.


Third, base on the comparison among the 4 typical models, the overall price of SR4 is currently one of the most cost-effective solutions. Last but not least, based on the existing 40GBase-SR4 cabling system, SR4’s cabling system can be directly upgraded to meet the demand for 100G, making it the preferred solution to the 40G data center upgrade.


100G Base-SWDM4 is potential due to its capacity to achieve regular 100G speed thanks to SWDM technology, which can reduce the number of fibers by 75%. This is manageable when it comes to simplifying the cabling system and is feasible for applications with higher density.     


Besides, SWDM technology supports longer transmission distances. The optical fiber using WBMMF is expected to reach a distance of 300 meters, which is suitable for the backbone distance requirements of most data centers.


Moreover, the cost of SWDM optical transceivers supported by the VCSEL light source Has little difference from that of the SR4. Though you may find that the price is 30-50% higher than the SR4 in the current market, it has an edge in terms of technology.


SWDM’s market share is not as large as the SR4’s during the inception of 100G. However, it is predicted that the 100G BaseSWDM application will increase exponentially in the subsequent phase. Compared with the current situation that more users pick up the SR4 for data center’s update and capacity expansion, some users from the brand-new data center would prefer the SWDM products.

100G QSFP28-PSM4
Compared with applications based on MMF, 100GBase-PSM4 transmits data over parallel single-mode optical fiber with a link distance of at least 500 meters, which can meet the requirements of 98% of the data center backbone. Unlike the expensive conventional single-mode transceivers, transceivers(both active and passive) backed by PSM4 technology are cost-competitive partly due to the lower cost of SMF than the MMF. This can be better exemplified if the average length of trunk meters exceeds 300 meters.


It is predicted that PSM4 will obtain some shares in the 100G market, especially for users of large data centers or some Internet IDCs. However, its SMF interface based on MTP/MPO is more susceptible to the environment, making its on-site maintenance more costly. In addition, the significant cost reduction in PSM4 is rarely seen. Therefore, all of these drawbacks may prevent it from the mainstream in the 100G application market.


100G Base-CWDM4 distinct itself from the other 3 types by its longer link distance, which can reach up to 2KM. It is suitable for ultra-large-scale data center backbone applications and 100G connections between the backbones of data center buildings in the data center industrial park.


However, the fact that 100G Base-CWDM4 has not been approved by the IEEE standardization organization has refrained from being the mainstream application in 100G data center; but it will be part of the niche market in the backbone application of the ultra-large-scale 100G data center.


Write a Comment