How to Select QSFP28 Optical Transceivers for 100GbE Network

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As we all know, QSFP28 is considered as
the mainstream form factor of 100GbE optical transceiver. There are many QSFP28
products on the market, including QSFP28 DAC, QSFP28 AOC, and QSFP28 optical
transceivers with different interfaces such as 100G SR4 / LR4 / PSM4 / CWDM4
optical transceivers. Which of the following is the best fit for your 100GbE
network in these QSFP28 optical transceivers? It depends on several factors,
the most basic being the distance you might want to reach and the type of cable
you plan to use. This article will focus on how to choose QSFP28 optical
transceivers for 100GBE network.

 

1. Rack Cabling: 1-5M

 

QSFP28 Passive DAC High Speed Cables
include the QSFP28 to QSFP28
DACs and the QSFP28 to 4x SFP28 DACs, all of which are ideal for use
within 5m. The QSFP28 DAC is an ideal solution to replace 100G optical
transceivers for 100G short-range connections. If your 100GbE network is
deployed in a 5m rack, the QSFP28 DAC passive high-speed cable is perfect for
you.

 

2. Multi-mode Fiber Cabling between the
Switches: 5-100M

 

There are two options for 100GbE
cabling that uses multimode fiber between switches. One is to use the most
suitable QSFP28 AOC active optical cable 3-20 meters. Another option is to use
a QSFP28 SR4 optical transceiver with a 12-pin MTP OM3 / OM4 fiber patch cord.
QSFP28 SR4 optical transceiver and 12-pin OM4 MTP fiber patch cord can support
100 meters of data transmission.

 

3. Single-mode Fiber Cabling between
the Switches :> 100m-2KM

 

More than 100 meters but less than 2
kilometers are often referred to as medium distances. For most large data
center operators, the 100GbE solution that is able to meet the medium-to-long
distance at low cost is their best choice. QSFP28 PSM4 optical transceiver and
QSFP28 CWDM4 / CRL4 optical transceiver are both suitable for long-distance
100G network. The PSM4 QSFP28 optical transceiver needs to be used with eight
parallel single-mode optical fibers at a transmission distance of about 500
meters. CWDM4 / CRL4 QSFP28 optical transceivers need to be used together with
single-mode fiber, the transmission distance can reach 2 km

 

4. Long-mode Single-mode Fiber: ≤ 10KM

 

For very long 100GbE networks, such as
connections between two buildings at distances of up to 10 km, the QSFP28
100GBASE-LR4 with an LC interface is the best defined by the IEEE and is
typically used with single mode fibers. But now, the price of QSFP28 LR4 light
module is still very high.

 

In Conclusion:

 

High-speed cables can only be used for
short-haul connections between racks and at a fraction of the cost of optical
transceivers, but their range of applications is limited. For most
applications, various 100G optical transceivers still have an irreplaceable
role. Gigalight supplies a variety of high-quality 100G optical transceivers,
and ensures 100% compatibility. For more details, please visit its official
website www.fiber-mart.com.