Although the 10G and 40G Ethernet network still occupy the majority of fiber market at present, it is predicted that more and more users would deploy 100G Ethernet network in the following years for higher capacity and faster transmission data rate, and the 100G cabling network would finally make the 10G and 40G cabling network obsolete. Is there any evidence to support this prediction? Why to replace 10G and 40G cabling network and how to deploy the 100G cabling network? Does this statement take the cost issue into consideration since the 100G products like QSFP28 transceiver and QSFP28 breakout cable are much more expensive than the 10G and 40G products? Let’s talk about these topics and find the most cost effective way to deploy the 100G cabling network.

With the fast development of fiber technology, the capacity and transmission data rate that the 10G and 40G networks offer gradually can’t meet our needs and the Ethernet network is still driven to satisfy the increasing requirements of faster and easier access to larger volumes of data. Under this trend, the 100G network is come up with that enables unsurpassed bandwidth but can be only available at a high price. As the 100G technology is gradually matured, the cost for 100G network deployment is reduced a lot. Hence, more and more users would like to deploy the 100G network for bigger bandwidth, even it would still cost higher than 10G and 40G network deployment.

Before designing the 100G cabling network, we should choose the most proper 100G fiber transceiver to greatly ensure the performance of the network. Since there are four common kinds of 100G fiber transceivers–CFP, CFP2, CFP4 and QSFP28 transceiver available on the market, let’s study the basic knowledge of these 100G transceivers and discuss which one is the best choice for the 100G network deployment.

CFP transceiver is the first version of 100G transceiver which is published after the establishment of certification for the first 100G standard for Ethernet networks. The letter “C” means 100G, while the letters “FP” stand for Form factor Pluggable, just like the “FP” in the word SFP. In order to support the 100G network, it features very huge size which is much larger than 40G QSFP+ transceiver. Meanwhile, most of the CFP transceivers double the power consumption per bit and are ten times more expensive for per bit increased. All these shortcomings hinder the popularity of CFP transceiver and make the CFP2 and CFP4 transceiver published successively.

The CFP2 and CFP4 transceiver has no any improvement in the aspects like density, power consumption and cost, but be only advanced in the size aspect. From the following figure, you can learn that the size of the CFP family become more and more smaller. However, due to the high power consumption and cost, using CFP family to deploy 100G network still can’t meet the network requirement. Under this condition, experts put forward the QSFP28 transceiver solution which is much smaller and more economic than CFP family.

In contrast to the CFP family, QSFP28 transceiver is a better choice that offers four 25-Gbps lanes, totally achieving the whole 100G network. With use of this kind of 100G transceiver, the 100G network can be deployed as easy as the 10G and 40G network. Moreover, it completely eliminates the costly gearbox found in CFP and CFP2, while highly increasing density and decreasing power and price per bit. Hence, among all the 100G transceivers, the QSFP28 transceiver is the first choice for deploying 100G network, which should be considered as the most economical transceiver solution.

After choosing the best 100G transceiver solution, it is also necessary to design the 100G cabling network. At present, there are basically two 100G cabling solutions. One is the direct cabling solution usually working with the QSFP28 cable, and the other is the breakout cabling solution that always uses the QSFP28 breakout cable. Considering that each solution has its own connection method and works with different fiber or copper cable, which one should be selected depends on the practical application.

As for the 100G direct cabling solution, it always uses the 100GBase-SR4 QSFP28 transceiver to finish short distance transmission, and 100GBASE-LR4 QSFP28 transceiver for long transmission. In short transmission case, the 100GBase-SR4 QSFP28 transceiver can support the 100G network through OM3 12 fiber multimode MTP cable at lengths up to 70 m, and 100 m through OM4 12 fiber multimode MTP cable. It can also work with the 100G QSFP28 to QSFP28 passive direct attach cable (DAC) for up to 5m transmission and with the 100G QSFP28 to QSFP28 active direct attach cable (AOC) for up to 10m transmission. While in the long transmission case, 100GBASE-LR4 QSFP28 transceiver enables the 100G network up to 10 km on single-mode LC patch cable. If much longer transmission distance is required, you are highly suggested to choose the 100GBASE-ER4 CFP transceiver that can transmit the 100G signal at lengths up to 40 km.

As for the breakout cabling solution, the connection method is very different from the previous one, which usually use the QSFP28 breakout cable to connect one QSFP28 transceiver on one side and four SFP28 transceivers on the opposite side. This kind of 100G cabling solution enables higher port bandwidth, density and configurability at a low cost and reduces power consumption in data centers. Besides, the QSFP28 breakout cables used for 100G breakout cabling can be simply divided into two types, QSFP28 to 4SFP28 DACs and AOCs. Both of the two kinds of QSFP28 breakout cables feature four individual 25G duplex cables to achieve 100G connections, similar to the 40G QSFP+ breakout cable that has four individual 10G duplex cables.

With the gradual mature of 100G Ethernet technology, the cost issue is not the obstacle for the popularization of 100G Ethernet network any more. If your network has a very low transmission speed and the capacity it offers can’t face your need, then you are recommendable to upgrade your network from 10G/40G to 100G, for faster and easier access to larger volumes of data. As for the transceiver used for 100G connection, the QSFP28 is the fist choice as the most cost effective solution at present. As for the 100G network cabling, the direct cabling for 100G to 100G connection and the breakout cabling for 100G to 4×25G connection are good solutions for 100G network deployment. Which one should be selected just depends on the practical application.