Tag Archives: QSFP-40G-SR4

Which 40G QSFP+ Transceivers Can Be Used for 4x10G?

Since the overwhelming growth in data traffic, many data centers are loaded with 10G and 40G based Ethernet switches for 10G to 40G migration. 40G switches allow the configuration of 40G port to act as one port or break out into four individual ports. To get easy 10G/40G migration, we should better select 40G QSFP+ transceivers which can break out as 4x10G connectivity. Among so many versions of 40G QSFP+ transceivers including QSFP-40G-SR4, QSFP-40-CSR4, QSFP-40G-LR4, QSFP-40G-ER4, etc., which 40G QSFP+ transceiver can be used for 4x10G?

QSFP-40G-SR4/CSR4 for 4x10G

40G short distance multimode transceivers are interfaced with 12-fiber MTP/MPO, such as 40G SR4, CSR4. To know why these 40G QSFP+ modules can be used for 4x10G, let’s see how QSFP-40G-SR4 work? First, 4 electrical input signals of 10G converted into parallel optical signals are sent from the transmitter over 4 parallel fiber strands. Then the parallel optical signals are converted into parallel electrical signals by the use of a photo detector array and transmitted to the receiver over another 4 parallel fiber strands. QSFP-40G-SR4 needs 8 fibers to transmit and receive signals. QSFP-40G-SR4 transceivers are interfaced with 12-fiber MTP/MPO. Therefore, QSFP-40G-SR4 and QSFP-40G-CSR4 transceivers can be easily broken down to 4x10G connections. Each 10G signal lane of QSFP-40G-SR4 is compliant to IEEE 10GBASE-SR specifications. And this 10G/40G connection can be achieved by using an MTP-LC harness cable or MTP cable and MTP-LC breakout patch panel to connect the QSFP-40G-SR4 and four 10GBASE-SR modules.

QSFP-SR4-4x10G

Can QSFP-40G-LR4/ER4 Be Used for 4x10G?

QSFP-40G-LR4 transceivers apply CWDM (Coarse Wavelength Division Multiplexing) technology. From the transmitter side, 4 input electrical signals of 10G are converted into 4 CWDM optical signals by a driven 4-wavelength distributed feedback (DFB) laser array. Then 4 CWDM signals are multiplexed to a singlemode fiber for 40G optical signal transmission. On the receiver side, the receiver accepts 40G CWDM optical signals input and demultiplexes them into 4 individual 10G optical data streams with different wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed in the device. The 40 Gigabit Ethernet signal is carried over four wavelengths on a pair of singlemode fibers. The duplex fibers are used for bi-directional transmission. QSFP-40G-LR4 and QSFP-40G-ER4 are interfaced with duplex LC connector. Therefore, we can’t split QSFP-40G-LR4 or QSFP-40G-ER4 to 4 individual duplex SMF fibers to route them to 4 separate 10G transceivers by simple optical rerouting.

QSFP-LR4-4x10G

But if you insist to split the 40G into four 10G streams using QSFP-40G-LR4 or QSFP-40G-ER4 modules, how to achieve that connection? Then you need a simple multiplexer/demultiplexer which split the four wavelengths on duplex fibers into 4x10G signal in four different fibers. With such equipment, the QSFP-40G-LR4 or QSFP-40G-ER4 outputs can be physically broken down from one duplex fiber into four duplex fibers so that each of the wavelengths is transmitted in four different fibers (As the following figure shows).

QSFP-LR4-4x10G-cable

How About QSFP-40G-PLRL4?

From the above content, you may get an inclusion that multimode 40G QSFP+ transceivers can be directly used as 4x10G while singlemode 40G QSFP+ transceivers can’t. However, you ignore one singlemode transceiver QSFP-40G-PLRL4. This 40G QSFP+ transceiver connects with 12-fiber MTP/MPO patch cable though it’s designed for long distance transmission. Similar to QSFP-40G-SR4, QSFP-40G-PLRL4 also needs 8 fibers to transmit and receive signals. So you can easily get 10G/40G singlemode connection applying QSFP-40G-PLRL4.

Summary

Some data centers may face the issue of migration from 10G to 40G. Except the switch, you also need to know 40G QSFP+ transceivers well especially what kind of 40G QSFP+ transceivers can be used for 4x10G connectivity. In this article, you can see 40G QSFP+ transceivers with MTP/MPO interface can achieve that connection by simple optical routing. As to 40G QSFP+ transceivers with duplex LC interface, you need spare equipment for multiplexing/demultiplexing. For 40G to 4x10G solutions, you can find your desired one from FS.COM.

Related article: How to Extend 40G Connection up to 80 km?

QSFP+ to 4xSFP+ AOC and QSFP+ MTP Breakout Cable Solution

How to Select Fiber Patch Cable for 40G QSFP+ Modules?

FS.COM Cost-effective QSFP-40G-LX4 Transceiver

10Gbps data rate can’t meet the high-speed needs. So people start to develop 40Gbps solutions. As a result, a variety of 40G QSFP+ transceivers can be found in the market, like QSFP-40G-SR4, QSFP-40G-CSR4, QSFP-40GE-LR4, QSFP-40G-LX4, etc. Different transceivers offer different ways to migrate from 10G to 40G. Among these solutions, which one is the most cost-effective? The answer is QSFP-40G-LX4. This following test will tell about QSFP-40G-LX4 in details.

QSFP-40G-LX4 Introduction

Juniper networks JNP-QSFP-40GE-LX4 transceiver applies the new 40 Gigabit Ethernet technology — LX4 offered by Juniper. This transceiver module uses the same infrastructure as 10 GbE. The LX4 technology can meet all the performance criteria of today’s data center in which two multimode fiber strands and duplex LC connectors are used for 40GbE connectivity just like existing 10GbE infrastructure.

As the above mentioned, QSFP-40G-LX4 transceiver provides the ability to transmit full-duplex 40Gbps data traffic over one duplex multimode fiber cable with LC connectors. In other words, this transceiver delivers 40 Gbps over duplex OM3 or OM4. It can achieve the direct connection from 10 Gbps to 40 Gbps through LC duplex fiber cable. The QSFP-40G-LX4 has four 10Gbps channels. Each channel can transmit and receive simultaneously on four wavelengths over a multimode strand (see the following figure). Thus, the 40Gbps link can be connected by two multimode strands. QSFP-40G-LX4 connections can support the data transmission distance up to 100 meters over OM3 and 150 meters over OM4.

qsfp-lx4

QSFP+ LX4 Saving Cost

When preparing to migrate from 10G to 40G network, cost is one of the most important thing to be considered. As we know, existing 10Gbps connections commonly use MMF cables with LC connectors. While most 40Gbps connections often need eight fiber strands, each four parallel strands for transmitting and receiving respectively. Take 40G-QSFP-SR4 an example, it uses 12-fiber MPO cable. Under that condition, 10Gbps cabling infrastructure should be upgraded to migrate to 40Gbps. It will cause additional cost of new patch cables, new patch panels, and expansion of the current fiber trunk.

compatible-Juniper-JNP-QSFP-40G-LX4

However, QSFP LX4 transceiver can solve the cost issue. With QSFP-40G-LX4, it’s much easier to migrate from 10G to 40G network without considering the problem of deploying new cabling infrastructure or buying migration cassettes. Instead, it only needs to replace the 10GbE optical module with 40G-LX4. Because QSFP+ LX4 uses LC connectors. It allows the same cables to be used for direct 10 Gbps connections to direct 40 Gbps connections, resulting in zero-cost cabling migration. No additional spending on cabling will be required if QSFP+ LX4 transceivers are used for all 40 Gbps links. As a result, users realize 100 percent investment protection of their existing infrastructure and incur no additional cabling costs. This is a significant advantage when compared to the cost of reconstructing the cabling system using QSFP SR4 transceivers. If the cabling for this network is an expansion to the existing cabling system, the 40 Gbps connections can be built using MMF cables and QSFP SR4 transceivers or QSFP+ LX4 transceivers. QSFP+ LX4 can save a lot for 40 Gbps migration.

Conclusion

There are many solutions for the migration from 10G to 40G. QSFP+ LX4 technology
removes 40 Gbps cabling cost barriers for migrating from 10 to 40 Gbps in data center networks. QSFP+ LX4 transceivers provide 40 Gbps connectivity with huge cost savings and simplicity for next-generation data center 40GbE deployments. The QSFP+ LX4 transceiver allows organizations to migrate their existing 10 Gbps infrastructure to 40 Gbps at zero cost of fiber, and to expand the infrastructure with low capital investment. FS.COM provides JNP-QSFP-40G-LX4 transceivers with high quality and 100% compatibility. All of Fiberstore transceivers have gone through test-assured program before reaching customers. If you need any help, please contact us via sales@fs.com.

Cost-effective QSFP-40G-SR-BD Solution

25 Gigabit Ethernet emerges as the shinning star. It provides another solution (10G-25G-100G) migrating to 100 Gigabit Ethernet. But for those who just want to use 40G network instead of 25G at present, then they need to upgrade from 10G to 40G connections. As to the migration from 10G to 40G, this article will introduce a cost-effective solution – 40G quad small form-factor plugable (QSFP) bidirectional (BiDi) transceiver solution.

Traditional 40G Transceivers Solution

Fiber cabling infrastructure of 10G and 40G transceivers are different. 10GBASE-SR transceivers require multimode fiber (MMF) cable with LC connectors. While QSFP-40G-SR4 or CSR4 transceivers connect with MMF ribbon cable with MPO/MTP connectors. It means that 40G connectivity can’t reuse the 10G network cabling infrastructure. That causes great cost.

Except the connector type, there is another concern. 10GBASE-SR transceivers require 2 fiber strands per 10G link, while QSFP-40G-SR4 and CSR4 transceivers need 8-fiber strands (actually it’s 12 fiber strands.). That is because 40GBASE-SR4 and CSR4 transceivers use 4 parallel fiber pairs (8 fiber strands) and each pair at 10G for total 40G full duplex. In this case, 4 fiber strands are not used and wasted.

traditional-qsfp

Figure1. QSFP-40G-SR4: 12-fiber strands, only 8-fiber strands used

As a result, the connector’s change and the increased fiber density required for QSFP-40G-SR4 need a significant cable plant upgrade. That makes it expensive for pmmfeople to migrate form 10G to 40G network in their existing data centers.

40G bidi

QSFP-40G-SR-BD is a short-reach transceiver that delivers 40 Gbps over a duplex OM3 or OM4 MMF connection. This connection can reach the distance up to 100 meters over OM3 MMF and 150 meters over OM4 MMF. This 40G transceiver has two 20G channels. Each channel transmits and receives two wavelengths over a single MMF strand. So the transceiver supports connections over a LC duplex MMF cable.

bidi-qsfp

Figure2. QSFP-40G-SR-BD: duplex LC

Cost Comparison

It may be not so intuitive that QSFP-40G-SR-BD solution can save more cost than the traditional 40G transceivers. Let’s take a look at the following case of upgrading 10G to 40G network and compare the cost of two kinds of solutions.

In an unstructured cabling system, devices are connected directly with fiber cables. This direct-attachment design is suitable for short distance connection in a data center.

288 connections

Figure3. Direct 40G connections

From the figure, it shows that the QSFP-40G-SR4 uses MPO connector and QSFP-40G-SR-BD uses LC connectors. Therefore, with QSFP-40G-SR4, to realize the migration, all of the existing 10G MMF cabling infrastructure should be replaced because the connector are different. But it’s another case to QSFP BiDi transceiver. The existing 10G MMF cables can be reused to achieve the network upgrade from 10G to 40G. This doesn’t require any cost on cables.

In the table, the cable costs and savings of migration and new deployment of 288 direct connections. To migrate the existing 288 10G to 40 connections, FS.COM QSFP BiDi transceiver doesn’t need any cost on cable. Compare to QSFP-40G-SR4 , QSFP-40G-SR-BD can save the cost by 100%.

Fiber Cable Lengths (meters) 10 30 50
288 connections for QSFP-40G-SR-BD FS.COM LC MMF cables 2304 5760 9216
288 connections for QSFP-40G-SR4 FS.COM MPO cables 21024 37440 51840
Cost Savings from 10G to 40G (US $) 21024 37440 51840
Cost Savings of New 40G deployment (US $) 18720 31680 42624

For the case in which 288 new direct 40G connections are needed in addition to the existing cabling infrastructure for a data center migration, the savings can reach as much as 82% with the use of QSFP BiDi transceiver. This above costs doesn’t include that of installation. It’s not hard to imagine the installation cost of QSFP-40G-SR4 connections would be much higher.

Conclusion

QSFP-40G-SR-BD is a new breakthrough in 40G network. It helps the users to realize the migration from 10G to 40G without the need of replacing all 10G cabling infrastructure. Actually, compared with solutions of some other companies, FS.COM QSFP-40G-SR4 is already cheap. Since we devotes to serving our customers with the most cost-effective network connection solutions, we would like to introduce QSFP-40G-SR-BD.