What You Should Know About 40G QSFP+ BIDI Transceiver?

Whether in Ethernet network, data center or in IT infrastructure, the demand for higher transmit data rate, larger capacity, wider bandwidth and superior performance will never slow down. As nowadays more and more devices and data are accessed to Ethernet such as cloud computing, super computer, IDC, enterprise server room and your handy mobile phone, which may explain why so many device and service providers consider migrating from 10G to 40G is such a advisable movement. By following the trend, this article will have brief introduction for 40G QSFP+ BIDI transceiver, which enables an optimized network solution to implement 40Gbp/s data rate.
Introduction of 40G QSFP+ BIDI Transceiver
BIDI transceiver known as bidirectional transceiver, which is operating over two different wavelengths to transmit in both directions over just one fiber. To distinguish, BIDI transceiver has one connecting port only while there are two ports in ordinary optical transceiver. Why the signal of different center wavelength can be transmitted and received in both directions within BIDI transceiver? That is important to know WDM technology i.e. wavelength division multiplexing, the wavelengths like 1310nm/1550nm, 1310nm/1490nm, 1510nm/1590nm are mostly popular adopted in BIDI optical module.
40G QSFP+ BIDI transceiver, by it’s two 20G signal channels, each channel can transmit and receive two wavelengths synchronously over one strand MMF(Multi Mode Fiber) with a transmitted distance of up to 100m by OM3 and 150m by OM4. Moreover, it can deploy and re-assemble the current 10G cabling system to adapted to 40G network connection. That is to say, by making use of 10G cable plant you can obtain a 40G speeds of date rate without employ any other devices.
Operational Principle
Different from ordinary 40G optical transceiver, 40G QSFP+ BIDI transceiver has critical electron component of WDM couplers, which is functional to combine and separate data over one fiber based on the wavelengths of the light. The processing of two directions on one fiber is happened at the both ends of MMF with duplex LC connector which is showing as below :
Features of 40G QSFP+ BIDI Transceiver
40G QSFP+ transceiver plus BIDI technology is a very high-performance transceiver, which is quite in need to servers and end users that require the connectivity of 40G Ethernet.
Much more Cost-effective by less fiber cables and patch panels compared to counterpart transceivers with a limited transmit length of up to150m, meanwhile save space in data centers.
Compliantwith the QSFP+ MSA specification, enabling customers to use it on all QSFP+ 40-Gbps platforms to achieve high-density 40 Gigabit Ethernet networks.
Offers customers a compelling solution that enables reuse of their existing 10 gigabit duplex MMF infrastructure for migration to 40 Gigabit Ethernet connectivity.
40G QSFP+ BIDI vs. 40G QSFP+ SR4 Transceiver
40G QSFP+ SR4 transceiver delivers signal over four independent full-duplex channels by utilizing MPO/MTP Connector and MMF. Same length with 40G QSFP+ BIDI, available reach of up to 100m over OM3 optical fiber jumper and 150m over OM4 jumper.
Even with the same distance, 40G QSFP+ BIDI transceiver removes 40G cabling cost barriers in data center networks. It provides immense savings and simplicity compared to 40G QSFP+ SR4. The main differences between the two kinds of transceiver are connections and structured cabling, see below figures for further comparison:
Conclusion
40G QSFP+ BIDI transceiver is a perfect solution in scenario like data centers where require short-reach, limited fibers and saved operation space of 40G connectivity. And the deployment of 40G BIDI transceiver can increasingly expand the existing bandwidth capacity and help to promote economical and superior performance of optical network.

What is cable blowing? How it works?

With the rapid development of modern science and technology, optical communication technology in all aspects of life have been applied, which makes it received more and more attention. Optical cables, as the carrier of data transmission for optical communication, the proper laying of optical cable is a good guarantee for the dissemination of information data. For a long time, the most common way to lay the cable is to lay the cable directly into the underground, which has been widely promoted and applied.
Another way is embedding ducts. Put pipes through the ducts when necessary. Later, the cables should be inserted into the duct by pull, that is, drag them into ducts.
By the fear of force of friction may easy to cause break or deckle-edged of fiber cables, lubricant/oil is pre-applied on the ducts. However, the lubricant will accumulated on the bottom of due to gravity.
Later, scientists found a new way to laying cable by changing a thinking, laying air-blowing cables. Sometimes called “cable blowing ” , these methods use a high-volume air flow (7 bar back pressure) to “push” the cable. Most blowing machines also have mechanical “pushing”, where the cable is pushed by traction rollers as it enters the duct.
What is the advantages? The outside duct is of PVC, inner pipe is on silicone. Silicone pipe is soft, flexible, but it’s not liquid, won’t slide to be piled. Fibers will be blown in when necessary.
That is cable blowing. It’s more gentle to laying cables compared the ways applied before.
NKF company from Netherlands invented a new execution methods for cable blowing. They use a PVC duct with diameter of 40mm, which allows a number of cables blown in, so project can be staged construction according to business needs and capital situation. Currently, NKF company has successfully applied this new construction method to the cable trunk project from San Diego to Phoenix, the west coast of USA. The project is about 650km totally, the final design of the cable size is 288 cores(5pcs multiply 60 cores fiber cables), divided to 5 constructions. Initially, they only blew one 60 core cable and 5 pipes. In the following days, blow other cables to the rest deserved pipes according to demands. As the plan, the rest construction will be completed in the following 10 years in 4 different times. This will not only meet the current fiber needs, but also save the initial investment costs, warmly welcome by the operating company.
The key features of the cable blowing:
Protect the cables’ performance better: compared with other cable laying methods, the tension of cable during the laying process is relatively even and much smaller;
The laying process is simplified, it’s faster and more cost-effective to laying cables;
The length of one single laying is much longer: you can adopt longer fiber optic cable to reduce the number of joints and diminish the attenuation;
The number of manholes and hand holes on the pipeline lines can be greatly reduced;
Labors for laying execution is reduced.

How to Locate Fiber Problem in One Second?

Fiber Visual Fault Locator is a kind of device which is able to locate visual faults including tight bends, breaks and bad connectors immediately. You can diagnose and repair simple fiber optic link problems with the help of Fiber Optic Visual Fault Locator. This laser-powered VFL enables you to locate fibers, verify continuity and polarity, and helps you find the location of breaks in fiber optic cables, connectors and splices.
The Visual Fault Locator, model BWJ650-10, can be operated in continuous or flashing modes for easier identification. This fiber optic VFL is compatible with 2.5mm and 1.25mm fiber optic connectors(with optional adapter, watch video below), providing you with easy connectivity. You will find that this ruggedly constructed fiber optic Visual Fault Locator stands up to the demands of field-testing. This fiber optic testing device is housed in an ergonomic case that survives drops, impacts and vibrations The fiber optic Visual Fault Locator also features long battery life for hours of use. BWJ650-10 can locate fault up to 10km in fiber cable(BWJ650-20, up to 20km), with compact in size, light in weight, red laser output.
Specifications
Product: Fiber Visual Fault Locator BWJ650-10
Wavelength: 650 ± 10nm
Output Frequency: 10mWDetect
Operating Temperature: 0~60°C
Features
Accelerates end-to-end fiber continuity checks;
Speeds fiber tracing and identification;
Aids in location of fiber faults, tight bends, breaks and bad connectors;
Connects to 2.5mm standard connectors;
Connects to 1.25mm LC connectors (with optional adapter).

How to choose 40G QSFP+? AOC, DAC or Transceiver?

40Gbps QSFP+ ports are very popular in IDC. Then, do you know how to choose the most suitable product for your networking infrastructure? It refers to the link length, fiber applied, devices to be connected etc.
For 1~5m link length, 40G QSFP+ DAC is the ideal choice for data center. QSFP+ DAC owns advantages:
Lower Power Consumption: as DAC cables all are passive direct-attach copper cables, no power consumption;
Wider Temperature Range: this is also because it’s passive design;
Lower Cost: could save about 60% or more compared with QSFP+ AOC cable. As data center applied DACs in large quantity, so there will be a large amount to be save;
Faster Transmission: as it is no need to switch between optical to electronic signals.
It is easy to realize the connectivity between two 40G switches or connect one 40G and 10G switches by QSFP+ breakout cables(QSFP-4SFP10G-CU1M).
For 1~100m link length, 40G QSFP+ AOC is preferable for data center. QSFP+ AOC is consist of two QSFP+ transceivers and one 8-core fiber cable, with laser components inside, cable and connector are fixed, which meets the data centers’ usage habit, needless to consider the plug in or plug out of patch cords.
The cables of AOC are thin and AOC has better bend radius than DAC, so if the data centers don’t have enough space for cabling, AOC is a good choice.
Also because the AOC cable is thin and space-saved, the switches will have more room for air flow and easy for cooling system.
AOC always has a good eye pattern, and its performance is very good. It can meet up to 100m on OM3 MMF or up to 150m on OM4 MMF.
Once it’s short distance connection of 1m~150m, you could adopt 40G QSFP+ SR4 optic. It offers 4 independent signal channels each capable of 10Gbps, over 100 meters on OM3 or over 150 meters on OM4.
As a transceiver, it always supports DD function. Enterprise network always uses this solution.
When the link length is less than 300m, 40G QSFP+ eSR4 module is suggested to use. QSFP+ eSR4 supports link lengths of up to 300 meters and 400 meters on laser-optimized OM3 and OM4 MMF respectively.
If your link length is long about 2km, please use 40G QSFP+ IR4 transceiver. 40G QSFP+ IR4 module supports link lengths of up to 2 kilometers over a standard pair of G.652 single-mode fiber (SMF) with duplex LC connectors.
For long distance connection of 10km, the 40GBASE-LR4 QSFP module supports link lengths of up to 10 kilometers over a standard pair of G.652 single-mode fiber with duplex LC connectors. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device. This is applied when you connect two 40Gb devices.
If you would like to connect a 40G switch and a 10G switch away from each other 10km, 40G QSFP+ LR4 PSM module is the solution, which is available to link with 4x 10G devices on MPO to 8LC patch cord cables(SMF), as solution picture below.
40G QSFP+ LX4 transceiver is a hot star, as it can work with MMF or SMF. It’s role has been a very good play especially when used in lines that do not know what cable used. When QSFP+ LX4 module works with OM3, it supports up to 150m on OM3. When QSFP+ LX4 module connects with SMF, it supports up to 2km.
Conclusion
Finally, which brand should we choose for the 40G QSFP+ AOC, DAC and transceivers? Cisco, H3C, Juniper etc. are the most common brands, however products of these brands can only be applied in the corresponding switches. And the price of original pieces are super high, that caused there are renewed, recycled and even fake products in market. Here I recommend you two companies: Finisar and fiber-mart, which are the leading optical communication products manufacturers. fiber-mart‘s products can be coded according to the switch model. They can satisfy most of the switches in the current market.

Summary of 40Gb QSFP+ Transceivers

If you’re looking for versatility in your transceivers, look no further than fiber-mart’s line of 40G QSFP+ transceivers. Perfect for multi-lane data communication, interconnecting applications, datacom switches, data aggregation and many more applications, the 40G QSFP+ can meet the demands of your data center. There are many options and variety to choose from to fit your demands. Let’s take a look at the options available from fiber-mart.
Like all QSFP+ modules, the QSFP+ SR & eSR are designed to support SCSI, InfiniBand SDR DDR & QDR, 40G Ethernet, TOR Switch and other communications standards. This short range transceiver, 100m and 300m for the SR4 and eSR4 respectively, uses MPO/MMF interface and 850nm lasers. The short distance is perfect for most data center applications and usages particularly in connecting Ethernet switches to 12 lane OM3/OM4 cables. This allows for high bandwidth optical links with multi-fiber connectors (MTP/MPO). The other advantage of the SR4 is the low power consumption at less than 1.5w. fiber-mart tests and certifies every transceiver to make sure it’s fully compatible with your system. This is the perfect choice for your inter-data center needs.
While the SR4 & eSR4 provide high quality, short-range performance, the LR4 & ER4 are designed for longer range applications. Also different from the SR4s, the LR4s run on LC Duplex or SMF interfaces. Combining two strands of fiber and four CWDM wavelengths, the cable delivers data at a rate of 10Gbit/s per wavelength. This allows them to not sacrifice performance for length. The ranges vary with the 2km LR4 Lite, 10km LR4 and 30km ER4. The only difference between the ER4 and LR4 is that the ER4 uses APD RX, which is common in longer distance transceivers, instead of PIN. The LR4 & ER4 cables are perfect for data center to data center connectivity or internet exchange point sites. For your long range transceiver needs, fiber-mart always has LR4s and ER4s in-stock and ready to ship.
If you’re looking for a transceiver that provides both intermediate range and MPO/SMF connectivity, look no further than the fiber-mart QSFP+ PSM (Parallel Single Mode) IR4 and LR4. Giving the same output and performance as the standard SR4 and LR4 modules, the PSM provides the variability to split the connection into 4x10G connections. This is great for servers that want to maximize their server space and connectivity. The IR4 & LR4 models use 1310nm wavelengths and have a maximum reach of 1.4km & 10km respectively. fiber-mart makes sure that these products are compatible with all systems and networks in our state of the art testing facility.

A Simple Application of 10GBase-T Transceiver in Copper Network

Besides fiber optic cables, 10G Ethernet SFP+ transceivers can transfer data over copper cables, like twin-axial cabling or twisted pair cabling. This kind of SFP+ transceiver is equipped with a RJ-45 connector on one side, as the below figure shows. It is called 10GBase-T SFP+ transceiver. With cat6, cat6a or cat7 copper cables, 10GBase-T SFP+ transceiver could make a link length up to 30 meters.
Why SFP+ 10GBase-T transceiver?
Since optic fiber could make transmit faster and further and build a complete network system, why SFP+ 10GBase-T transceiver is needed? This is a key question encountered by 10GBase-T SFP+ transceiver. As a star member of 10G SFP+ transceiver family, 10GBase-T SFP+ transceiver is popular for a wide range of applications in copper-based infrastructure of network system. When connecting 10G modules to copper networks, 10GBase-T SFP+ transceiver can directly connect into the copper networks, while the other 10G SFP+ transceivers using optic fibers need to connect with media converter to realize this connection. Let me show you this application with a good example.
A Specific Application
Sometimes, due to the consideration of cost savings, there are some devices equipped with RJ-45 port still working in 10G Ethernet standard in many data centers, workstation, or servers network. For these devices, the only way to connect them to a host switch is using the RJ-45 port over a cat6a or cat7 copper cable. But what if this host switch has no RJ-45 port but only SFP+ slots? There are two solutions answering this question.
The first solution is using a SFP+ 10GBase-SR transceiver, a fiber patch cord with duplex LC port, a media converter and finally a cat6a copper cable connecting to the endpoint.
Like the table shown above, the second solution is very simple. Just a SFP+ 10GBase-T transceiver and a cat6, cat6a or cat7 copper cable are enough. No optical fiber and no media converter mean lower cost.
Now note the point in this application. First, you do have a endpoint with RJ-45 port. Second,  you have a host switch equipped with SFP+ slots but no RJ-45 port. Third, you don’t want to dissipate neither of them and hope put them together to build a network. Then, being the cable system within 30 meters is under application. So SFP+ 10GBase-T transceiver is a good and advisable choice.
10Gtek provides the 100% compatible SFP+ 10GBase-T transceiver with many switch vendors such as Cisco, HP, Juniper, Arista, Brocade and etc. Since it has the interoperability for a ranges of brands, 10Gtek SFP+ 10GBase-T transceiver certainly will run well in this kind of application.