A Closer Look at 40G QSFP+ SR4 Transceiver

As 40G network has been widely applied in today’s data center cabling system, 40G QSFP+ transceivers gain great popularity among data center managers. And for short data transmission distance, 40G QSFP+ SR4 transceiver is preferred. This article is going to focus on 40G QSFP+ SR4 transceiver and share several cabling solutions for 40G QSFP+ SR4 with you.

Overview of 40G QSFP+ SR4 Transceiver

40G QSFP+ SR4 transceiver is a parallel fiber optic transceiver which means it uses four fibers for transmitting and four fibers for receiving at the same time. Designed with MTP/MPO interface, 40G QSFP+ SR4 transceiver is used together with multimode fiber, such as OM3 and OM4. Working on wavelength of 850 nm, 40G QSFP+ SR4 transceiver can support 40G fiber optic transmission with the link length up to 100 meters over OM3 fiber and 150 meters over OM4 fiber. For application, 40G QSFP+ SR4 transceiver can be used for 10G to 40G and 40G to 40G connections. Here is a figure of 40G QSFP+ SR4 transceiver for you.

40G QSFP+ SR4 transceiver

10G to 40G Connection

Since 40G QSFP+ SR4 transceiver uses four independent full-duplex transmit and receiver channels, the 40G optical signal can be split into four 10G optic signals. Therefore, we can increase the fiber count at the 10G distribution end to realize 10G to 40G connection. As the following figure shows, we can use 12f MPO trunk cable and fiber enclosure. Four 10G SFP+ SR transceivers are inserted into 10G ports on one side, while one 40G QSFP+ SR4 transceiver is inserted into 40G port on the other side. Then the four 10G SFP+ SR transceivers are connected with four duplex LC patch cables which are plugged into LC ports on the front side of MPO fiber cassette inside the fiber enclosure, and the 40G QSFP+ SR4 transceiver is connected with 12f MPO trunk cable which is plugged into MTP/MPO port on the rear of MPO fiber cassette. Finally, the whole optical link is completed.

40G QSFP+ SR4 transceiver for 10G to 40G connectionA

We can also use MPO to LC fanout and MTP fiber patch enclosure which includes MTP fiber adapter panels. This cabling solution is similar to the previous one, but the difference is that the four 10G SFP+ SR transceivers are connected with MPO to LC fanout which is plugged into MTP/MPO port on the MTP fiber patch enclosure. The scenario is shown in the following figure.

40G QSFP+ SR4 transceiver for 10G to 40G connectionB

40G to 40G Connection

The following figure shows the simplest scenario for 40G to 40G connection. Two 40G QSFP+ SR4 transceivers are separately inserted into two 40G switches. Then the two 40G QSFP+ SR4 transceivers are connected by 12f MPO trunk cable.

40G QSFP+ SR4 transceiver for 40G to 40G connectionA

We can also use MTP fiber patch enclosure to achieve better cable management and higher density cabling. The scenario is shown in the following figure. With the use of MTP fiber enclosure, cable management for 40G to 40G connection could be easier. A 48-port 1U rack mount MTP fiber patch enclosure includes up to four 12-port MTP fiber adapter panels with MPO MTP fiber optical adapters on it, here is a figure for you.

40G QSFP+ SR4 transceiver for 40G to 40G connectionB

Conclusion

Designed with parallel transmission mode, 40G QSFP+ SR4 transceiver has a wide range of cabling applications with great flexibility. The cabling solutions mentioned above are just several commonly used ones. As for detailed cabling solutions for 40QSFP+ SR4 transceiver, it is suggested to depend on the practical applications and cabling environments. I hope after reading this article, you can learn more about 40G QSFP+ SR4 transceiver.

Decoding Outer Jacket of MTP/MPO Cable

As high density cabling system has been widely deployed, MTP/MPO cable can be easily found in network deployment. But when you buy MTP/MPO cable in the online store, you must have been encountered with the situation where you not only have to select single-mode or multimode, 12 fibers or 24 fibers, but also have to consider the outer jacket of the cable which can protect the cable from damage. According to different cabling environment, there are different types of outer jackets, among which CMP, LSZH, CMR, CM are mostly used. How much do you know about them? This article will decode outer jacket of MTP/MPO cable and I hope it will be helpful for you when buying MTP/MPO cable.

MPO cabling

CMP

CMP (plenum-rated) cable complies the IEC (International Electrotechnical Commission) 60332-1 flammability standard. It has passed stringent burn testing and is suitable for installation into air plenum spaces, where environmental air is transported. Typical plenum spaces are between the structural ceiling and the drop ceiling or under a raised floor. CMP cable is designed to restrict flame propagation no more than five feet as well as limit the amount of smoke emitted during the fire. In spite of this, for safety reason, any high-voltage equipment is not allowed in plenum space because the fresh air can greatly increase the danger of rapid flame spreading if the equipment is on fire. Because it has high fire-retardant, it usually costs more than other types.

LSZH

The LSZH (low smoke zero halogen, also refers to LSOH or LS0H or LSFH or OHLS) has no exact IEC code equivalent. The LSZH cable is based on the compliance of IEC 60754 and IEC 61034. It is the newest in a family of ratings and it is sometimes refereed to as low toxicity cable. Containing no halogen type compounds that forms these toxic substances, LSZH cable gives of very little smoke and does not produce a dangerous gas/acid combination when exposed to flame. LSZH cable is suitable to be used in place where air circulation is poor such as aircraft, rail cars or ships. However, it is less fire-retardant than CMP.

CMR And CM

CMR (riser-rated) complies IEC 60332-3 standards. CMR cable is designed to prevent fires from spreading floor to floor in vertical installations. It can be used when cables need to be run between floors through risers or vertical shafts. CM (in-wall rated) cable is a general purpose type, which is used in cases where the fire code does not place any restrictions on cable type. Some examples are home or office environments for CPU to monitor connections.

Conclusion

To select a suitable MTP/MPO cable for your network deployment, it is necessary to learn about the relevant details of cable ratings, which is as important as other factors. As a professional MTP patch cable supplier, FS.COM provides high quality plenum and LSZH MTP/MPO patch cord at affordable prices. If you want to know more details, you can visit our site.

Applications of Serial Transmission and Parallel Transmission in Network

In the age of the Internet, we are not unfamiliar with data communication, which refers to the process of transferring data signals between two or more devices. Basically, there are two methods used to transmit data signals: serial transmission and parallel transmission. To put it simply, serial transmission sends data bits one after another over a single channel, while parallel transmission sends multiple data bits at the same time over multiple channels. Both of them are commonly used in network applications and this article will focus on applications of serial transmission and parallel transmission in network.

serial transmission and parallel transmission

Application of Serial Transmission

As in serial transmission, bits are sent sequentially on the same channel (wire), one bit at a time, the cost for wires is low but the speed of transmission is slow. In 10G network, serial transmission is usually utilized. For example, a duplex LC fiber that consists of one fiber for transmitting 10G data signals and one fiber for receiving 10G data signals is typically used to completer the data link. In high-density network applications, it is easy to find LC duplex patch cables deployed to connect different network devices.

serial transmission for 10G network

Application of Parallel Transmission

In parallel transmission, multiple bits (usually 8 bits or a byte/character) are sent on different channels (wires, channels) simultaneously over the same cable. Compared with serial transmission, parallel transmission has a faster bit rate, and the higher cost since multiple wires cost more than one single wire. Parallel transmission is usually used in 40G and 100G network because it can transfer more data signals and achieve higher speeds. For example, MTP trunk cable, terminated with MTP/MPO fiber connector on each end, can be used to achieve the connectivity. In 40G networking applications, a 12-fiber MTP fiber connector is used: 10G is sent along each channel or fiber strand in a transmit and receive direction, and 8 of the 12 fibers are used to provide 40G parallel transmission; in 100G network applications, a 24-fiber MTP fiber connector is used: 10G is sent along each channel or fiber strand in a transmit and receive direction, and 20 of the 24 fibers are used to provide 100G parallel transmission.

parallel transmission for 40G network

Note: Parallel transmission can also be applied to 25G duplex fiber pairs to reach even higher speeds or reduce the number of fibers required at a given speed. For instance, a 100G channel would require four 25G duplex fiber pairs instead of ten 10G duplex fiber pairs.

Conclusion

In network applications, serial transmission is often used in 10G connectivity, while for 40G and 100G connectivity, parallel transmission is preferred. Hope you could acquire some useful information from the article, and have a better understanding of these two data transmission methods. In addition, you can find fiber optic cables mentioned above in FS.COM. Some other fiber optics are also available here, such as 24-fiber MPO MTP loopback, MTP to LC breakout cable, MPO fiber patch panel and so on. If you want to know more details, please visit our site.

Focus on MTP-link

Characterized by providing ideal plug-and-play solutions for structure cabling, pre-terminated cabling system has gained great popularity among data center manager in recent years, and it is considered as the norm for data center network deployment. In this cabling system, optical link is accomplished by pre-terminated cabling assemblies, such as MTP/MPO trunk cable, MTP/MPO to LC breakout cable, MTP/MPO cassette and MTP/MPO fiber optic patch panel. It not difficult to find that all these MTP/MPO fiber optic cable assemblies are based on the structure of MTP/MPO connector. And two types of MTP/MPO connectors—12 fiber MTP connector and 24 fiber MTP connector are commonly used for 40G and 100G transmission. This article will focus on MTP-link and share share some opinions about MTP-link performance with you.

12-fiber MTP connector vs. 24-fiber MTP connector

About Space Utilization

High-density cabling makes the available space in data centers always precious. MTP/MPO fiber optic cable assemblies used in MTP-link that contributes to promoting space utilization are reputably appraised by data center managers. With massive cables being adopted in the data centers to carry out data transmission, MTP-link offers cabling solutions with much higher density and flexibility for data center upgrades.

About Insertion Loss

As well know that insertion loss is inevitable during the cabling. Generally, lower overall optical loss allows more margin for the network to operate, or in the case for some users, offers the option of more connections for patching locations. Therefore, components characterized by low insertion loss will be preferred. For both 12-fiber and 24-fiber MTP/MPO connector performance, the industry standard product rating is 0.5 dB maximum. And using low-loss ferrules, both 12 fiber MPO connector and 24 fiber MPO connector can be rated at 0.35 dB maximum. What’s more, there is no need to worry about higher fiber count will lead to higher insertion loss, because when using proper polishing techniques, 24-fiber MPO/MTP terminations can meet the same performance levels as 12-fiber MPO/MTP assemblies.

About Fiber Utilization

Both 12-fiber MPO cable and 24-fiber MPO cable can be used in 100G applications. When used in 4x25G solutions, 4 fibers of 12-fiber MPO cable will remain unused. As for 24-fiber MPO cable, it can be converted into three 8-fiber 100G channels that run over one cable, with all 24 fibers used to support data transmission. Maybe you feel confused about this, let me take an example. If you need to support twelve 100G channels with the 4x25G standard, by using 12-fiber MPO cable, you will need to install 12 connectors, or 144 fibers total, with 33% of the fiber wasted; while by using 24-fiber MPO cable supporting the same 12 channels, only 4 cables would be required, using 96 fibers total, at 100% fiber utilization.

About Network Performance

It is self-evident that MTP-link offers consistent high levels of network performance for improved network integrity, because the assemblies are factory terminated and the transmission testing is performed by the manufacturer before shipment. This will reduce the likelihood of many problems that may occur with field terminations. Also, testing and troubleshooting time can be greatly saved.

Conclusion

By using MTP components, MTP-link can provide fast installation, high density and high performance cabling for data centers. As 40G and 100G Ethernet is now a trend and hotspot for data center cabling system, MTP-link is a great option for data center managers and the network deployment will benefit a lot from this cabling solution. I hope after reading this article, you can have an in-depth understanding of MTP-link.

Comparison Between Base-8 Connectivity and Base-12 Connectivity

As 10G network no longer satisfies the increasing demand for high speed data transmission, many data center managers turn to 40G network. Base-2 connectivity, based on increments of two fibers, is a common type of fiber optical link in 10G network. However, this kind of connectivity is not suitable for 40G network which needs high-density cabling. For 40G network cabling, there are two popular solutions—Base-8 connectivity and Base-12 connectivity. How much do you know about these two cabling solutions? Is there any difference between them? After reading this article, you will find the answer.

Base-12 Connectivity

In Base-12 system, Base-12 connectivity makes use of fiber optical links based on increments of 12 fibers. And 12-fiber or 24-fiber MTP/MPO optical connector assemblies are usually used to accomplish the links, such as 12-fiber or 24-fiber MTP trunk cable. Here is a figure of 24-fiber trunk cable used in Base-12 system for you.

Base-12 system using a 24-fiber trunk cable

Base-8 Connectivity

The Base-8 system still uses the MTP/MPO fiber connector, but the links are built in increments of 8 fibers (as shown in the following figure). Thus 8-fiber trunk cable, 16-fiber trunk cable and 24-fiber trunk cable can be easily found in Base-8 system. Here is a figure of 24-fiber trunk cable used in Base-8 system for you.

Base-8 system using a 24-fiber trunk cable

Comparison Between Base-8 Connectivity and Base-12 Connectivity

Since the number twelve is obviously larger than the number eight, Base-12 connectivity does provide the benefit of connector with higher fiber density compared to Base-8, and thus a larger number of fibers can be installed more quickly when using Base-12 connectivity. However, as 8-fiber transceivers are utilized in most deployments of 40G network, the benefit of matching the fiber count in the MTP backbone connectivity with the fiber count of the transceiver tends to outweigh the density benefit of Base-12 connectivity. In addition, in Base-12 connectivity, four fibers for transmit and four fibers for receive, leaving four fibers unused per connection. This will lead to a significant and costly loss in fiber network utilization. But Base-8 connectivity can be a more cost-effective option for end-to-end MPO to MPO channels and architectures. In fact, Base-8 connectivity is not an universal solution and Base-12 connectivity in some cases may still be more cost-effective. The following part describes the relative benefits when comparing Base-8 versus Base-12 connectivity for a data center deployment.

Benefits of Base-8 Connectivity
  • Optimized for both 2-fiber and 8-fiber transceiver technologies.
  • Enables 100% fiber utilization for 8-fiber transceiver systems without the additional cost and insertion loss of Base-12 to Base-8 conversion devices.
  • Cable harnesses can easily route to all common port counts on switch line cards.
  • Only requires unpinned MTP patch cords for any connections within the link.
  • Most flexible solution for 40G, 100G and 400G transmission networks.
Benefits of Base-12 Connectivity
  • Higher fiber per connector density than Base-8 connectivity.
  • Compatible with the large installed base of existing Base-12 MTP deployments.
  • Where proprietary vendor specific 40G duplex 2-fiber transceiver technologies are deployed, existing Base-12 data center infrastructures offer higher fiber density per connector (Note: the vendor specific technologies are incompatible with each other, and with parallel optics,which may add a level of management complexity in a multi-vendor environment.)
Conclusion

Base-12 connectivity has dominated the 40G network market for years, while the Base-8 connectivity is an additional option to ensure that data centers have the most cost-effective, future-proof network available. And both of them have their own benefits. As for which one to choose, it depends on the requirements of the network deployment. I hope this article can help you have a better understanding of this two cabling solutions.

Talk About MPO Connector

As high-density cabling in data center has become a trend, network components characterized by saving space become popular among data center managers. There is a type of multi-fiber connector—MPO connector, which is now widely used around the world. MPO connector not only allows for more fiber ports per unit of rack space, but also satisfies the need of parallel optical interconnections for multi-fiber connection. This article is going to introduce the detailed information about MPO connector.

Structure of MPO Connector

Each MPO connector has a key on one side of the connector body. When the key sits on top, this is referred to as the key up position. On the contrary, when the key sits on bottom, we call it key down position. Each of the fiber holes in the connector is numbered in sequence from left to right, and we call these fiber holes as positions, or P1, P2, etc. Besides, as shown in the following figure, there is a white dot on the connector body to designate the position 1 side of the connector when it is plugged in. Generally, MPO connector is pin and socket connector, which requires a male side and a female side. From the figure below we can find that MPO male connector has pins, while MPO female connector has no pins.

MPO Connector Types

Originally designed for ribbon fiber, MPO connector is available in 12, 24, 48 and 72 fiber variants. Generally, there are two popular MPO connector types: 12 fiber MPO connector and 24 fiber MPO connector. The following part will introduce these two types of MPO connectors to you.

12 Fiber MPO Connector

In theory, the 12 fiber MPO connector can deliver 6x10G transmit fibers and 6x10G receive fibers. However, it actually only delivers 40G since the transceivers and the equipment are only capable of supporting 40G data rates. That means 33% fibers of the connector are not being used, only 8 fibers are being used at the transceiver while the other 4 fibers are just spares. From the figure below, you can have a better understanding of this.

12 fiber MPO connector

Accommodating 12 fibers, the 12 fiber MPO connector provides up to 12 times the density, thereby it can save space in the rack. It is the first connector which has enough repeatable performance to be accepted in data centers. If you build a backbone with a 12 fiber MPO connector, basically you can put any connection on the end to be future proofed, such as LC, SC, etc. Thus most of data centers choose 12 fiber MPO connector cabling in the backbone and MPO-LC harnesses cable connecting to equipment like switches and servers. Many equipment today still has LC transceiver interface, therefore the harness is required to convert from MPO in the backbone to LC at the port.

24 Fiber MPO Connector

With development of data centers, many data center managers come across the problem that the promoted 12 fiber MPO connector no longer matches the requirement of the data centers. Every equipment applied in the data center is either 40G (8 fibers) or 100G (24 fibers). 12 is not divisible by 8, but 24 is. If you combine 2×12 fiber MPO connectors in the backbone, you can connect 3×8 fiber MPO connectors with zero fiber waste at the switch. The 24 fiber MPO connector has similar performance to the 12 if not exactly the same.

24 fiber MPO connector

As shown in the above figure, the 24 fiber MPO connector has two rows of 12 fibers. And this additional row of fibers require an increase in the spring force to push all of those fibers together, actually double what you need for 12. With the same size as a 12 fiber MPO connector, the 24 fiber MPO connector has double the amount of fibers and reduces the amount of cable required at the back end because a 24 fiber cable is only marginally bigger than a 12 fiber cable. Moreover, when you can just have 1×24 fiber MPO connector converting to 3×8, there is no need to combine 2×12 fiber MPO connectors to make 3×8. The 24 fiber MPO connector can also satisfy the demand for 100G data rates over a single connector and 20 fibers are used for 100G (10x transmit and 10x receive).

Conclusion

MPO connector delivers the optical, mechanical and environmental performance that service providers need to expedite the addition of fiber capacity and to support higher data-rate services. It plays an important role in the high-density cabling solutions. I hope after reading this article, you can have in-depth understanding of MPO connector.