Tag Archives: fiber optic transceiver

400G OSFP Transceiver Types Overview


OSFP stands for Octal Small Form-factor Pluggable, which consists of 8 electrical lanes, running at 50Gb/s each, for a total of the bandwidth of 400Gb/s. This post will give an introduction of 400G OSFP transceiver types, the fiber connections, and some QAs about OSFP.

400G OSFP Transceiver Types

Below lists some current main 400G OSFP transceiver types: OSFP SR8, OSFP DR4, OSFP DR4+, OSFP FR4, OSFP 2*FR4, and OSFP LR4, which summarize OSFP transceiver according to the two transmission types (over multimode fiber and single-mode fiber) they support.

Fibers Connections for 400G OSFP Transceivers


Figure 1 OSFP SR8 to OSFP SR8.jpg
  • 400G OSFP SR8 to 2× 200G SR4 over MTP-16 to 2× MPO-8 breakout cable.
Figure 2 OSFP SR8 to 2 200G SR4.jpg
  • 400G OSFP SR8 to 8× 50G SFP via MTP-16 to 8× LC duplex breakout cable with up to 100m.
Figure 3 OSFP SR8 to 8 50G SFP.jpg


  • 400G OSFP DR4 to 400G OSFP DR4 over an MTP-12/MPO-12 cable.Figure 1 OSFP SR8 to OSFP SR8.jpg
  • 400G OSFP DR4 to 4× 100G DR4 over MTP-12/MPO-12 to 4× LC duplex breakout cable.
Figure 4 OSFP DR4 to 4 100G DR.jpg


  • 400G OSFP DR4+ to 400G OSFP DR4+ over an MTP-12/MPO-12 cable.
  • 400G OSFP DR4+ to 4× 100G DR over MTP-12/MPO-12 to 4× LC duplex breakout cable.
Figure 5 OSFP DR4+ to 4 100G DR.jpg


400G OSFP FR4 to 400G OSFP FR4 over duplex LC cable.

Figure 6 OSFP FR4 to OSFP FR4.jpg

400G OSFP 2FR4

OSFP 2FR4 can break out to 2× 200G and interop with 2× 200G-FR4 QSFP transceivers via 2× CS to 2× LC duplex cable.

400G OSFP Transceivers: Q&A

Q: What does “SR8”, “DR4”, “XDR4”, “FR4”, and “LR4” mean?

A: “SR” refers to short range, and “8” implies there are 8 optical channels. “DR” refers to 500m reach using single-mode fiber, and “4” implies there are 4 optical channels. “XDR4” is short for “eXtended reach DR4”. And “LR” refers to 10km reach using single-mode fiber.

Q: Can I plug an OSFP transceiver module into a QSFP-DD port?

A: No. QSFP-DD and OSFP are totally different form factors. For more information about QSFP-DD transceivers, you can refer to 400G QSFP-DD Transceiver Types Overview. You can use only one kind of form factor in the corresponding system. E.g., if you have an OSFP system, OSFP transceivers and cables must be used.

Q: Can I plug a 100G QSFP28 module into an OSFP port?

A: Yes. A QSFP28 module can be inserted into an OSFP port but with an adapter. When using a QSFP28 module in an OSFP port, the OSFP port must be configured for a data rate of 100G instead of 400G.

Q: What other breakout options are possible apart from using OSFP modules mentioned above?

A: OSFP 400G DACs & AOCs are possible for breakout 400G connections. See 400G Direct Attach Cables (DAC & AOC) Overview for more information about 400G DACs & AOCs.

Original Source: 400G OSFP Transceiver Types Overview

Three Necessities for Smooth 40G Migration

As applications such as Big Data, Cloud and Internet of Things are brought to a variety of industries, the demand for high speed transmission is increasing rapidly ever since. Therefore, the 10GbE (Gigabit Ethernet) can no longer fulfill these requirements. So there arrives at a consensus in the industry for transmission network migration to 40/100G. The 40G severs as an excellent and economical solution to satisfy the current need for data transmission, whereas the 100G is proved to be less cost efficient and the technology of it is still immature, which makes the 100G currently beyond the reach of average companies. Nowadays, the servers are well prepared to carry the transmission of 40 Gbps in many data centers since the core technologies of 40G are advanced step by step. Besides, the cost of deploying 40G decreases as an increasing number of manufacturers are competing with each other for the 40G market. so it is high time to 40G migration.

Comparing with 1G migrating to 10G, there exists a much larger span for 10G migration to 40G with regard to transmission data rate and technologies. Thus, the deployment of 40G migration is much more complicated than that of 10G. Three factors must be taken into consideration to increase the reliability and manageability for 40G migration, which are fiber optic transceiver, transmission media, and pre-terminated MPO assemblies.

Fiber Optic Transceiver

Fiber optic interconnection plays an indispensable role in today’s telecommunication network. Photoelectric conversion pertains to a necessary part of fiber optic network. The function of fiber optic transceiver is photoelectric conversion, which makes it one of the most commonly used components in the data center. Without it, the data center cannot run normally.

QSFP-40G-LR4 transceiver

As for 40G migration, transceivers of two different package forms are commonly used: QSFP+ transceiver (Quad Small Form-factor Pluggable Plus transceiver) and CFP transceiver (C Form-factor Pluggable transceiver). QSFP+ transceiver is more popular in 40G application. A single 40G fiber optic transceiver may not be expensive. However, thousand of optical transceivers might be needed for a medium-sized data center, thus the total cost of optical transceivers can be a large sum of money. While the switch market has already been monopolized, the transceiver market is not. Third party transceivers that are compatible with various types of switches are offered in today’s market. They can perform as well as the original brand transceivers with less cost. So, many data centers begin to take compatible transceivers as one of their options. As cost serves as one essential aspect in 40G optical transceiver selection, quality also attaches more importance since not all the third party transceivers are created equal. Selecting the 40G compatible transceivers from a company that assures 100% compatibility and interoperability is necessary. The picture above shows the testing of Cisco compatible QSFP-40G-LR4 transceivers on a Cisco switch to ensure its compatibility and interoperability.

Transmission Media

40G standards of IEEE have already been announced several years ago. To meet various situations, there exists standards for different transmission media. Although fiber optic cable is becoming more and more popular, there is still a place for copper cable in the data center. Standards for both copper and fiber optic are being used. Commonly used 40G Ethernet media systems including:

  • 40GBASE-CR4: 40Gb/s Ethernet over copper cable in short transmission distance.
  • 40GBASE-SR4: 40Gb/s Ethernet over four short-range multimode fiber optic cables.
  • 40GBASE-LR4: 40Gb/s Ethernet over four wavelengths carried by a signal long-distance single-mode fiber optic cable.

Then, here comes the old question: fiber optic cable or copper cable, which one should be adopted in 40G migration? Although copper is cheaper in terms of the price, it can only support 40G transmission limited to several meters. Whereas single-mode fiber optic cable supports the 40G transmission distances up to 10km. For multimode fiber optic cables, OM3 and OM4 are supposed to support short distance transmission. The longest distance that OM3 can support for 40G transmission is 100 m, while OM4 can support a longer 40G transmission distance of 150 m. The selection of transmission media should depend on the specific applications.

pre-terminated-MTP-assemblies for 40G migration

MPO Assemblies for 40G

According to the IEEE standards, 40G multimode Ethernet transmission uses four multimode fiber optic cables. The IEEE 802.3ba standard also specifies multi-fiber push-on (MPO) connector for standard-length multimode fiber connectivity. Most of the 40G multimode Ethernet transceivers are based on the MPO technology. It is wise to increase fiber optic density by using MPO technology, but a new problem comes up. Cabling and splicing difficulties in data center increase with the accelerating number of fiber. Unlike traditional two-strand fiber connections, MPO connectors cannot be terminated easily. So, most of the data centers choose the pre-terminated MPO assemblies (as shown in the picture above) in 40G deployment, which is more reliable and can save human labor. Before cabling, it would be time-saving and cost-efficient to determine the cabling lengths and customized pre-terminated MPO assemblies with manufacturers.


During the process of migration to 40G, to select a compatible third party transceiver of high quality would contribute to decrease the money and time spending on data transmission. With the combination of specific applications and characteristics of 40G transmission media, it helps to achieve a rather economical and reliable 40G deployment task. Furthermore, pre-terminated MPO assemblies can necessarily ensure flexible and manageable cabling in 40G deployment. 40G has already become the tide of today’s data transmission and it plays a significant role in the history of network transmission.