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.
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.
|Transmission Type||OSFP Product Description||Reach||Optical Connector||Wavelength||Optical Modulation||Protocol|
|Multimode fiber||400G OSFP SR8||up to 100m over parallel MMF||MTP/MPO-16||850nm||50G PAM4||IEEE P802.3cm;IEEE 802.3cd|
|Single-mode fiber||400G OSFP DR4||up to 500m over parallel SMF||MTP/MPO-12||1310nm||100G PAM4||IEEE 802.3bs|
|4000G OSFP XDR4/DR4+||up to 2km over parallel SMF||MTP/MPO-12||1310nm||100G PAM4||/|
|400G OSFP FR4||up to 2km over duplex SMF||LC||CWDM4 wavelength||100G PAM4||100Glambda MSA|
|400G OSFP 2FR4||up to 2km over duplex SMF||CS||CWDM4 wavelength||50G PAM4||IEEE 802.3bs|
|400G OSFP LR4||up to 10km over duplex SMF||LC||CWDM4 wavelength||100G PAM4||100Glambda MSA|
Connect a 400G OSFP SR8 transceiver with another 400G OSFP SR8 transceiver over an MPO-16 cable.
400G OSFP SR8 to 2*200G SR4 over MTP-16 to 2*MPO-8 breakout cable.
400G OSFP SR8 to 8*50G SFP via MTP-16 to 8*LC duplex breakout cable with up to 100m.
400G OSFP DR4 to 4*100G DR4 over MPO-12 to 4*LC duplex breakout cable.
400G OSFP DR4+ to 4*100G DR over MPO-12 to 4*LC duplex breakout cable.
400G OSFP FR4 to 400G OSFP FR4 over duplex LC cable.
OSFP 2FR4 can break out to 2*200G and interop with 2*200G-FR4 QSFP transceivers via 2*CS to 2*LC duplex cable.
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. Eg, 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.