Wednesday, August 30, 2017

400G CFP8 PAM4 & 400GBASE-SR16 NRZ Transceiver Modules

With the price of 100G QSFP28 optics and CFP form factors (CFP module/CFP2/CFP4) dropping down in 2017, 100G technology is becoming more and more popular among data center managers and IT pros in order to cope with the ever-lasting bandwidth needs. However, 100G is not the finish line. CFP multimode source agreement (MSA) demonstrated CFP8 (16X 25 Gb/s) form factor for 400 Gigabit Ethernet at OFC 2017. Although CFP8 module is still in development, it is assured to be popular in the near future. Therefore, this article will have a clearer introduction to 400G CFP8 PAM4 and NRZ modules, and compare with the former CFP modules and 400G CDFP.
100G CFP to 400G CFP8
Introduction to 400GbE CFP8 Modules
CFP8 module is the latest developing CFP from factor version, which supports eight times and four times the bandwidth density of CFP and CFP2 form factors, respectively. The CFP8 interface supports up to 16 different lanes in each direction with nominal signaling rates of 25Gb/s or 26Gb/s per lane, and either NRZ or PAM4 signaling. As the above image shows, CFP8 is approximately the size of a CFP2 optics. This interface has been generally specified to allow for 16 x 25 Gb/s and 8 x 50 Gb/s mode.
CFP8 functional diagram
Example IEEE specifications supported by CFP8:
  • 400GBASE-SR16 parallel MMF (16x25G NRZ)
  • 400GBASE-FR8/LR8 duplex SMF (8x50G PAM4 WDM)
  • 400GBASE-DR4 parallel SMF (4x100G PAM4)
  • CDAUI-16, CDAUI-8
400G CFP8 FR8 and LR8 Transceivers with PAM4 Technology
CFP8 PAM4 optics, compliant with IEEE 802.3bs 400GBASE-FR8 & LR8 electrical interface specifications, offers higher receiver bandwidth capacity for reach up to 2km and 10km. The 400GBASE-FR8 & LR8 consumes less than half the power per GB compared to a 100G CFP4 msa solution. CFP8 optics uses LC duplex fiber cables.
PAM4 and NRZ
The PAM4 stands for pulse amplitude modulation with four levels. Instead of driving the laser to generate one of the two output amplitudes, like NRZ, PAM4 technology generates four different amplitude levels, meaning a network based on PAM-4 can send twice as much data as an NRZ version.
CFP8 400GBASE-SR16 with NRZ Technology
CFP8 400GBASE-SR16 modules focus on non-return to zero (NRZ) signal modulation Scheme. To use an analogy, it means you’re sending signals in the most simple format: “light on” and “light off.” A ‘1” is transmitted as pulse of light whereas ‘0” is no light output. Based on the currently available fast VCSEL light sources only achieving data rates of 25G, sixteen channels must transmit in parallel to create a 400G data stream.
Due to the design simplicity NRZ, the modulation format of choice for all data rates up to 25Gb/s. 400GBASE-SR16 CFP8 transceivers requires 16 fiber pairs to support a total of 400Gb/s with MPO multimode cables.
What’s New With CFP8 Module?
A CFP8 module is a hot pluggable module. Compared with the former modules, the control and status reporting functions between a host and a CFP8 module use non-data control and status reporting pins on the 124-pin connector. There are three Hardware Control pins, two Hardware Alarm pins, and four pins dedicated to the MDIO interface.
Compared to CFP2/CFP4 MSA Optics
CFP8 is the proposed CFP8 from factor by MSA member companies. It maintains the large size of CFP form factor (nearly the size of CFP2, larger than CFP4 MSA modules), but supports 4x100G i.e. 4x the CFP2. Besides this, CFP8 uses less power than the former CFP form factor modules. There are 400GBASE-SR16 for parallel MMF 16x25G NRZ, and 400GBase-FR8/LR8 duplex SMF 8x50G PAM4 WDM.
CFP8 is not the first released 16x25G= 400G modules, but CDFP. 400G CDFP module (CD=400 in Latin), is the four generation CFP form factor. Providing a high level of integration, performance and long-term reliability, the CDFP 400 Gbps interface is available in short- and long-body versions. The specifications are compatible for use with direct attach cables, active optical cables, and connectorized optical modules. The CDFP module will support:
  • 5 meter direct attach cables
  • 100 meter multimode fiber
  • 500 meter parallel single‐mode fiber
  • 2 kilometers of duplex single‐mode fiber
The compact modules are well suited for low power applications using copper, VCSEL or silicon photonics based technology. They also targeted InfiniBand EDR hydra cables and 128GFC applications but so far little market segment pick up. Though relatively new with 2014 and 2015 rev releases, CDFP may be short lived due to the smaller more efficient developing set of CFP8 solutions.
Latest Trend With 400 Gb/s in the Industry
While 400 GbE standard is still a few years away, the need for 400 Gb/s interfaces is here today. The CDFP form factor is already being used in proprietary interfaces to interconnect high performance servers and will soon be used to interconnect switch and router chassis. 400G CFP8 FR8/LR8 PAM4 and 400GBASE-SR16 modules had been displayed at OFC 2017. Finisar, Fujitsu, and oclaro, etc MSA member enterprises will introduce low profile 400G modules in a short period.
These proprietary chassis interconnects have always been massively parallel and will continue because they provide the massive bandwidth needed to interconnect equipment so that multiple chassis perform as one big chassis. While 16 lanes is a fairly wide interface, multiple applications need the maximum amount of bandwidth that can only be provided by many parallel lanes running at the fastest speed available. It seem that CFP8 with the same 16 MPO connectors has much potential than CDFP modules. FS.COM offers a large stock MSA-compliant optical transceivers, including 100G CFP/CFP2/CFP4 MSA, CXP, and QSFP28 transceiver modules. We will keep in path with the informative world, and provide the best services & telecom products to all of our customers.

Wednesday, August 16, 2017

100G CFP Transceiver – Ultra High Speed Transmission Solution

During the past few years, 40G technology has dominated telecommunications. But now, with the introduction of the 100G technology, everyone is talking about 100 Gbps as the next generation. Whether willing or not, IT managers and data center designers have to consider migrate their network to 100 Gbps in the near future. And CFP is designed to fulfil the deployment of 100G network for companies and enterprises.
Brief Introduction to 100G CFP Optics
CFP transceiver was designed after SFP transceiver interface, but it supports much larger internet speed, which is realized by using 10×10Gbit/s in each direction (RX, TX). Here the C stands for 100 in Roman numerals (centum). We can infer from the name that CFP is introduced to serve as optical transceiver for 100G interfaces. Since the electrical connection of the CFP uses 10×10Gbit/s lanes in every direction, the optical connection can support both 10×10Gbit/s and 4×25Gbit/s variants of 100Gbit/s interconnects (typically known as 100GBASE-LR10 and 100GBASE-LR4 in 10km SMF reach, and 100GBASE-ER10 and 100GBASE-ER4 in 40km SMF reach, and 100GBASE-SR10 in 100 meter MMF reach respectively.)
100G CFP optics
Different Types of 100G CFP
There are several CFP types to be introduced—CFP, CFP2 and CFP4. CFP2 and CFP4 are the upgraded generation of CFP. Among them, the size of CFP is the largest. CFP2 is half the size of CFP while CFP4 is the half size of CFP2. And the features of the three different types have been summarized in the following texts. One thing that needs to be noted is that although they are not interchangeable, but could be interoperable at the optical interface with appropriate connectors.
100G CFP
Features and Benefits of CFP:
  • Supports 40G and 100G Ethernet CFP optical transceivers
  • Capable of side by side mounting as well as “belly to belly” mounting
  • Provides full EMI shielding
  • Uses a universal rail for both left and right positions
  • Allows integration of host PCB to host bezel (face plate) by either of two methods for manufacturing flexibility.
Features and Benefits of CFP2 and CFP4:
  • Up to 28 Gbps per lane – 2.8 times faster than current CFP products
  • High density, 0.6mm contact pitch
  • Provides one of the industry’s leading Signal Integrity (SI) performance for 28 Gbps per lane
  • Features a ruggedized cage construction for a more robust solution to help mitigate cage warping
  • Flexible design options to address your needs including ganged cages, heat sinks, single-sided and belly-to-belly mounting styles, light-pipes, and the capability to support mid- to long-reach applications
FS 100G CFP Solution
As one of the leading providers in optical communication , FS provides customers with transceivers that are manufactured at the highest quality of standards in the industry. All the CFP transceivers mentioned above, including both CFP2 and CFP4, are available in our website. And every transceiver is individually tested on corresponding equipment such as Cisco, Arista, Juniper, Dell, Brocade and other brands, and passed the monitoring of our intelligent quality control system. Also, all the products in FS are fully warranted against defects in material and workmanship with a lifetime guarantee.
2017 has witnessed the prosperity of the telecommunication market. Many research company predicts that the market of 2018 for telecommunication field will continue to thrive. With such a bright future, fiber optics market attracts a wide attention and many vendors want a piece of the pie. At present, 40G is ubiquitous in the data center and 100G is accelerating. As for the optical transceiver, it has been developed in the past decades to adapt to the high-speed requirement from 1G to 40G even to 100G. Believe it or not, 100G is on the way. Don’t wait to get fully prepared for the upcoming 100G era with CFP transceivers.

Thursday, August 3, 2017

OM5 Fiber Cable – Is It Worthwhile for 40G/100G SWDM4 Cabling Solution

OM5 multimode fiber, as the advanced version of the old OM4 fiber, is thought to be the future of multimode cabling. It is the Wideband multimode fiber (WBMMF) that can support wavelengths between 850nm and 953nm. It is also designed to support the short wavelength division multiplexing (SWDM)—one of the new technology for 40G/100G connection. However, will it be the ideal transmission medium for 40GbE/100GbE cabling solution?
How OM5 Fiber Developed
Over the past thirty years, multimode fiber has been evolved from OM1 to OM5 multimode fiber. OM1 and OM2 fiber, released at the end of 20th century, are the legacy 125µm multimode fiber that are working fine in 10Mb/s, 100Mb/s and 1000Mb/s cabling solution. However, with the high speed data rate like 10Gb/s, 40Gb/s, 100Gb/s and beyond coming into our life, multimode cabling (OM1 and OM2 ) with LEDs can not meet the requirement. The laser-optimized OM3 and OM4 has been developed subsequently. OM4 fiber cable, with the internal construction, possess higher modal bandwidth than OM3 fiber, which is commonly used fiber medium for 40G/100G connection.
OM1-OM5 fiber
But there is a problem. In a 40G layout, fiber optic technicians have to use one MTP fiber and 4 OM4 duplex fibers (total 8 fibers), which is obvious not preferable for high-density cabling networks. So here comes the OM5 fiber. By utilizing SWDM technology, it can greatly reduce fiber count into 2 fibers (4×10G) in 40G networks, 2 fibers (4×25G) in 100G links. OM5 is the lime green multimode fiber, displayed as follows.
OM5 Fiber
OM5 Fiber for 40G/100G SWDM4 Cabling Solution
Reduce fiber count for 40G/100G connection—OM5 fiber as the advanced version of OM3/OM4 fiber, is backward compatible with OM3 and OM4 fiber cabling. And with the SWDM technology, this fiber can only use two OM5 fibers and 40/100G SWDM4 transceivers in 40G and 100G SWDM4 cabling.
Longer-transmission distance—OM5 is designed and specified to support at least four WDM channels at a minimum speed of 28Gbps per channel through the 850-953 window. Compared to OM4 fiber cable, it is specified only to work at the 850 nm window. OM5 multimode fiber delivers higher value to network owners for distances up to 440m (for data rates up to 40Gbps), and allows for smooth migration to 400Gbps for distances up to 150m. While OM4 fiber cover the distance of 350m, 100m over 40G/100G respectively.
Easy management & installation—in 40G/100G network, multimode connectivity together with MTP/MPO systems makes for a more user-friendly solution for data centers as well as building and campus backbones, especially in cable installation, troubleshooting, cleaning, and overall maintenance.
FS OM5 Cable Solution
FS offer Lime green OM5 fibers. All our OM5 fiber cables are guaranteed by End Face Geometry Test, Continuity Test, and 3D interferometry Test to be high quality. Available in LC, SC, FC, ST, etc. Connectors, and the cable length of OM5 fiber can be provided from less than 1 meter to more than 100 meters, which will well meet the needs for 400m transmission of 40G SWDM4 QSFP+ module and 100m transmission of 100G SWDM4 QSFP28 module, as well as the links on the same rack or row.
fiber optic cable
Not only the OM1/OM2/OM3/OM4/OM5 multimode fibers are provided at FS.COM, but fiber optic cables like singlemode fibers (OS1/OS2) , Twinax copper cables are also offered. For more information about the cost-effective fiber patch cables, Please feel free to contact us via