Navigating through any and all options available when planning to deploy a 100G optical solution can be challenging, an alphabet soup of acronyms if you will. Customers are often left asking, “why do you optical guys/gals have to make things so complicated!?”. Customer needs drive innovation, and this has led to proliferation of form factors and reaches that give providers the tools to optimize their network build. So what 100G solution is right for you? Let’s dive in and simplify this optics alphabet soup!
“D” is for Datacenter Deployment
The QSFP28 form factor has become the form-factor of choice for datacenter deployment. “Q” because this little, pack-of-gum sized optic, integrates four transmitters and receivers each communicating at 25Gbps to achieve that 100G interface.
The workhorses of this form factor have been the SR4 (parallel multi-mode fiber up to 100m) and LR4 (duplex single mode fiber up to 10km) variants. SR4 is the lower cost option and deployed within data centers for blade to blade and rack to rack communication. LR4, a more costly solution with higher power, incorporates single mode lasers which provide the capability to communicate between data centers, campuses, in metro applications.
ER4L (‘L’ for lite) pushes this further, up to 40km or 30km, with or without Forward Error Correction (FEC) enabled on the host router, respectively.
Unfortunately, SR4 and its 100m limit often isn’t enough for the larger data centers, and the price-point for LR4 and its 10km capability can be a steep jump when a network engineer is looking for something in the 500m to 2km range. In the spirit of driving innovation based on customer needs, the industry has provided additional options to fill that gap between SR4 and LR4 with PSM4 and CWDM4, but what’s the difference?
“F” is for Filling the Gap with PSM4 and CWDM4
PSM4 (parallel single mode) uses four identical 1310nm lasers and associated receivers to interface to a parallel fiber interface in an MPO/MTP connector and provides a link of at least 500m. Unlike SR4, LR4, and ER4L, there is no internal mux/demux to consolidate all four lasers into a single fiber. This keeps the device cost lower at the expense of a more customized optical cabling solution.
CWDM4 incorporates four lasers from the CWDM bands around 1310nm and muxes them into a duplex single-mode fiber solution, similar to LR4 but at a lower cost and a defined reach of 2km. The tradeoff with PSM4 is that CWDM4 is a slightly more complex device and thus slightly costlier, but the fiber solution can be simpler. Having the option of both lets the network engineering and deployment team optimize their solution based on cabling capabilities.
“Q” is for QSFP28 SRBD in Fiber Constrained Deployments
The QSFP28 SRBD is a multi-mode bidi alternative to the SR4 and provides an additional tool for planners in tight, fiber constrained situations.
Despite the market prevalence of the QSFP28 form factor, the CFP “family” (CFP/CFP2/CFP4) is still quite relevant and commonly deployed in optical transport applications which often require both ethernet and the faster OTN data rates (eg, 112Gbps). Variance/reaches available in these form factors include:
- SR10 – 300m multimode in a parallel fiber interface
- LR4 and ER4 – 10km and 40km over single mode fiber
- CFP2 DCO – 80km coherent DWDM solution which is possible in the CFP2 form factor because of its larger package and power dissipation capabilities over the QSFP28
Integra’s CFP and CFP2 converters provide a user with the capability of deploying a QSFP28 in a CFP or CFP2 slot to take advantage of the price and availability of the QSFP28 form factor while keeping that legacy, revenue generating equipment running.
“E” is for Experts, and A Suite of Options at Your Fingertips
Having this full suite of options at your fingertips can be overwhelming, but having options is a good thing so that you can make a strong choice on a solution perfect for your deployment! It is important to work with an optical provider with this full portfolio of options, whether it’s the earliest stages of your next gen network architectural development or trying to squeeze out every last bit of revenue from your legacy network, will provide architects, planners, and operations a tailored solution and the lowest total cost of ownership.
Ready to talk to one of our optics experts about your 100G deployment needs? We are here to help find the right solution for you! Schedule time to talk with one of our experts.