BLOG

Finisar: New VCSEL Opportunities Possible

August, 2018

In June, this writer was honored to be a keynote speaker at EPIC’s meeting on “Singlemode vs Multimode Communication” in Kessel-Lo, Belgium. Our preliminary judgement is that we are cautiously optimistic about the prospects for Multimode Fiber (MMF) deployment growth within hyperscale data center operators. It is significantly based on the assumption that in striving to lessen latency and lower power dissipation, Microsoft’s plan to flatten its network by ultimately replacing the top-of-rack switch with a passive patch panel, and use MMF to connect the end/middle-of-row switch to a rack of wheel with servers, is adopted by all of the major hyperscale players. Obviously, such a transition would be good news to the two major, short-reach VCSEL transceiver vendors, Finisar and Foxconn Technology Group. However, given the delays that have become recently evident at the former in ramping up i ...

Read More

Co-Packaged Optics on Trial

August, 2018

Recently, fibeReality has written about the latest catchphrase in the optics space, co-packaged optics, and mentioned the potential challenges with expense and yield, as well as other alternatives. In looking at the case for the technology, it does have some attractive aspects. The tiny chip-like optical modules are superior to COBO-like gear in that the latter is lousy on pad density. The idea with the former is that the engineer is reaching inside the pluggable module, and taking out the optical engine on the tiny printed circuit board, and then throwing away a lot of the package. While the argument can be made that the package is not the most expensive part, its assembly and testing are both a part of the cost, but most importantly, the engine is only driving about two centimeters away from the switch, and so, there is a significant reduction in both the power consumption, as well as ...

Read More

Broadcom's Tomahawk 3: An Optics Riddle

August, 2018

There is a mystery concerning stranded capacity as Broadcom’s StrataXGS Tomahawk 3 next-gen switching chipset offers quite a bit of bandwidth with a total capacity of 12.8 terabytes. The problem is in imagining how it all works in that the near-term front panel pluggables cannot provide enough bandwidth on a 2-row by 16. We are assuming the use of a QSFP-DD, and even packaging two 100-gig PMDs in one QSFP, meaning 32 QSFP-DDs on that panel with 2x100G per module, working out to only 6.4 terabytes. So, a hyperscale data center operator would be short 50% in what is projected to be a 200G world indefinitely. Although individuals at Microsoft can be found stating they would be willing to live with this situation, such large users will ultimately not put up with a very inefficient state of affairs from a cost point of view. In fact, it begs the important question: Why buy the Tomahawk 3, if ...

Read More

AOCs: Unappealing Choice Up to 30 Meters

September, 2018

Assuming Microsoft goes ahead with a proposed project of a flattened switch architecture in its data centers, the use of Active Optical Cables (AOCs) for the 0-to-30-meter lengths would undoubtedly remain under consideration, even though the operator is leaning towards the use of VCSELs. However, we believe there would definitely be obstacles to the utilization of AOCs in this application, which would probably make them inherently unattractive. It is interesting to note that from an installation perspective, as opposed to an inventory standpoint, Microsoft does not make a distinction between MultiMode Fiber (MMF)/VCSELs and AOCs. The deployment of either would be as if it were doing so with passive copper cable. In this article, we will also be looking at the future deployment of AOCs in general. One hurdle with AOCs in the 30-meter-and-under app, which would likely make Microsoft unhapp ...

Read More

Inphi Could Not Resist Hyperscale Vortex

September, 2018

fibeReality first used the term, “hyperscale vortex” relating to ADVA Optical Networking, as it was one of the examples of foreshadowing of the complete destruction of the optical ecosystem. Although ADVA’s CEO had reservations about getting too involved with the hyperscale data center operators, the vendor eventually succumbed to getting deeper into this quagmire. When it came to Inphi, the allure of joint development and marketing work with Microsoft when the supplier was still an up-and-comer had to be even more overwhelming. In our recent article, “Inphi’s ColorZ: New Buyer Constrictions,” we made the case that the product has fallen way short of expectations of deployment even at Microsoft. While we have tended to admire Inphi as a vendor in the past, from the beginning, anyone listening to its messaging would have received the distinct impression that for distances of 80 kilometers ...

Read More