Vlog #10 How VSFF connectors improve data center sustainability


OSI Insights in our video-blog

The issue of sustainability is becoming ever more important in the data center world. What role does the passive infrastructure, and in particular the small components, have to play here?

New Very Small Form Factor (VSFF) plug connectors such as SN® and MDC are currently making enormous progress. These make it possible to transmit ever higher data rates. How do these connectors also help improve sustainability in data centers?  

Here to discuss these questions are: Slavko Mucic from Sales and Harald Jungbäck, who works in the Data Center Product Management sector at Rosenberger OSI.

Here, we place the focus on: An overview of VSFF connectors | SN® and MDC use cases 


What are these new VSFF plug connectors all about and how can they contribute to improving sustainability in data centers? I have asked my colleague Harald Jungbäck here to talk about this issue. Can you tell us what these new connectors are all about?

Harald Jungbäck: To illustrate this, I’d like to show you something. There is the MDC connector from US Conec and the SN® connector from Senko. Both belong to the new VSFF category: Very Small Form Factor connectors. I’ll show you why these new connectors are here and what we need them for by means of an example. The starting point in the development of these connectors goes back quite a few years. It lies in the optical transceivers. To be able to transfer higher data rates than can be achieved using traditional duplex applications, you need parallelization. Traditionally, this has been done using transceivers. For example, parallelization is implemented here using an MTP®/MPO connector with 8 fibers over 4 so-called lanes to achieve the current value of 400 Gigabits. 100 Gigabits per lane in the conventional way using the MTP®/MPO plug connector. All of this is increasingly being done via transceivers with 4 MDC ports as in our example, or alternatively 4 SN® ports.

Why this difference? Why have these two designs? Why not just do things via duplex applications as in the past? The reason is the port breakout. If you want to tap this then you need a harness or cassette structure. Here, however, you can lead the ports away from the transceiver using separate patchcords. That is the main reason why these new small MDC and SN® VSFF connectors were developed. What is more, they make use of ceramic technology and all its advantages. Robust, exceptionally low insertion loss, higher return loss than is possible with MTP®/MPO technology.

With regard to sustainability, how can this change of system help improve sustainability in data centers? 

Harald Jungbäck: Let’s take the following example and say that they are both 400 Gigabit singlemode, 500-metre transceivers. 400G DR4 will become a very dominant protocol and if I implement that with these QSFP-DD, then I have only 8 Watts each. It consumes 8 Watts and gives off correspondingly little heat. If I do that in the conventional way as in the past, then I have four individual 100-Gigabit QSFP-DD transceivers operating in singlemode with an LC Duplex interface. So I have four of them. And each of them consumes 4.5 Watts. That means I have a total of 18 Watts, and the heat emissions that involves, compared to just 8 Watts. The really great lever here is the transceiver technology. Here, there is less power consumption, less heat dissipation and, of course, there is the question of the chassis, the switches, the servers in which it is all installed. Clearly, this takes up less space than the original four and the hardware itself is also more efficient. That is the driver. Correspondingly less electricity is needed in the data center, both for power and also for cooling.
And then the connectors naturally make their contribution in the passive infrastructure due to their density. The maximum possible today is 4 rows with LC Duplex or also with MTP®. And, of course, we have the push-pull variant. That gives us 96 ports per height unit. With LC Duplex, that makes 96 duplex ports. That is what is physically possible. If we were using MTP®, then we could implement all this with PreCONNECT® SEDECIM MTP®. We would then have 8 duplex ports per MTP®, 96 of them naturally gives us an enormous number of duplex ports. However, if I don’t want to do that and decide to stay with duplex ceramic technology, then these new VSFF connectors make it possible to increase the port density in the panel.
Let’s go back a bit. The conventional solution, 72 ports with LC Duplex. With MDC and SN®, we easily have 128 ports in the panel. It’s a bit crowded and dense of course, but it’s manageable. And that is the contribution to densification: reduced space requirement for racks, meaning that less space is used in the frequently valuable cooled environment. This obviously also helps save resources and consequently increases the density of the passive infrastructure and improves data center sustainability.  

More information on the subject of The need 4 speed - volume 6: 400/800G update and 1.6TB optical transceivers can be found here.