The challenge of long distance connectivity
The QSFP28 is still the smallest 100G transceiver. It’s a fraction of the size of the CFP, and is perfect for short distances. For longer distances, there have also been some recent breakthroughs in transceivers with DWDM capabilities, most significantly the PAM4 . To be effective, however, the PAM4 requires amplification for even very short distances, and for any distance over 5 or 6km, needs dispersion compensation. With this, it can handle data traffic up to 80km.
While the range of choices for connecting 100G traffic is growing, no single small transceiver can solve the problem of connecting switches between data centers or other distant sites.
That’s why it’s not uncommon for organizations to consider full-blown, telecom-grade DWDM platforms to handle their 100G data center connectivity. These platforms take the output of the QSFP28 transceiver and run it through a complex web of transponders, amplifiers, signal conditioning, multiplexers and network management. It works, but these platforms are designed for the telecom, not the datacom world, which means they’re incredibly complex, and usually far overspecified for what are relatively simple traffic demands. But more importantly, they’re expensive, pushing the capex and opex for these systems far outside the range of what a corporate data center should need to spend, especially when DWDM is only required for a small percentage of standard Ethernet switch connections.
How corporate data centers can get the best of both worlds
The ideal solution would allow best-in-breed 100G switches and routers to be used within the data center, with low power consumption and a maximum port count – with a low cost per bit. And then, for those occasions where traffic from these switches and routers need to be connected over longer distances, or over a DWDM network, there should be a solution that is simple, easy to install and operate, and cost-effective to own and run. For a corporate data center, none of these are terms that could be applied to a solution designed for telecom systems.
The solution that offers the best of both worlds allows the user to get the full benefits of QSFP28 transceivers in the datacom equipment, but also gets the advantages of telco-quality traffic transportation between sites.
The Smartoptics DCP family is built exactly for this purpose. These modular, plug-and-play, low-powered transponders and muxponders can be placed close to the switches whose traffic they need to transport. They’re designed on an open networking philosophy that enables transponders and embedded DWDM to be used together with embedded DWDM transceivers, depending on the specific requirements of each network.
Rather than use expensive workarounds of products designed for huge telecoms carriers, corporate data centers can now use much simpler, plug-and-play solutions that are flexible, scalable, and designed to meet their needs.
For more on using QSFP28 transceivers for data center connectivity without sacrificing long-distance traffic needs, download the Smartoptics guide to simplifying 100G DWDM connectivity.