Incredible network speeds are moving out of the lab and into commercial use! 400G is here with several different standards that can be right for your application. Let’s dive right into the leading emerging format: the QSFP-DD 400G and the available variations.
Note1: MPO connectors have a default polish based on their fiber type. The default for singlemode fiber is APC, the default for multimode fiber is UPC. The SR8 uses a special Multimode MPO16 with an APC polish.
400G: Lanes, Speed and Compatibility
Let’s start with lanes. The lanes we are talking about are the electrical lanes that communicate with the transceiver, not necessarily the number of lasers or fibers used. The SFP, SFP+, SFP28, and SFP56 transceivers are single lanes with speed limits of 1,10,25, and 50Gb in each direction. The QSFP+, QSFP28, and QSFP56 have 4 lanes, each with a speed limit of 10, 25, or 50Gb that can combine for 40, 100, or 200Gb. The DD in QSFP-DD stands for double density which comes from the doubling of these electrical lanes on the connector. These additional contacts are similar to the current QSFP just adding an additional row on the top and bottom, allowing backwards compatibility to be supported.
How the QSFP-DD allows for backwards QSFP compatibility.
Let’s talk about how 400G works, shall we?
When it gets to the optical stage, the applications diversify. There are several different 400G standards and picking the one right for you can be tricky. The QSFP-DD FR4 transceivers can provide incredible bandwidth across the facility if it’s needed, making centralized data storage more attractive as an example. The DR4+ uses 8 fibers of an MPO12 to break out bandwidth to four 100G QSFP28 FR transceivers. The reach is perfect for within the same rack, elsewhere in your building, or across campus. In the interest of standardization and sparing, this is our recommendation. It will allow you to get volume discounts, efficiency of reduced part diversity, and cut down sparing costs.
How to Determine if 400G is Right for You.
With bandwidth demand ever increasing, the better question is, “Is 400G right for me, right now?” If you are planning router upgrades, it would be a mistake to pass up support in some fashion for QSFP-DD with its augmented internal fabric capacity and power availability. While not really a long-haul format yet, though we will eventually see 400G ZR and ZR+ distances, the limited distance 400G and 4x100G transceivers are ready for prime time. In offices and datacenters the use of higher speed connections eliminate some of the more severe bottlenecks that mitigated productivity and communication.
Integra Optics leads the way in technology, quality, and reliability with a wide catalog of transceivers that won’t void your warranty and carry a lifetime guarantee. Whatever QSFP-DD variant you go with, buying from your trusted partner will get you what you need at a price you can live with. Our engineers are here to talk through the right 400G variation for your application; setup a time to talk with them!