100G Overview

One hundred gigabit is the speed at which modern core and data-centre networks run, and it is worth understanding what that speed means before planning a deployment around it. A 100G link carries ten times the traffic of a 10G link and two and a half times the traffic of a 40G link, in a single port, over a single module. That density is what makes 100G practical: a switch that once needed ten 10G ports for an aggregation link now needs one 100G port, with less cabling, fewer patch panels and simpler management. The cost per gigabit falls as speed rises, which is why 100G has become the default core speed even where 40G would technically suffice.

Where is 100G used? In data-centre cores, where traffic between rows and between halls grows faster than any other traffic. In data-centre interconnects, where two sites exchange traffic at a scale that makes lower speeds impractical. In carrier cores and metro cores, where aggregation traffic from thousands of access links converges. In high-performance computing, where nodes exchange data at a scale that makes 10G or 40G a bottleneck. In each case the driver is the same: traffic growth that outruns the previous speed, and a port count that becomes unmanageable at the lower speed.

Planning a first 100G deployment starts from the existing network rather than from the module catalogue. What speed do the aggregation links run at today, and how close are they to saturation. What fiber plant connects the sites or rows that will carry 100G, and is it single-mode or multimode, multi-fiber or duplex. What switches will carry the 100G ports, and do their ports support the variants planned. Those three answers — traffic, plant and equipment — narrow the module choice quickly, and the series pages on this site then narrow it to a title.

The fully specified 100G model on this site is the QSFP28 LR4, whose detail page states a 100G rate, a 1310nm wavelength, 10km and 20km reach options over single-mode fiber, 103.1Gb/s aggregate bandwidth, power consumption below 3.5W and a 0 to 70 degree Celsius operating range. Those figures belong to that model alone. The remaining QSFP28 titles are listed at series level. A buyer planning a 100G deployment should state the traffic, the plant and the equipment during the inquiry, so the answer can be specific to the deployment rather than general to the speed.

Before ordering, confirm quantity, price and delivery time during the inquiry. Certificates are available upon request.