You might have seen us touting our new generation of 100G SMF pluggable optics , called “ Single-Lambda 100G “. The final product we introduced was the 100G LR , which gives a 10km reach. We’ve now finalized the portfolio with the 100G ER-Lite .

The reach of ER-Lite is 25km. So that it can support links between a company’s campuses, between campuses of a data center cluster, and backhaul or fronthaul links in a radio network. It’s ideal for when LR’s 10km reach isn’t sufficient, and the 40km reach of our ER 4 -Lite isn’t needed.

Like 100G LR, 100G ER-Lite complies with a Single-Lambda 100G MSA specification, in the latter case “ LR1-20 .” Spot the true number 20 in the name of the spec. It’s a 20km reach specification actually. However the Cisco 100G ER-Lite supplies a 2 5 km reach when used at both ends of the optical link. We understand this extra 5km because of the clean modulator we’ famously;ve demonstrated at OFC before. Find out about it here watching a video about any of it here .

Imagine if you pair Cisco’s ER-Lite with another vendor’s LR1-20 compliant module at another end of the fiber? It’ll support the MSA’ still;s 20km reach, tied to the non-Cisco end.

As with most of Cisco’s single-lambda 100G QSFP28 optics, ER-Lite includes a special chip inside. It uses PAM4 modulation to send the 100G data stream with an individual laser source optically. In contrast, a lot of the earlier 100G optics send four streams of 25G NRZ either on four separate pairs of fiber, or with four lasers about the same fiber pair multiplexed by wavelength.

And that same internal chip incorporates a stronger FEC (Forward Error Correction) algorithm than what’s typically on the host switch/router/server. So don’t forget to show off that host FEC !

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