We are building a 40G metro ring using 40-Gigabit Ethernet QSFP+ Transceivers. Specifically, we are using Juniper JNP-QSFP-40G-LR4. This is a QSFP+ Transceiver with a LC duplex head. We only have one pair of single mode dark fibers around the ring. Our distance between nodes around the ring are all less than 10KM, so we can use standard optics. We go out of one JNP-QSFP-40G-LR4 and into another JNP-QSFP-40G-LR4. There are no passive muxes involved. This is working great for 40G. My understanding is a JNP-QSFP-40G-LR4 is really a transceiver with a CWDM mux built into it. The spec sheet shows it sends 4 10G channels: https://www.juniper.net/documentation/en_US/release-independent/junos/topics... Lane wavelength Lane 0–1264.5 nm through 1277.5 nm Lane 1–1284.5 nm through 1297.5 nm Lane 2–1304.5 nm through 1317.5 nm Lane 3–1324.5 nm through 1337.5 nm This setup is working fine, but now we want to do more than 40G around the ring. To my knowledge there are no other 40G QSFP+ transceivers that use four other channel/lanes than the ones already being used, so they only way to go higher than 40G is to stack 10G or 100G channels ontop of the fiber pair using a passive mux. 100G is too expensive for the time being, so we are looking to add 10G channels to a ring that already have one 40G channel using the QSFP+. I was reading this tutorial, and it mentions "there is a 1310 nm port integrated in a 40 channels DWDM Mux/Demux system. The 1310nm added port is a Wide Band Optic port (WBO) added to other specific DWDM wavelengths in a module. When we run out of all channels in a DWDM Mux/Demux system, we can add the extra optics via this 1310nm port." http://www.fs.com/upgrade-to-500g-with-40ch-dwdm-mux-demux-system-aid-493.ht... What I can't seem to understand is they are mentioning that this 1310 port can pass QSFP+ signals, so it sounds like its really a 1270nm through 1330nm port? Is this what they mean by Wide Band Optic port (WBO)? We don't need 40 10G channels plus a 40G for a total of 440G. More than likely we are looking at a 8 channel mux/demux, and 1 40G port for a total of 120G. I don't care if we do CWDM vs DWDM, but I assume it will be hard to find a CWDM mux that has one LC dupluex input for 1270nm through 1330nm channels? Maybe I should just ditch the 40G QSFP+ optics and use all 10G optics, but the switches I am using have 48 10G SFP+ ports and 6 QSFP+ ports built in. I know there are 40G breakout cables, but the whole point of 40G is to aggregate VLAN/circuits. Has anyone done this before?