How many types of 100G QSFP28 optical transceivers?
“QSFP” is short for Quad (4-channel) Small Form Factor Pluggable, which refers to the package type; the number “28” indicates that the maximum transmission rate of each channel is 28Gbps. The main types of 100G QSFP28 are SR4/LR4/ER4/ZR4/SRBDPSM4/CWDM4. It's tricky to select a 100G QSFP28 optical module because those types have many similarities, such as cwdm4 vs lr4 . Therefore, t he need for transmission distance is considered first, then when the transceivers are at the same transmission distance, the final selection is based on fiber deployment and specific other needs.