Network Transceiver terminology can be confusing. In essence QSFP28 and QSFP 100G mean the same thing. Originally the “QSFP” form factor was designed for sub 10G speeds. Then it was adopted for 40G, so the name became QSFP+ to denote the higher capacity performance. The “QSFP” form factor was further developed for 100G but the electrical interface had to be upgraded to handle 25Gbps/lane. The electrical interface for 100G can handle up to 28Gbps, hence the engineering and industry name is QSFP28. Many vendors, however refer to the 100G form factor as “100G QSFP” to avoid any confusion.
