Differences Between SFP, SFP+, SFP28, QSFP+ and QSFP28

SFP, SFP+, SFP28, QSFP+ and QSFP28 are all package types of optical transceiver modules. These hot-swappable optical transceiver modules can be used to connect network switches and other network devices for data transmission. Before figuring out the differences between these package types, we need to know what packages are SFP, SFP+, SFP28, QSFP and QSFP28.

SFP
SFP is short for small form-factor pluggable, which can be simply understood as an upgraded version of GBIC module, and its size is only a half of GBIC module. It refers to fiber optic transceivers supporting 155Mbps, 1.25Gbps, 2.5Gbps and 3Gbps data rate. The interface type is mainly LC interface. SFP transceiver is generally used in SONET/SDH network, 100M/1000M Ethernet and other low-speed transmission applications.

SFP+
SFP+ and SFP have the same appearance and size. The transmission rate of optical transceiver modules packaged in SFP+ form is 6Gbps, 8Gbps, 10Gbps, etc., and the package types are 6G/8G FC transceiver modules, 10G SFP+ transceiver modules, 10G RJ-45 connector transceiver modules, 10G DAC twinax cables and 10G AOC active optical cables. SFP+ series products are mainly used in 10G Ethernet links in data center.

SFP28
SFP28 is an enhanced version of SFP+, which has the same size as SFP+, but it can support a single-channel 25Gb/s rate. SFP28 transceiver provides an efficient solution for 10G, 25G, 100G network upgrades, which can meet the growing demands of next-generation data center networks.

QSFP+
QSFP+ package can support 4-channel transmission at the same time, the data rate of each channel is 10Gbit/s, and its transmission rate can be up to 40Gbps via 4 channels. Compared with SFP+, the transmission rate of QSFP+ optical transceiver module can reach four times that of SFP+ optical transceiver module. When deploying 40G network, QSFP+ optical transceiver module can be used directly, so as to effectively save costs and increase port density.

QSFP28
QSFP28 package type is designed for meeting the requirements of 100G applications. It can support 4-channel transmission at the same time. The data rate of each channel is 25Gbit/s, and the transmission rate of 100Gbps can be achieved through 4 channels. 100G QSFP28 transceivers can meet the application requirements of 100G Ethernet.

In terms of data rate, SFP is a package type for optical transceiver module with a rate below 3G. SFP+ is a package type for optical transceiver module with a rate range from 6G to 16G. SFP28 is a package type for optical transceiver module with a rate of 25G/32G. QSFP+ is a package type for optical transceiver module with a rate of 40G/56G. QSFP28 is the package type for optical module with a rate of 100G.

In terms of the quantity of built-in optical devices, SFP, SFP+, and SFP28 have a built-in single laser and a single detector, while QSFP+ and QSFP28 have 4-channel laser arrays and 4-channel detector arrays. Besides, the interface protocols of these five package types are different.

In term of package dimension, the size of SFP, SFP+ and SFP28 is smaller than QSFP+, QSFP28. By comparing the transmission rates and dimension of SFP, SFP+, SFP28, QSFP+ and QSFP28, we can see that the development of optical transceivers is to achieve higher bandwidth while pursuing small size.