SFP, SFP+, SFP28, QSFP+ and QSFP28 are the packaging types of optical modules. These hot-swappable optical modules can be used to connect network switches and other network devices (such as servers, etc.) for data transmission. Before clarifying the difference between these package types, you need to understand what the SFP, SFP+, SFP28, QSFP and QSFP28 packages are. Next ETU-LINK will give you an introduction to these package types.

SFP

SFP is the abbreviation of Small Pluggable, which can be simply understood as an upgraded version of GBIC. Its volume is only 1/2 of GBIC module. This design greatly increases the port density of network equipment. The transmission rate of SFP encapsulated optical module is 155M, 1.25G, 2.5G, etc. The interface type is mainly LC interface, which is generally used in SONET/SDH network, 100M/Gigabit Ethernet and other low-speed transmission applications.

SFP+

SFP+ and SFP have the same appearance and size. The transmission rate of SFP+ packaged optical modules is 6G, 8G, 10G, etc. The package types are 6G/8GFC optical modules, 10G optical modules, 10G copper modules, 10G DAC high-speed cables and 10G AOC active optical cable. SFP+ series products are mainly used in data center 10G (10GBASE-SR) Ethernet links.

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 provides an efficient solution for the upgrade of 10G-25G-100G network, which can meet the continuously growing demand of next-generation data center networks.

QSFP+

The QSFP+ package can support 4-channel transmission at the same time, and the data rate of each channel is 10Gbit/s, and the transmission rate of 40Gbps is realized through 4 channels. Compared with SFP+, the transmission rate of QSFP+ optical modules can reach four times that of SFP+ optical modules. QSFP+ optical modules can be used directly when deploying 40G networks, thereby effectively saving costs while increasing port density.

QSFP28

The QSFP28 package type is produced to meet the needs of 100G applications. It can support 4 channels of transmission at the same time, with a data rate of 25Gbit/s per channel, and a 100Gbps transmission rate through 4 channels. It can meet the application requirements of 100G Ethernet (4×25Gbps) and EDR InfiniBand.

After introducing the five encapsulation types, ETU-LINK will explain to you some of the differences between these encapsulation types. From the perspective of speed, SFP is an optical module packaging type with a speed generally below 3G; SFP+ is a packaging type for optical modules with a speed of 6G-16G; SFP28 is a packaging type for optical modules with a speed of 25G/32G; QSFP+ is a packaging type with a speed of 40G /56G optical module packaging type; QSFP28 is a 100G optical module packaging type.

From the perspective of the number of built-in optical components, SFP, SFP+, and SFP28 have built-in single lasers and single detectors, while QSFP+ and QSFP28 built-in 4-channel laser arrays and 4-channel detector arrays. And the interface protocols of these 5 encapsulation types are different.

The above is the introduction of ETU-LINK on the differences of the five package types. From the perspective of package size, the sizes of SFP, SFP+ and SFP28 are smaller than those of QSFP+ and QSFP28 (the two have the same size). By comparing SFP and SFP+ , SFP28 and SFP+, QSFP28 transmission rate and size, we can see that the main driving force for the development of optical modules lies in the pursuit of small size while achieving higher bandwidth.