SFP, SFP+, SFP28, QSFP+, QSFP28, QSFP-DD, and QSFP56 are all types of optical transceivers and AOC/DAC high-speed cables used in data center and networking applications. While they all serve similar functions, there are some differences between them in terms of their capabilities and specifications. Here are the main differences and similarities between these optical transceivers:

SFP: SFP stands for Small Form-factor Pluggable. It is the original form factor for optical transceivers and has a data rate of up to 4 Gbps. It uses LC connectors and can support both single-mode and multi-mode fiber.

COMNEN_SFP_SFP+_SFP28_QSFP+_QSFP28_QSFP-DD_QSFP56-Module_Transceiver

SFP+: SFP+ is an updated version of SFP that supports data rates of up to 10 Gbps. It is backward-compatible with SFP and uses the same LC connectors.

10G SFP+ DAC CABLES

SFP28: SFP28 is a newer form factor that supports data rates of up to 25 Gbps. It uses the same form factor as SFP and SFP+, but with upgraded components that can handle higher data rates.

DAC Cables 25G sfp28

QSFP+: QSFP+ stands for Quad Small Form-factor Pluggable Plus. It has four transmit and four receive channels, allowing it to support data rates of up to 40 Gbps. It uses MPO connectors and can support both single-mode and multi-mode fiber.

QSFP+ 40G DAC cables

QSFP28: QSFP28 is an updated version of QSFP+ that supports data rates of up to 100 Gbps. It uses the same form factor and MPO connectors as QSFP+ but with upgraded components that can handle higher data rates.

QSFP28 100G AOC cables

QSFP-DD: QSFP-DD stands for Quad Small Form-factor Pluggable Double Density. It is a newer form factor that supports data rates of up to 400 Gbps. It has eight transmit and eight receive channels and uses QSFP-DD connectors.

COMNEN 400G QSFP-DD DAC CABLE

QSFP56: QSFP56 is an even newer form factor that supports data rates of up to 200 Gbps per channel, or 800 Gbps total. It uses QSFP-DD connectors and supports both single-mode and multi-mode fiber.

200G to 200G QSFP56 DAC cables

In summary, SFP, SFP+, and SFP28 are all small form-factor pluggable optical transceivers and AOC/DAC high-speed cables that support data rates of up to 4 Gbps, 10 Gbps, and 25 Gbps, respectively. QSFP+, QSFP28, QSFP-DD, and QSFP56 are all quad small form-factor pluggable optical transceivers and AOC/DAC high-speed cables that support data rates of up to 40 Gbps, 100 Gbps, 400 Gbps, and 800 Gbps, respectively, with increasing numbers of transmit and receive channels and upgraded connectors.