This document will focus on QSFP, QSFP+ and QSFP28.
Though they look very similar in physical appearance but the transmit data
rates are quite different.
QSFP,
QSFP+ and QSFP28 transceivers look very similar because they all share the same
small form-factor. The QSFP has evolved to QSFP+ to meet 10 Gbps data
rates. The standard is the SFF-8436. Further demand for higher data
rates led to introduction of QSFP28 which supports up to 100 Gbps of
speed.
QSFP
Abbreviation
stands for Quad Small Form Factor Pluggable.
QSFP is
available for use in both singlemode and multimode and can support 4
independent channels that can individually transmit at up to 1.25 Gbps per
channel for an total speed of above 4 Gbps.
QSFP28
combines speeds of 28Gbps per channel for a total speed of 100Gbps. The QSFP28
interface is highly flexible and can be used in the following combinations. ·100 Gbps ·2 X 50 Gbps ·4 X 25 Gbps
Usually QSFP28 modules can’t breakout into 10G links. But if a QSFP28 module is
inserted into a QSFP+ port, a QSFP28 can break out into 4x10G.
