DAC connection scheme:

①100G QSFP28 DAC direct connection: both ends are 100G interfaces, suitable for short distance stacking and direct connection between 100G devices for the same rack;

② 100G QSFP28 DAC connected to 4*SFP28 DAC: suitable for interconnection between 100G and 25G devices where one end is a 100G interface and the other end is four 25G interfaces, supporting a range of distances from 1 meter to 5 meters;

③40G QSFP+ DAC direct connection: both ends are 40G interfaces, suitable for stacking and interconnecting between 40G devices over short distances, with a maximum transmission distance of 7M;

④40G QSFP+ DAC connected to 4*SFP+ DAC: suitable for interconnection between 40G and 10G devices where one end is a 40G interface and the other end is four 10G interfaces, with a maximum transmission distance of up to 7M.

AOC connection scheme:

①100G QSFP AOC direct connection: both ends are 100G interfaces, using OM3 fiber transmission distance of 70m, using OM4 fiber transmission 100m;

② 100G QSFP28 AOC connects 4*SFP28 AOC: applicable to the interconnection between 100G and 25G devices where one end is a 100G interface and the other end is four 25G interfaces;

③40G QSFP+ AOC direct connection: both ends are 40G interfaces, using OM3 fiber transmission, suitable for interconnecting 40G devices within 100m;

④40G QSFP+ AOC connecting 4*SFP+ AOC: suitable for interconnecting 40G and 10G devices, using OM3 fiber optic transmission, with 40G interfaces at one end and four 10G interfaces at the other end.

In the actual application of 1-5M distance is recommended to use DAC high-speed cable, 7-100M is recommended to use AOC active fiber optic cable, more than 100M is recommended to use optical modules and fiber optic cable connection.

Additional Learning Hub Resources

What is the difference between AOC and DAC 

What is the difference between OM3 and OM4 

Four common types of 100G QSFP28 optical modules 

100G QSFP28 DR Single Wave Optical Module Working Principle and Advantages 

Difference between 100G single wave optical module and traditional 100G optical module 

Summary of common problems in the use of optical modules