J3 (the black connector on the left) is always fitted to connect a 'low jitter daughterboard' and J5 & J6
J6 is a u.FL connector to which the clock output of the
Low-jitter-daughterboard can be connected.
J5 is used to select between the existing oscillator or the
Replacement of obsolete components (most notably a different NAND
Backplane (carrier board) 3.3.1
The backplane has been modified so the fans are always on (in the
original backplane 3.3 design the fans are controlled by software). This
keeps the hardware cooled in all circumstances.
Also more sturdy SFP cages have been used.
A Low-jitter-daughterboard gives a significant improvement when it comes
to the jitter performance of the White Rabbit switch.
The following pre-packaged firmware files are available: