This attribute counts the total number of cells containing silent fax
data received from the interface which were not forwarded into the
network, thus saving bandwidth. A channel may go into silence due
to the silence Suppression feature or for CAS channels when the
ABCD signalling bits go idle.
A cell contains 44 bytes of data from the DS0 channel (5.5 ms).
This flow is measured before compression is performed on the
channel.
This counter wraps to zero after reaching its maximum value.