You can make
SessionDatabase SQL count sessions in different ways depending on how you
want to restrict your sessions. For example, you could limit the number of
users permitted to log in to a particular realm with something
like:
CountQuery select NASIDENTIFIER, NASPORT, ACCTSESSIONID, \
FRAMEDIPADDRESS from RADONLINE where USERNAME like ?
CountQueryParam %%@%R
If your Session Database table included
the Called-Station-Id for each session, you could limit the maximum number
of users with the same Called-Station-ID with something
like:
CountQuery select NASIDENTIFIER, NASPORT, ACCTSESSIONID, FRAMEDIPADDRESS \
from RADONLINE where CALLEDSTATIONID = ?
CountQueryParam %{Called-Station-Id}