Please help on distributed database

The size of the database is about 30MB in paradox format.
It is shared among 10 users with ethernet orginally.

Now a remote site with about 10 users connected needs to
access the database too. I set up at NT server at both ends
and use a single modem to connect two sites. I implemented it
by Delphi 4 C/S with multi-tier.
I tried to use TClientDataSet in MIDAS with 100 packetrecords.
However, the performance is very bad since all queries from
the remote users need to pass through the modem.

Is there any solution that I can distribute the database easily? Also, do
I need to implement manually the recover procedure when the
data was modifed when the modem down?
or can I take advantage with the 'briefcase' feature?

Thank you very much.
Calvin