Reversing roles of server and client for uploading sync list

[cjand8rs at gmail.com]

I am searched for an easy answer but I haven't come across one.
Basically the problem is that I have an ADSL network that I use to
remotely backup some files that have changed across and entire OS every
few days.

The problem I have found is that banddwidth up is about 50x greater than
that coming down (its about 20:1 but add noise on the lower 128KHz of
the 4KHz bins used to upstream and in reality it is about 50x).

When I sync from the machine at the end of the ADSL connection to
anywhere else the file list is always being SENT to by the machine with 
the slow upstream ADSL connection (swapping the destinations results in a
"building file list" as opposed to "sending the file list") and in both
cases it is acting as the "server".

Is there an easy way to change the roles only for syncing the lists, yet
allowing files to be sent in the other direction? Any experimental
patcehs would be welcome.