I use FileZilla and if you have 'use multiple connections' enabled (it is by default), it will keep the connection alive by doing stuff like this every few seconds:
Code:
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	TYPE A
Response:	200 TYPE is now ASCII
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	REST 0
Response:	350 Restarting at 0
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	REST 0
Response:	350 Restarting at 0
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
Command:	TYPE I
Response:	200 TYPE is now 8-bit binary
_________________________
-Rob Riccardelli
80GB 16MB MK2 090000736