wu-2.6.1 FTP SERVER

[Jennifer]

Dear FreeBSD people,


May I ask you an question about our ftp server's connection problem. 
We use Wu-2.6.1 as ftp server, which is running on Freebsd 4.3.
The part of FTP setting (simple type) is  like this in  rc.firewall?

 
#Allow access to our FTP
${fwcmd} add pass tcp from any to ${oip} 21 setup
#for passive FTP. we also need to allow for setups
#to ports in a high range (49152..65575), see ftpf(8)
${fwcmd} add pass tcp from any to ${oip} 49152- setup

This setting will allow ftp being accessed generally, but there is some minor problem. 
1. I found when I am not choosing the passive mode to connect to ftp server from client side machine, the file transfer and conneciton is going much faster and smoothly.
2. But when I choose passive mode (which is defaul setting for ws-ftp Le), the transfer goes much slowers, and even you are connected to the ftp server, for excute each ftp (ls, upload, download, etc) command, the client side has to connect to a server's port (higher range one ) again, which sometime succeed, some time fail, so takes much longer time than the NON-passive mode way. I put a log file at attached for your reference.

Do you think the above situation is normal? In this case, the passive mode seems not really good when considering the tranfer speed. So how can we overcome the problem of  EVERY TIME THE CLIENT SIDE HAS TO CONNECT TO A SERVER'S HIGH RANGE PORT FOR EACH COMMAND WHEN IS PASSIVE MODE? 

Thank you very much

Jennifer