Thank you, johnrbaker for examle of security configuration!
But it does not reolves my problem.
I find out the problem persists downloading files via ftp, but on http everything works fine - download speed equals WAN speed.
If somebody downloads file via ftp logs on SRX210 looks like this:
Session ID: 57798, Policy name: nat_list/6, Timeout: 1738, Valid
Resource information : FTP ALG, 2, 0
In: 192.168.0.7/45411 --> 204.152.184.73/21;tcp, If: ge-0/0/0.0, Pkts: 20, Bytes: 1084
Out: 204.152.184.73/21 --> 62.117.117.20/4326;tcp, If: fe-0/0/2.0, Pkts: 34, Bytes: 2213
I already turn off alg in security ( set alg ftp disable),
now logs looks like this:
Session ID: 58935, Policy name: nat_list/6, Timeout: 1754, Valid
In: 192.168.0.7/42625 --> 204.152.184.73/21;tcp, If: ge-0/0/0.0, Pkts: 24, Bytes: 1532
Out: 204.152.184.73/21 --> 62.117.117.20/26887;tcp, If: fe-0/0/2.0, Pkts: 35, Bytes: 2679
But it still does not reslove the problem... Downloads via ftp is still too slow.
I still need help.