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v7.30.0 is slower than v2.29.0 when I upload files with FTP

From: Mike Mio <>
Date: Tue, 13 Aug 2013 12:22:42 -0400



I have a Win32 program that uploads web pages and their associated resources
to an FTP server. I originally used the libCURL version 7.29.0 and then
dropped in the v 7.30.0 dlls. After that change the transfers began taking
an extra 0.5 to 1.0 sec. (approx.) each. The delay seems to be between the
server response "150 opening binary mode data connection" and the client's
Data transfer.


These are mostly small files that I am uploading (200-4000 bytes). I am
using only the Easy interface.


The only difference I see (but I am no expert) is that in v7.30.0 the client
is responding to the "150 opening binary mode data connection" with an
ACK, the delay, then the FTP data whereas in v7.29.0 the client is
responding immediately with the FTP data.


I have tested this on several different FTP servers and with and without
SSL and I see the same thing. I also tried using v7.31 and it does the same
as v 7.30.


Any idea what is going on? Should I be changing some parameters? Is there a
known issue here?


Thanks in advance for any suggestions or insights you can offer.







List admin:
Received on 2013-08-13