Folks-

We have a slow throughput problem with curl for uplink (from a W2K sniffer) to FTP server problems.

The root cause issue is TCP delayed ACKs. When a packet arrives at the FTP server the server will wait for 200 ms to send out an ACK if another packet is not received.

We can stop this behavior using the TcpAckFrequence setting in the FTP XP or W2K server, but I am worried this might affect other applications running on that server.

Does anyone know of a way to increase curl's buffer size from 0x4000 to, say 0xffff? Or is there a way for curl to open up the TCP window?

This behavior to a remote FTP server reduced the data rate to 500 Kbps.

Thanks, Joe
Received on 2008-03-27