USR 56k Modem FTP Problem

[sibasis]

I have a FTP application to download/upload files from a FTP(IIS) server using the wininet API. The files download fine but if the file size of one text file is above 1.75 meg then the file transfer stops and cannot access the next file using the FTPOpenfile command.

I am using a USR 56 int modem, win2k pro, however if the transfer is done over the T1 n/w it works fine, plus if the transfer is done on another m/c win 2k pro with an external modem it works fine.

anybody knows what direction I should be looking at, the
VRAm settings on both computers for the modems is a bit different. I tried switching the external modem to the not working box.. samp prob. the problem occurs only when I am downloading data, uploading works fine.

 

[sibasis]

my modem model is 5867-53 and the issue is not alimit any more of 1.75mb text , if we transfer a file over 3 megs it works fine it just that at 1.75 mb it chokes or something.