Why are we receiving the request timed out error while copying files larger than 1 Mb using Winscp or FTP?

Issue

• When we copy more than 1MB large files through WinScp or FTP we are receiving request timeout to the server. Why?
• Why am I not able to copy large files from my windows workstation to my RHEL host using winscp? However the vice versa works fine,i.e transfer of large files using winscp from my RHEL host to the windows workstation works fine.
• Linux to linux scp/ftp for large files works fine but not for Windows to Linux. Also, I am not sure why Linux to Windows works well though.