FTP over IPSEC Tunnel

Hi,

I would like to know the limitations of using FTP over IPSEC Tunnel. I am facing typical problem in uploading and downloading data. I have 1Mb of Symetric Internet Bandwidth. I am trying to upload and download to my clients FTP server in US. I suppose to get 1Mb of upload/download, but that is not happening, I am getting 300K upload and 600K downloads.

Pls reply, should anyone require additional info.

Thanks in anticipation
Sayeed

The transfer rates you are seeing are not only dependent on having enough bandwidth. They also depend upon your TCP window size settings, buffers, latency, MSS etc.

If you have Windows machines on both sides, try to increase their TcpWindowSize.

http://www.microsoft.com/resources/...n-us/242669.asp

You can also use multiple FTP sessions to increase the bandwidth usage but this may slow down your machine, if they are already FTPing something else.

Please note that having too large an MTU may adversely affect your rate as de/fragmentation may occur.

HTH.
The Network Department

In addition, the fact that the entire data stream is encrypted by your vpn tunnel will reduce the effective transfer speed.

Just to hit on a little more on what Doug G was getting at using encryption will slow the transfer, as well the stronger the encryption the slower it will be, ie. 3DES vs DES or MD5 hash vs SHA1.