Archive for the ‘File Transfer’ Category

File transfer in the Windows server family

Sunday, March 21st, 2010

The story of File Transfer as an IETF RFC standard started in the year 1971 and after that it took over 20 years to become what it is right now. The last version of the FTP protocol was code named RFC 959 and was developed in the year 1985 and it is still the same service, with minor changes in specifications.

IIS FTP Service
The main idea of the IIS ftp service in the Windows server family is to have a reliable place where you can store all needed information for your business, personal use and so on. The main Windows platform we will use as an example is Server 2003. In this OS, we have the option to install the integrated pack for using the FTP service. Of course it up to each customer, or just a single user, to have any other software solutions, but my experience with the built in services in the windows family will help me explain to you, more detailed info about the integrated service.

First of all in the Server, you will have to select the IIS or internet information service that you can add to host a FTP server on the local machine. It’s important to have the IIS turned on, because it also provides a GUI of the FTP service, which is very user friendly and much easier to use.

Setting up IIS FTP Server
The first step is to add the service by installing it using the add remove section in the control panel. Then, you have to add various user accounts to the service. The most important part of the setup of FTP are the following steps. After the installation you will be able to assign an IP in order to use it. If the IP is internal, for example ,you will be also able to use it locally, but also have in mind that you are probably behind a router and you will have to prepare the Router to accept and allow FTP connections on port 21.

The second step is to add the exception in the windows firewall for port 21. This means, that you will be able to use the FTP over the net. Without this step, you can only access the service locally. The next step is to add the directory, which will be the root directory, and after that, there will be stored the local user’s directories, which will be used. You will also need to set up the directory and provided User’s rights to each of these directories. The user himself, can use several programs to access the FTP server. He is supposed to have a User name and password/already granted by the server’s admin, They can use an FTP client in passive or active mode. The user information can be storeed over the network or locally using the File transfer protocol in the Windows OS server family. However, keep in mind that FTP itself is not too secure as a service and most of the modern system administrators may need to switch to SFTP, which is more secure.

File transfer in a global workspace

Sunday, March 14th, 2010

Using file transfer in business
In this modern age of information technology file transfer between multiple sites is common place, Businesses are often spread across multiple sites or required to supply files to clients and suppliers in many different formats and locations. Still common is file transfer protocol or FTP,  and often businesses have a presence in FTP that allows them to send and receive files easily.

This is a method that works well in the majority of cases and putting aside the security problems associated with this it is a good alternative to email when message limits exist in many corporate environments (large email solutions exist but this are often with third parties such as One of the downsides of file transfer starts being apparent over long distances – ftp bandwidth starts to suffer over these distances due to the nature of the TCP protocol that FTP sits ontop of. This often creates the feeling of ftp latency and an increase in the bandwidth for the FTP application.

TCP is optimised for accuracy in its data stream rather than getting the data to its destination in a timely maner. This often creates long delays (upto seconds) while the stack is waiting for out of order messages or retransmission of lost messages or packets. TCP reacts to out of order messages or lost messages by reducing thr transmission window size which increases the latecy by only allowing a few messages to be sent at any one time untill they are acknolgedged by their destination.

Increasing FTP Bandwidth 
As bandwidth becomes ever cheaper businesses are starting to notice they are not getting the best performance out of their FTP bandwidth and an alternative solution is required, in large digital agencies where getting content and files across the globe needs to be accomplished as soon as possible the latency that comes with FTP and other TCP based file transfer solutions is not acceptable. 

For a few years now, applications have started to appear on the market that take advantage of TCP’s alternative known as UDP. This protocol does not worry about reliability or order in which the messages arrive at their destination, This means that business are able to fully utilise their file transfer bandwidth. This in itself however, raises other issues, The most prominent is the order in which the messages arrive and how to handle lost data, this is often resolved in the application layer and requires the application to request lost packets or reorder packets that have arrived in the wrong order. This would create an extra overhead on CPU and machine performance but this has little effect in today’s computing power and is one that is acceptable in most scenarios to achieve the best ftp bandwidth and reduce ftp latency.