What Is FTP? Differences from HTTP
"Web browser support"
"Most common web browserscan retrieve files hosted on FTP servers, although they may not support protocol extensions such as FTPS."
"When an FTP-(rather than HTTP)-URL is supplied, the accessible contents on the remote server are presented in a manner that is similar to that used for other web content."
"A full-featured FTP client can be run within Firefox in the form of an extension called 'FireFTP'."
FTP has a stateful control connection which maintains a current working directory and other flags, and each transfer requires a secondary connection through which the data are transferred. In "passive" mode this secondary connection is from client to server, whereas in the default "active" mode this connection is from server to client.
This apparent role reversal when in active mode, and random port numbers for all transfers, is why firewalls and NAT gateways have such a hard time with FTP.
HTTP is stateless and multiplexes control and data over a single connection from client to server on well-known port numbers, which trivially passes through NAT gateways and is simple for firewalls to manage.
"HTTP essentially fixes the bugs in FTP that made it inconvenient to use for many small ephemeral transfers as are typical in web pages."
Setting up an FTP control connection is quite slow due to the round-trip delays of sending all of the required commands and awaiting responses, so it is customary to bring up a control connection and hold it open for multiple file transfers rather than drop and re-establish the session afresh each time.
In contrast, HTTP originally dropped the connection after each transfer because doing so was so cheap.
"While HTTP has subsequently gained the ability to reuse the TCP connection for multiple transfers, the conceptual model is still of independent requests rather than a session."
When FTP is transferring over the data connection, the control connection is idle. If the transfer takes too long, the firewall or NAT may decide that the control connection is dead and stop tracking it, effectively breaking the connection and confusing the download.
"The single HTTP connection is only idle between requests and it is normal and expected for such connections to be dropped after a time-out."
Today, I simply want to upload images from my computer files to my wordpress site. Usually this is a simple step, but for unknown reason my images will not load occasionally and not right now.
I am advised by WA Support to do the training about FileZilla and FTP. No clue what either of them are, except for what you have explained in this training.
I've been uploading images to this same website for 3 years without filezilla or ftp.
I am not in the mood for technical training and I have my fingers crossed that you have a simple suggestion so that I can just get on with adding images and posting content.
Ignore my frustration and thanks for any advice.
Janelle
Reply
Some other times, just like me that still continue learning, this kind of technical stuff if we understood more, can help our life easier.
Just take a step at once learning, my friend. Everybody is the coaching hands right here at WA. I could learn from you too, my friend. Cheers! :)
Just because the service has its own vulnerability in a certain aspect and if ever anybody come across this service and kinda gets stuck with vulnerability issue, they can always fall back to this introduction and tutorials.
Thanks and welcome :)
It is the reason take closer interest and get involve with the memmbers for dot.org site let say to understand further its vulnerability among others.
It is really good tools to develop the direct from our owh system and network... next i think i will cover on security issues and also host of FTP providers etc for easy references.
Some other times, i found out certain review on open softwares etc not being kind to these group, team, or guys.
But not all or I mean this is subjective. Opinion of course divided but I'm giving the point of through my direct approach or engagement etc. It is a two sided world of free tools etc and world of capitalism where even a piece of advice has it own invoicing.
