Excessive connection utilisation

[Telcontar]

I'm posting this in the hope that someone, somewhere might know what's going on.

On my Windows 2000 desktop PC (Linksys BEFSR41 router and 2000/200 cable connection) I've got FlashFXP 3.6.0 and BulletProof FTP 2.1.6 server.

Upstream speed from both FlashFXP and BulletProof is the full 26 kB/sec, but FlashFXP completely swamps my Net connection and makes it effectively unusable. If I upload a large file to an FTP site (any site) via FlashFXP, that's my Internet connection down the drain for up to an hour or two. If someone downloads the same file from my FTP server, the transfer speed is exactly the same, but I wouldn't even notice anyone was using my connection except for the BPFTP tray icon changing colour.

I've spent ages poking around in TDIMon looking at packets and forcing FlashFXP to allow 1 kB packets even though that's outside of the limits of its UI, but I don't have any metrics here, no way to definitively measure the "swampiness" of different packet sizes. Trying to do it empirically does my head in as the effect seems to vary from one minute to the next.

Besides, if the answer actually is to use 1 kB packets, I can't force this on FlashFXP as it doesn't use a combo box and this packet size is out of range, and will get put back to the default any time I update the settings.

For many years, I've just accepted that FTP uploads are just an abomination on this planet (on any OS, any client) but BPFTP opened my eyes, demonstrating identical speed with no stress on my connection.

Anyone know what the secret is here? It would be much appreciated!

Cheers

[CandyHe]

upstream bandwidth is always a lot less than downstrean bandwidth,so you'd better check what's the upstream bandwidth on your ISP connection.If you can't limit the speed on uploading at flashfxp,do it on the ftpserver,most ftp server has option to limit the download or upload speed.

[JGOe2s]

he means that when he has upload traffic via bpftp server, he has no problem downloading at fast speeds.
When the upload traffic is created by flashfxp, he does lose his fast downloading speed.

I always experienced slow download when upload, so I'm actually quite curious if anyone knows.

[MxxCon]

why do you think that setting FlashFXP to use 1kb packets will change anything?

in FlashFXP, have you tried adjusting tcp/ip transmit buffer size?

[bigstar]

When uploading with flashfxp is the connection plain ftp?

I'm waiting on a software upgrade for a tool that monitors winsock sockets, once I get it I'll be able to look into this more closely and get back to you.

[Telcontar]

MxxCon: That's what I mean. The larger the buffer size, the more stress a program puts on the connection. However, the smallest size allowed in FlashFXP is 4 kB (IIRC). I have a feeling that BPFTP also uses a 4 kB buffer size (as shown by TDIMon) so that seemed to have been a red herring.

bigstar: Yes, plain old FTP. (Nice to see that 3.8 will support SFTP though! yay)

[Telcontar]

Hmm that's curious. FlashFXP can't identify my current send buffer size, which makes me wonder if it's still set to 1 kB after all this time. I used to know which setting it was, but not any more. I've got this:

SPS=8
RPS=17

But my receive buffer is 128 KB. There's also:

CB6=128
...
CB10=128

But it's not either of those. Nothing else in FlashFXP has "128" in it. I don't think we're ever meant to touch the INI file ;)

Whatever I did set the buffer size to (!) it's obviously not helping. One factor that does come into play though is (obviously) RTT -- an upload to a site more local to me is making the Web not quite as slow. This FTP site is extremely responsive, while most FTP sites -- all on the far side of the Atlantic, if not the far side of the US on the far side of the Atlantic -- tend to crawl a bit (think of connecting when the server and client chat for a while).

I guess TRWTF is the Windows packet scheduler.

[bigstar]

SPS & RPS are the correct entries and a value of 1 would be 1 KB.

However I really don't think a smaller packet size would solve the problem. I'm in the process of doing some testing and when I'm done I'll let you know what I come up with.

[polidex]

I am experiencing similar issues downloading and
browsing, while uploading files, with FlashFXP.
================================================== =========
Specs
================================================== =========
Windows XP Professional
V5.01 Build 2600 SP2 Micro-Star MS-7255
CPU Intel Core 2 Duo E4300 (Allendale) 1.80GHz
Ram 1gig

Connection type: DSL - Speedlink USB

Using Standard FTP connection.

Versions used:
FlashFXP 3.6
FlashFXP 3.72 BETA
================================================== =========
Symptoms
================================================== =========
- download connection unusable.
- web browsing impossibly slow.

:)

[MxxCon]

this is normal with very asymmetric dsl connections.
when you completely saturate your upstream, download's ACK packets get queued, which in turn causes those slowdowns.
if you cap your upload speed 5-10kb below it's maximum, that will virtually solve your slow browsing issue.

[polidex]

I do not agree that this is 'normal' as earlier versions of flashfxp do not exhibit this behaviour (I have tested a couple) and neither do the main ftp clients - and like most here I have tried quite a few. The last time I tried them all (say about 13) was about 48 hours ago, just before I purchased a flash fxp license - not one exhibited this behaviour and not one help file suggested cutting your connection speed so that it actually works properly.

With an upload speed capacity of about 30K, the idea of limiting it by one third so I can still browse is rather funny. Not what I expect from an ftp client. Because many people use an ftp client with the express desire of uploading and downloading/browsing at the same time without needing recourse to special settings and/or capping limitations. It's just one of those ftp simplicity things.

You know it might require looking at.

:)

[Telcontar]

SPS & RPS are the correct entries and a value of 1 would be 1 KB.

That's kinda what I thought, except the drop-down menus in the GUI do not match at all. 8 != blank and 17 != 128. I don't even know how 17 got in there -- that's nothing I've done.

this is normal with very asymmetric dsl connections.

This is true, yes. Fetch on Mac OS 9 would clog up my connection too. However, if BulletProof FTP can do it, then there is a solution somewhere. I'm just curious to know the arcane secret, as it would make a lot of people very happy.

Because many people use an ftp client with the express desire of uploading and downloading/browsing at the same time without needing recourse to special settings and/or capping limitations.

Well, yes. Not only does FlashFXP not have a way to limit the current session (that I know of?), generally this issue is a problem with large files. As in, 100 MB or more files where you have to leave them uploading for an hour or two. When you are using the PC, you'd have to drop the speed, and then raise it again when you're away from your PC. Otherwise, your PC might sit there for hours trundling along at pitifully slow speed because you forgot to remove the limit when you walked away from it.

[bigstar]

After further investigation I believe the excessive utilization you experience is due to our aggressive method of trying to send the data as fast as physically possible, Scaling up to handle the fastest gigabit speeds.

I think the one reasonable solution might be to have two modes, aggressive and relaxed.

I'm not 100% sure if this is the case and the only way we can be sure is if we can get you to test a special build compiled with a relaxed transfer method. At slower speeds you shouldn't see much of a difference but when scaling to gigabit there may be a slight (1% to 5%) loss of speed.

I am contacting you via a private message regarding the test build.

[Telcontar]

Hm ... I'm uploading a big juicy file for a friend (a jx3p DJ mix ;-) and Web access isn't exactly speedy. It does seem to be be an improvement though -- more like decent dial-up instead of like tin cans and wet string.

I'm not on gigabit though -- I'm only on a 100 Mbit LAN and only transfer very small files to and from my old Mac and that's it (I used to do that with FlashFXP too until I got an SMB package (DAVE) set up in Mac OS 9). All my large transfers are via the Internet.

Thanks for the test version.

[Edit: Actually, right now it feels like dial-up would be fast train overtaking my hand-cart.]