IIS 10 Windows server 2019 slow ftp high latency

Question

User-274927302 posted

Hello I have dedicated server with 1gbps of upload speed but I cant get over 10mpbs dowload speed from my client pc from ftp with iis 10. I have high letancy over 100ms. I know the problem is with window size but I cant edited from registry on windows server 2019. I have the autotuning at experimental. Could you help me with some solution.

Thank you

Answer 1

User1065476709 posted

Hi kaldim,

As far as I know, bandwidth will limit the download speed of the current website in iis. You can check the settings by clicking iis manager -> select website -> click "advanced settings".

You can try to increase the value of maxBandwidth: maxBandwidth.

Best regards,

Sam

Answer 2

User-274927302 posted

No this option is only for http not for ftp

Answer 3

User1065476709 posted

Hi kaldim,

I am very sorry for misunderstanding your question, In iis you can set the download speed through FTP request filter.

FTP request filter->edit feature setting->maximum cotent length

Best regards,

Sam

Answer 4

User-274927302 posted

Hello samwu

First of all thank you for your replys on my question.

The setting that you are refering FTP request filter->edit feature setting->maximum cotent length

is for the maximum size of the file that you give you access to download not for the speed. I need to make the buffer or the tcp window size bigger to fix my problem but in windows server 2019 ignores the values I added to the registry.

Do you know from where in iis i can change this value. I have try with filezilla that has 32768 bytes size of buffer and it work perfect but I need to run my ftp server through iis so filezilla server is not an option

Thank you

Answer 5

User1065476709 posted

Hi kaldim,

Do you know from where in iis i can change this value. I have try with filezilla that has 32768 bytes size of buffer and it work perfect but I need to run my ftp server through iis so filezilla server is not an option

Have you checked your network conditions? I think the upload and download speeds are also related to your network conditions.  Besides, you could try to set specific user for your virtual directory of the network share to ignore the permission issue in IIS manager->site node->basic settings->connect as->specific user.

This link also provide one solution to resolve this issue: https://social.technet.microsoft.com/Forums/windows/en-US/0b996be9-e605-458e-889f-39916f171b54/slow-download-but-good-upload-ftp-windows-server-2008-r2?forum=winserverPN

Best regards,

Sam

Answer 6

User-274927302 posted

Hi and mary Cristmas

Nothing of these suggestion helped out.

I will apriciate if someone  knows how to change the tcp window size in windows server 2019

Thank you

Answer 7

User1065476709 posted

Hi kaldim,

The download-related settings in the windows server are the ones I mentioned above, maybe you can try to find the reason for the slow download speed in others, such as the following article. https://techcommunity.microsoft.com/t5/networking-blog/top-10-networking-features-in-windows-server-2019-8-a-faster/ba-p/339749

Best regards,

Sam

Answer 8

User-274927302 posted

Hello Sam

I have allready have this settings I have a cubic protocol whith expirimental Window Auto-Tuning Level that is great for http protocol. I can download from http more than 10mb/s with high latency of 140ms.

But for the ftp things are very diffrent. With latency of 80ms I can download with top speed of 1,2mb/s and at 140 latency the top speed is only 80kb/s thats why I have to mannualy change the tcp window size to (1000000000(bandwith of server)*0.140(latency))/8= 17500000 bytes. My problem is that in windows server 2019 ignores the values I add it in the registry or I put them in wrong way.

Best regards,

Dimitris

Answer 9

User1065476709 posted

Hi kaldim,

My problem is that in windows server 2019 ignores the values I add it in the registry or I put them in wrong way.

Can you show me how did you add it in the registry?

Best regards,

Sam

Answer 10

User-274927302 posted

Hello sam,

This is a screenshot

https://imageupload.io/yOJvcHjhYY.i

Thank you

Dimitris

Answer 11

User1065476709 posted

Hi kaldim,

Did you reboot your computer? The TCPWindowSize registry require computer reboot to take effect. 

More information about TCPWindowSize you can refer to this link: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-2000-server/cc938219(v=technet.10)?redirectedfrom=MSDN

Best regards,

Sam

Answer 12

User-274927302 posted

Hello

Again is some one has the knowledge of the issue?

Thank you