Hi,
This may be a silly question as I'm not familiar with details of ssl.
My usenet provider supports ssl but they are also pitching it as an accelerator. Reading the setup guide http://www.newshosting.com/en/newshosti ... erator.php it looks like it's the zlib feature of ssl that they are using to do this.
So far I have configured UE to use SSL on the port specified in their guide, however I was wondering if this would be using zlib compression or not?
Thanks,
Al
zlib compression?
Re: zlib compression?
Does SSL slow transfer rates for downloading of Headers or attachments? (As opposed to normal non SSl transfers) (Normal = NNTP?)alnixon wrote:Hi,
This may be a silly question as I'm not familiar with details of ssl.
My Usenet provider supports ssl but they are also pitching it as an accelerator. Reading the setup guide http://www.newshosting.com/en/newshosti ... erator.php it looks like it's the zlib feature of ssl that they are using to do this.
So far I have configured UE to use SSL on the port specified in their guide, however I was wondering if this would be using zlib compression or not?
Thanks,
Al
And if so does this zlib compensate for the slowdown?
OR
Is SSL with zlib faster than standard (NNTP?) transfer rates?
AND
Stunnel is required for SSL connections?
Just wondering because if it's not faster.....Do I really need or benefit from it? After all is it that important for me to have SSL (I assume for a secure connection) I am well within in the law (as are most Usenet subscribers)and do nothing to warrant the need for extended security measures, especially if it cost me a reduction in transfer speeds....
canot find zlib option.
i cannot find the zlib option, so i guess it is automatic.
Would be nice if ue showed once if it is available, or if it is not available on the server?
Would be nice if ue showed once if it is available, or if it is not available on the server?
i used openssl.exe to test, i could add a message box warning user when the server doesn't support zlib compression, from other side if they switch off zlib compression temporarily you may get a false-like warning then.
formally zlib is applied per ssl session (ssl connection life span), not per task, just in the headers case it is effective, as to bodies since they are already compressed so you won't notice difference in speed.
you don't need to use stunnel or to do anything at all (just newshosting put a manual for those clients that don't support zlib compression), if you use ssl the compression is engaged automatically when available on the server.
to test whether your server supports ssl zlib compression download
http://www.netwu.com/ue/openssl.zip
run openssl.exe then type:
s_client -host news.giganews.com -port 443
Compression: None
Expansion: None
then e.g. if you type
s_client -host secure.usenetserver.com -port 8080
you see:
Compression: zlib compression
Expansion: zlib compression
zlib doesn't slow down anything, you get just much faster speed with headers and the same speed with bodies (if someone posted non-compressed file like .wav or .bmp, then you get higher speed with bodies as well unless (if there is such an option) the zlib compression was specifically tweaked to run in non-compression mode on article tasks. but zlib requires more CPU power on the server side, it is why it was disabled in the past, on the user side there is no overhead whatsoever, usenet providers just maybe added more CPUs.
formally zlib is applied per ssl session (ssl connection life span), not per task, just in the headers case it is effective, as to bodies since they are already compressed so you won't notice difference in speed.
you don't need to use stunnel or to do anything at all (just newshosting put a manual for those clients that don't support zlib compression), if you use ssl the compression is engaged automatically when available on the server.
to test whether your server supports ssl zlib compression download
http://www.netwu.com/ue/openssl.zip
run openssl.exe then type:
s_client -host news.giganews.com -port 443
Compression: None
Expansion: None
then e.g. if you type
s_client -host secure.usenetserver.com -port 8080
you see:
Compression: zlib compression
Expansion: zlib compression
zlib doesn't slow down anything, you get just much faster speed with headers and the same speed with bodies (if someone posted non-compressed file like .wav or .bmp, then you get higher speed with bodies as well unless (if there is such an option) the zlib compression was specifically tweaked to run in non-compression mode on article tasks. but zlib requires more CPU power on the server side, it is why it was disabled in the past, on the user side there is no overhead whatsoever, usenet providers just maybe added more CPUs.
you just need to use their ssl server.
'sslreader.eweka.nl', poort 563 you need to check SSL.
does it work with them?
i don't have account, i just checked it accidentally with openssl.exe, it shows zlib compression enabled.
it is also possible they are resellers of some other usenet service which i've randomly tested, i don't know them really.
you should see header speed increase like 2.5 times, with UNS i see speed increase from 1.2MB/s to 3MB/s (2.5 times), i see much higher speed increase on a slower connection like from 120KB/s to 1.2MB/s (10 times), maybe some kind of bottleneck on their end, in principle it should be proportional.
what speed increase do you see with ssl comparing to non-ssl connection on a single download headers task?
'sslreader.eweka.nl', poort 563 you need to check SSL.
does it work with them?
i don't have account, i just checked it accidentally with openssl.exe, it shows zlib compression enabled.
it is also possible they are resellers of some other usenet service which i've randomly tested, i don't know them really.
you should see header speed increase like 2.5 times, with UNS i see speed increase from 1.2MB/s to 3MB/s (2.5 times), i see much higher speed increase on a slower connection like from 120KB/s to 1.2MB/s (10 times), maybe some kind of bottleneck on their end, in principle it should be proportional.
what speed increase do you see with ssl comparing to non-ssl connection on a single download headers task?
it works!
I just put it to the test.
I use SSL connection with tweaknews server (included free in the tweakdsl provider subscription).
I header from several big groups and downloading a dvd at the same time.
And the download speed is very much exceeding what was normally the maximum speed.
Nice invention those compressed headers.
I guess that if it would not work, the download speed would be normal. Now it is sometimes 3 times as fast.
for the exact test you need some external bandwidth limiter.
then limit UE to 50KB/s (but from outside not from properties->tasks).
then observe what average bandwidth it shows on headers.
say if it is 500KB/s the ratio is 10.
then say, if without zlib compression you get 2MB/s with zlib compression it should be 20MB/s. the problem is some kind of bottleneck on the server side, maybe they are trying to balance the CPU load by limiting the bandwidth fed into zlib enabled connection, as they add more CPU power they will be increasing the bandwidth so you will observe higher actual speed as well. the maximum gain can be calculated by limiting bandwidth fed into UE so we won't hit their bandwidth limit fed into zlib. i estimate it is 10 or more, i didn't do the exact tests, if you have some external bandwidth limiter you could try.
then limit UE to 50KB/s (but from outside not from properties->tasks).
then observe what average bandwidth it shows on headers.
say if it is 500KB/s the ratio is 10.
then say, if without zlib compression you get 2MB/s with zlib compression it should be 20MB/s. the problem is some kind of bottleneck on the server side, maybe they are trying to balance the CPU load by limiting the bandwidth fed into zlib enabled connection, as they add more CPU power they will be increasing the bandwidth so you will observe higher actual speed as well. the maximum gain can be calculated by limiting bandwidth fed into UE so we won't hit their bandwidth limit fed into zlib. i estimate it is 10 or more, i didn't do the exact tests, if you have some external bandwidth limiter you could try.
at low downloadspeeds (i set the limit with the hardware router) i get a higher ratio: 5-10 of the headerdownloadspeed versus the maximum (it is however quite going up and down, so very changing in the time).
And it looks to decrease in ratio at higher speeds. Anyway, the headerdownload is quite low if i for example download headers from 4 newsgroups at the same time. Let say it is 200-300 KB/sec, while during downloadin dvd-s and such it is at least 1.5 MB/sec. But not really a constant speed (fast changing speeds).
So maybe they are playing around at the serverside. I thought it used to be higher some days ago. Could be a temporary server inbalance (many people downloading on the sunday).
(there is a yellow lock at the server icon, so it should be enabled).
And it looks to decrease in ratio at higher speeds. Anyway, the headerdownload is quite low if i for example download headers from 4 newsgroups at the same time. Let say it is 200-300 KB/sec, while during downloadin dvd-s and such it is at least 1.5 MB/sec. But not really a constant speed (fast changing speeds).
So maybe they are playing around at the serverside. I thought it used to be higher some days ago. Could be a temporary server inbalance (many people downloading on the sunday).
(there is a yellow lock at the server icon, so it should be enabled).
now i know
Now i know the reason:
The slow headers download appears when SSL is checked with port 563. And then i see a yellow lock (so slib).
When i change to port 119 without SSL i get the higher download speed. But it is the maximum download speed of the isp, and indeed the yellow lock is not there. So maybe something special with the server?
The normal downloadspeed of dvd-s an such does not matter if i use SSL or normal mode. Both at the max speed.
The difference is only with headers.
The slow headers download appears when SSL is checked with port 563. And then i see a yellow lock (so slib).
When i change to port 119 without SSL i get the higher download speed. But it is the maximum download speed of the isp, and indeed the yellow lock is not there. So maybe something special with the server?
The normal downloadspeed of dvd-s an such does not matter if i use SSL or normal mode. Both at the max speed.
The difference is only with headers.