[lug] PoPToP Performance

[George Sexton]

SMB is really not the best performing protocol over limited bandwidth
connections. In general, using file based database systems over a VPN is
not going to perform well. Client/Server applications can perform
reasonably in this kind of environment.

Another issue is that upstream speeds on cable modems are dramatically
less than downstream. My upload rate is about 32KB/s. My download rate
is around 210 KB/s.

It looks to me like the largest share of your perceived latency is
caused by the asymmetrical nature. If you look at your upload rate with
SMB versus SCP, the difference is only something like 30%, which while
not wondrous, isn't extremely bad.

George Sexton
MH Software, Inc.
Home of Connect Daily Web Calendar Software
http://www.mhsoftware.com/connectdaily.htm
Voice: 303 438 9585

-----Original Message-----
From: lug-bounces at lug.boulder.co.us
[mailto:lug-bounces at lug.boulder.co.us] On Behalf Of Ryan Wheaton
Sent: Wednesday, February 18, 2004 11:16 AM
To: Boulder (Colorado) Linux Users Group -- General Mailing List
Subject: Re: [lug] PoPToP Performance


Hey guys.

I did some testing last night, comparing file transfer speeds using 
different protocols, with and without the VPN.  I used the same 19.1 MB 
file do do each transfer.  Here's what I found:

With the VPN:

UPLOADING 	|	to windows file share, took about 13 minutes.
			|	using scp (secure copy) to a linux
server, took about 10 minutes

DOWNLOADING	|	Using a browser (HTTP), got about 180Kb/sec
transfer 
rate, took about 2 min 15 sec
				|	using wget (HTTP), got about
135.80Kb/sec transfer rate, took 2 
min 50 sec
				|	from windows file share (SMB),
took about 9 minutes
				|	using scp from a linux server,
took 2 min 13 sec

With out VPN:

UPLOADING	|	using scp to a linux server, took about 10
minutes

DOWNLOADING	|	using wget (HTTP) got 171Kb/s, took about 2 min
30 sec
				|	using a browser (HTTP) got 171.9
Kb/s took 1 min 53 sec
				|	using scp took 1 min 55 sec


and they seem to be comparable.  My biggest problem, and the thing that 
affects my users the most, is the sloooooow copy speed both up and down 
copying to windows file shares.  Any suggestions on how I can track 
down the bottleneck here or to improve performance?  I've got the WINS 
server set in my options.pptpd file...  should I remove this?  Is there 
any special routing that I can set up that will improve copy speeds?

thanks again for all the help before (and presently).

-rtw

On Monday, Feb 16, 2004, at 12:42 America/Denver, Calvin Dodge wrote:

> On Mon, Feb 16, 2004 at 09:37:10AM -0700, Ryan Wheaton wrote:
>>
>> I've finally gotten my PoPToP VPN server to accept connections
>> correctly, and all seems to be dandy, but it is unbelievably slow.  I
>> couldn't get exact Mb/s times, but when I tried to copy the CentOS 
>> ISOs
>> (about 1.8Gb) to a file share over the VPN, it was going to take
about
>> 23 hours.  I have a cable modem at home, so i'd expect that 
>> performance
>
> You're doing this from Windows? That sounds a little slow, but not too

> slow.
>
> I have a friend with a cable modem (150 KBps) in Boulder. He also uses

> a VPN connection to the office server (Linux with PPTP).
>
> We timed some 5 megabyte copy operations. Ftp over the VPN runs around
> 135-140 KBps, while copying from Windows runs at around 50 KBps. 
> Database
> access is painful - Goldmine takes 20 minutes to open.  I suspect the
> Windows copy (and database) issue is due to latency - there are more 
> packets going back and forth, with a delay of .1-.2 second for each 
> round trip.
>
> Calvin
>
> -- 
> Calvin Dodge
> Certified Linux Bigot (tm)
> http://www.caldodge.fpcc.net
> _______________________________________________
> Web Page:  http://lug.boulder.co.us
> Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
>

_______________________________________________
Web Page:  http://lug.boulder.co.us
Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
Join us on IRC: lug.boulder.co.us port=6667 channel=#colug