[lug] PoPToP Performance

Wed Feb 18 21:45:18 MST 2004

George Sexton wrote:
> 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.

That's partly because you transmitted one large file.  I think you will 
find a much larger difference if you try 19MB worth of 8kb files.

I try to avoid VPNs wherever possible both because of both performance 
and security.  For example, I have clients set up with TortoiseSVN to 
connect securely to a Subversion repository to replace network shares. 
They don't even use network shares on the LAN anymore.

> 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
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>>
> 
> 
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