Speed issue: VPN vs Remote Desktop

[DerekG]

Hello - I've established both a Remote Desktop connection
as well as a VPN connection between two XP computers over
the Internet. Both connections work, but the speed of the
VPN connection pales in comparison to the Remote Desktop
connection, to the point where the VPN is useless for
copying files or running the programs I need to run. Does
anyone have any ideas as to what could be causing VPN to
be so slow?

Thanks,
Derek

 

[Lanwench [MVP - Exchange]]

Because RD is just a terminal, showing you 'pictures' of what you're doing -
you aren't dragging files across a slow network connection. RD is often the
better choice for running resource-heavy/critical applications like a
database, accounting software, etc. The disadvantage is that you can't take
data with you - it's only accessible while connected to it over the
network/Internet.

VPN is useful for other things ....such as syncing an Exchange mailbox to an
offline folder in Outlook, syncing local files to a server share, etc.

 

[Joe T]

The reason is that remote desktop is what I've wanted from
microsoft since the invention of x windows!

Remote Desktop is very much like x windows, whereby actual
windows objects are transmitted and then recreated remotely
(so that on the client side, you are using real windows
objects, not pictures of them). This is very cool and very
efficient.

VPN and software like that work by transmitting deltas of
screen bitmaps - at least that is my assumption. So the
server asks it self "what has changed since the last time
the client requested a snapshot?" Then the server creates
one or more bitmaps and sends them over - very slow and
inefficient.

--Joe

 

[Lanwench [MVP - Exchange]]

.....actually, it depends what you're accessing over VPN - VPN is a means of
accessing a remote network as though you were connected to it, meaning you
map drives, open files, etc....it can be slow. It does give your computer a
real network connection to the host computer(s), so you can open Word on
your desktop and open a Word doc on a remote drive. It has its uses. It
isn't very good if you're opening a large database or something, as it will
be slow and if the connection is interrupted, you may lose data.

.... And you really are just looking at 'pictures' on a terminal with RD.
They don't exist on your computer; just in the terminal window. That's why
it's a lot faster.

Many people use VPN in conjunction with RD/Terminal Services - to access
remote desktop more securely than just poking open 3389 in the
router/firewall.

 

[Bill Sanderson]

Actually, copying a file via the VPN connection should be FASTER than
copying it over a pure RD connection, according to some folks here who did
comparisons, and my own experience.

Lanwench has given the story about why RDP is faster for doing
screen/keyboard/mouse stuff, but moving mass amounts of data between the two
machines should be faster via a straight network connection across the VPN.

 

[Lanwench [MVP - Exchange]]

Ayuh.

Actually, copying a file via the VPN connection should be FASTER than
copying it over a pure RD connection, according to some folks here
who did comparisons, and my own experience.

Lanwench has given the story about why RDP is faster for doing
screen/keyboard/mouse stuff, but moving mass amounts of data between
the two machines should be faster via a straight network connection
across the VPN.

 

[Bill Sanderson]

I think your pictures are confused.

VPN is straight networking--i.e. it is just a pipe, like Ethernet, but with
the added overhead, both physical (extra bytes in each packet) and
processor-load (encryption/decryption).

RD DOES use deltas of bitmaps--as efficiently as it can.

Since I'm reaching limits of (my own) technical accuracy here, let me see if
I can get you some references:

RDP
http://www.microsoft.com/technet/tr...echnol/win2kts/evaluate/featfunc/rdpfperf.asp

PPTP VPN
http://www.microsoft.com/ntserver/ProductInfo/faqs/PPTPfaq.asp