low link speed using VPNs

[rlebrun1]

I have read hundreds of articles on MS Knowledge Base
looking for a clue related to this topic but there is no
information about it. Also I have posted this question on
many Forums and I haven't received a workable solution
either. It is like no one knows anything about it.

I have been able to observe that MS Server 2003 (and W XP
too) creates virtual adapters (like modems or NICs that
are hidden: Device Manager > View > Show Hidden Devices).
Perhaps those logical adapters that the VPN connections
go thru have the link speed hard coded on it. It is just
a supposition because I can't find where to look for.

*******************************************************

I installed MS server 2003 and is working great, it is a
multihomed implementation with two 100 Mbps NICs (one for
the Internet link and the other for the LAN)...

I implemented RRAS and works great too, but...

I'm able to use VPNs, Routing, Remote Desktop,
Remote Control, File Sharing, etc. (almost any kind of
communication I can think of, and all of them across
Internet).

I have a broad band at the main office (512 kbps), and
another broad band at an overseas branch office (512
kbps too)... (both are 512 kbps)...

but RRAS assigns a bandwidth of 28.0 kbps to every RRAS
port (PPTP, L2PT, modem, etc.) I get connected to, which
intuitively is wrong due to the fact that both sides are
broad bands. The connection I get is terrible slow (28.0
kbps) even if I make just one connection...

*******************************************************

How can I do to get around and have RRAS making or
accepting a connection that takes full advantage of the
broadband, or in other words, to make a connection with
speed near the 512 kbps I have available in both sides,
at the main office and at the overseas branch office?

Is there any parameter or tweak (say the registry or
alike...) or any other procedure I can follow, so I could
change or fix the low link speed that the RRAS assumes?

 

[Michael Johnston [MSFT]]

The connection speed that is reported is just a interpretation of a string returned once the connection comes up. In the case
of modems, the negotiate string is returned and the OS just reports that speed. For VPN connections, it simply returns the
connection speed of the adapter the VPN connection is using. If you have a broadband connection and an ethernet adapter
that connects to the broadband connection, the OS will report the speed of the ethernet adapter. In your case, it would report
100Mbs. This isn't a governing limit. It will use whatever bandwidth the connection can physically handle. The connection
speed has little relevence. If you are seeing a low connection speed for something that should be going through the LAN
connection on the box, then I'd suspect there was a routing problem causing the connection to go out the modem connection
instead of the broadband connection.

For the details on the modem speed reported refer to 227695 Incorrect Modem Connection Speed Is Displayed
http://support.microsoft.com/?id=227695.


Thank you,
Mike Johnston
Microsoft Network Support
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[Mark Johnson \(317940\)]

Michael,

May I jump in here please in a way that might simplify some of the
discussion?

I'm encountering the same behavior as the previous visitor (rlebrun1),
except that my RRAS server is much more 'lean' in this respect. There is no
modem attached to the machine at all, and it is simply a single NIC
connected directly to the Internet (but behind a domain firewall) ---
therefore I expect that all traffic is piggy-backed on the IP of the server
itself.

However, when I look at taskmgr I see that the RRAS connection (which in my
case can only be via an ethernet), it's reporting 28.8 kbs, and frankly, i'm
certain that is the speed at which things are operating (a single Word file
of 150K takes about 15-20 seconds to upload).

Now it could be that I have things mis-configured, but that's another story.

Thanks for your time and help.

The connection speed that is reported is just a interpretation of a string

returned once the connection comes up. In the case

of modems, the negotiate string is returned and the OS just reports that

speed. For VPN connections, it simply returns the

connection speed of the adapter the VPN connection is using. If you have

a broadband connection and an ethernet adapter

that connects to the broadband connection, the OS will report the speed of

the ethernet adapter. In your case, it would report

100Mbs. This isn't a governing limit. It will use whatever bandwidth the

connection can physically handle. The connection

speed has little relevence. If you are seeing a low connection speed for

something that should be going through the LAN

connection on the box, then I'd suspect there was a routing problem

causing the connection to go out the modem connection

instead of the broadband connection.

For the details on the modem speed reported refer to 227695 Incorrect

Modem Connection Speed Is Displayed

http://support.microsoft.com/?id=227695.


Thank you,
Mike Johnston
Microsoft Network Support

rights. Use of included script samples are subject to the

terms specified at
http://www.microsoft.com/info/cpyright.htm

Note: For the benefit of the community-at-large, all responses to this

message are best directed to the newsgroup/thread

 

[rlebrun1]

Dear Mr. Mike,

I truly thank your interest in my request and at the same
time I'd like to make some extra comments:

According to what I have read so far, I understand that
the connection speed can be related somehow to the
following:

The OS takes from the handshake stage during the
authentication process some parameters to assume slow
connection speeds.

There are cases when DTE speed and DCE speed has
something to do with this issue.

If I open the RRAS GUI and I go to the Remote Access
Policies, and I edit the profile, I get the choice
of "Allow Access Only Through this Media NAS Port Type".
I went thru this making sure that only xDSL media devices
were allowed (the modems I'm using are for ADSL links -
fast and persistent links-, not for the regular ones used
for analog connections).

Ok. so far, so good.

The article you mention was one of the first ones I read,
and what I did, after reading that one in particular, was
to take out the modem that the box had from factory, then
I made a clean OS new installation (formating disks
included), seeking with this initiative to make sure that
the OS wasn't able to see any analog modem or anything
related to it from the very beginning. It was very
disappointing to see that the problem persisted after
doing all of that.

Now see two interesting things that I could observe:

First:
If I make a RAS connection, and then I open the Task
Manager and go to the Networking tab, I can see that
there is some activity in the RAS connection reporting a
link speed of 28 kbps.

Second:
If I make a Routing connection, and then I open the Task
Manager and go to the Networking tab, I can see that
there is something different happening. I still get the
RAS connection reporting a link speed of 28 kbps, but
there is no activity in that connection.
Also another connection shows up having activity on it, a
wan miniport PPP/SLIP connection reporting a 100 Mbps
link speed. When I saw this the first time, I thought
that the problem was solved somehow, but it didn't.

In every of the many tries I've made, I always take a
small file (4 Mb) and transfer it across the link. It
should take about a minute or so to be transferred using
a 512 kbps link. It doesn't, it takes about 20 minutes to
be transferred, which is ok for a 28 kbps analog modem
speed, but not for a broad band connection.

When I make the Routing connection and I get that
wonderful link speed of 100 Mbps that I mention above
and I transfer the small file (4 Mb), the graph reports
that the PPP/SLIP link is using only 0.11% of the link,
which in few words, is an analog modem speed of 28 kbps
(and the analog modem is not around, remember that I
reinstalled the OS without the analog modem being in the
box).

So, it doesn't matter which link speed the OS reports on
any GUI, the transfer of blocks of data is made close to
the slow and frustating rate of 28 kbps.

I final comment. This issue is so important to me because
I have the idea that if I can get the way to solve this
problem, then Frame-Relay will be history, and as you may
know, a broad band connection is a lot cheaper than a
Frame-Relay link, saving a lot of money by means of
making VPNs over Internet at a reasonable speed and with
the acceptable well known factor of 99.7% which is ok for
me.

I really hope you can see this comment and keep looking
for a clue where to look for.
Thanks again in advance,

 

[Mark Johnson \(317940\)]

I'm wondering whether I may have found something. I don't know whether
(e-mail address removed)'s situation is the same as mine, but I've been
testing/using this RRAS/VPN connection from my home computer through my
RoadRunner broadband connection to a Windows Server 2003 machine that's
directly connected to the Internet (in my case, alas, the server runs on a
10Mb hub!). Anyway, I was finding the same situation as his, and tried
testing a whole bunch of things.

After looking at all the possible adapters, etc., I wondered whether the
issue might be my connecting software here with Windows XP Professional. So
I tried tweaking various things and wondered whether the QoS software that's
built into Professional had something to so with things. So I simply
uninstalled it (knowing that it gets totally removed from the computer).
When I connected to my Windows Server 2003 RRAS the next time, I downloaded
a 17.9 megabyte file in 1 minute flat!!!

I'll try to get more certain about things soon, but with speeds like that,
I'm wondering whether I may well have found the culprit.