Re: PPP with "IP compression" issue?
- From: "Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam DOT com>
- Date: Thu, 3 Apr 2008 13:32:02 -0700
I can't tell you if it's true or not, but I can say that it appears to me
that, with Platform Builder and the Shared Source, you should be able to
trace through the configuration of the connection and the negotiation of the
options with the server to verify where the problem is, if any. The code in
connmc seems fine to me; I think that the right RASENTRY options are being
set based on the dialog checkbox settings.
If you're convinced that it's broken, you could just use one of your
Platform Builder support incidents to report it as a bug and see what MS
says...
Paul T.
"Mai Kee Reiss" <MaiK_NOSPAM_reiss@xxxxxxxx> wrote in message
news:MPG.225f573f1c6c05459896b7@xxxxxxxxxxxx
Can anybody please confirm or deny the following bug in PPP.dll?
BUG:
When creating a new Phonebook Entry for an outgoing modem connection,
by default both parameters
"IP software compression" and
"IP header compression"
are enabled/checked (in TCP/IP settings) in connection properties. But
disabling/uncheking it, seems to have NO EFFECT.
DETAILS:
The check boxes are empty, even after warm booting the device, so
registry is okay.
But if I make an outgoing call to a Win 2003 server, which is running
"RAS and Routing" for multiple simultaneous incomming lines, the
communication is always compressed from the Embedded device's UART on
(not talking about V.42bis modem compression!) from the point PPP
negotiated the IP and DNS entries.
Inspected with a PPP tracer (used "SerialView" from Klos Inc.), we see
that the WinCE device always starts wit an PPP/LCP protocol Request for
both "Van Jacobsen" and "Protocol and Data Field" compresion. Since W2K3
is able to handle that, both sides later negotiate MS PPC compression
via PPP/CCP protocol. I can also see all the other LCP / CCP stuff
uncompressed (as RFC 16xx requires), but from the 1st IP packet on, I
only get compressed packets.
- This problem was seen on several WinCE 4.20 versions (step by step
checked with all QFEs, released between 2003 and current) as well as on
several WinCE 5.00 (taking some spot samples between 2006 and current).
- This problem does _not_ occur on a large number of Internet Service
providers, because their Dial-In Router Pools don't support MS PPC or
don't support compresion at all. No one of them uses W2K or W2K3 servers
for modem dial-in, of course.
DRAWBACK:
We can't prevent devices to send data compressed over phone lines!
THOUGHTS:
One can think now: "okay, what problem comes from compression?
compression is always good for that crap slow lines!".
Hmmm... we always transmit ZIP files, so in the 1st degree, compression
gives us more CPU usage and more power consumption. Together with
running C#.NET Application, it sometimes run into CPU saturation. Odd!
And, some times more bugging, my PPP/IP tracer tool is not able to
decode MS PPC :-( If I want to debug some communication protocols in IP
or TCP level, I need this tool. But there is nothing compareable out in
the market that can capture IP from RS-232 lines (WinPCAP can't! on
RS232 and WinPCAP can't on RAS Server)
BTW:
does anybody know, how compression could be switched off at the W2K
side? This would not solve my problem at all, but I could at least
continue to use my PPP/IP analyzer ;-)
I would highly appreciate any helpful answer ...
--
Mai Kee Reiss
.
- References:
- PPP with "IP compression" issue?
- From: Mai Kee Reiss
- PPP with "IP compression" issue?
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