Re: does anyone care about dialup
Please don't break threads (reply to your own posts instead of creating
new ones).
Please *do* include a subject.
On 10/05/12 09:51, Paul Zimmerman wrote:
> Miles Bader <miles@gnu.org> writes:
>
>> It may also be a problem with your service provider -- I had a
>> problem (back when I still used PPP) where the connection was
>> getting dropped mysteriously, and [after much frustration trying to
>> figure out what was happening] it turned out my provider didn't
>> support TCP header compression; turning off that feature in PPP
>> made everything work.
>
>> Apparently windows PPP clients didn't use header compression, so
>> they didn't consider it an issue ... -miles
They can, they don't by default.
And ISPs not supporting it is common.
<snipped>
> When
> pppd starts, it tries to negotiate the compression and this is
> accepted.
By default it's enabled.
It's not "accepted" until the ISP sends back a compressed packet - which
you'll find is not happening, hence the dropped connections.
Disable Van Jacobson compression in /etc/options.
By default most ISPs don't support field compression either - it's
disabled by default in Linux.
> So it is enabled.
Nope...
> A few minutes later the connection simply
> stops working with an error message "Lost compression sync" in the
> log.
Correct
> So it is enabled, but the local system cannot keep track of it
> for some reason.
If you sniff the connection you'll see your system asking for compressed
headers, and not getting them. My ISP does the same thing with my dialup
connection
That is either pppd itself or the kernel driver for
> serial connections. Disable "Van Jacobson" compression ("-novj" on
> the command line or edit the config file) and the problem goes away.
That's the problem described above - used to be that all ISP's enabled
compression for dialup, then broadband came along and compression became
rare. So often the -novj is required in /etc/ppp/option (MS doesn't use
it by default).
> What makes it so annoying is that it's sixteen years old. No one has
> bothered to fix this in over a decade?
The problem is at the ISP end - it's a wetware problem, not one that can
be fixed in the code ;-p
There is another problem with sl-modem that causes a "no carrier"
problem - that's fixed with the init I posted previously.
If you can connect with any operating system then you should be able to
connect with Debian - ppp is *not* broken, but many ISPs are.
Sniffing a working connection will solve any problems that can't be
solved by posting:-
;the ISP you're having problems with
;your ppp string
Kind regards
--
Iceweasel/Firefox/Chrome/Chromium/Iceape/IE extensions for finding
answers to questions about Debian:-
https://addons.mozilla.org/en-US/firefox/collections/Scott_Ferguson/debian/
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