Re: Enabling Deflate compression for DSL connections

[Alexander Konovalenko <alexkon gmail com>]

On Wed, Aug 4, 2010, Dan Williams <dcbw redhat com> wrote:
>
> Looks like NM forces it to nodeflate internally for some reason.  That
> code has been there since the beginning of PPPoE support I believe.  I
> don't really have a problem making NM respect the user setting for
> deflate, but I'm a bit concerned about whether this will introduce
> regressions if for some reason the option negotiation doesn't go right.
> However, are you able to test out a patch to see if deflate actually
> works with your provider?

Unfortunately it looks like my current ISP doesn't support Deflate
compression. I configured and ran pppd directly (using pon) both with
nodeflate and without nodeflate (and verified the actual options using
the dump option). I couldn't spot any differences neither in the logs
(pppd debug enabled) nor using pppstats. Here is pppstats output for
the deflate-enabled pppd run after downloading a large text file
without HTTP compression:

$ pppstats; pppstats -r; pppstats -z
      IN   PACK VJCOMP  VJUNC  VJERR  |      OUT   PACK VJCOMP  VJUNC NON-VJ
 8331712   5977      0      0      0  |   267000   2815      0      0   2815
      IN   PACK VJCOMP  RATIO  UBYTE  |      OUT   PACK VJCOMP  RATIO  UBYTE
 8331712   5977      0   1.00      0  |   267000   2815      0   1.00      0
IN:  COMPRESSED  INCOMPRESSIBLE   COMP | OUT: COMPRESSED  INCOMPRESSIBLE   COMP
    BYTE   PACK     BYTE   PACK  RATIO |     BYTE   PACK     BYTE   PACK  RATIO
       0      0        0      0   0.00 |        0      0        0      0   0.00

But I don't really know how the logs are supposed to look when the
peer doesn't support Deflate compression and we do. It's possible that
I misunderstand something here.

So currently I doubt I could find any regressions even if they
actually can happen. We should probably find some ISP which supports
Deflate compression and get a user of that provider test the patch,
too.

Would it be possible to gray out the "Allow Deflate data compression"
option in the UI to make the UI consistent with the actual behavior
and prevent possible confusion?

I filed a bug about this issue:
https://bugzilla.gnome.org/show_bug.cgi?id=626010

Thanks for your help!

 -- Alexander