Linux a worse router than Windows?

No, it can't be, I know. But I need some help with configuration.

I am currently in a locale where only dialup is available. Until
recently, I had been using a speedy (3 GHz or so) Windows XP laptop as
the dialup machine. Internet Connection Sharing was enabled, and a
Linksys router was attached to that. I was using my Linux notebook via
a wireless connection to the router, and -- here's the thing -- I also
had an IP phone modem hooked up to the router.

I was able to make calls using the IP phone, and although there was
generally a bit of delay, and occasional distortion, overall the
quality was amazing. I am in a country where the telephone
infrastructure was only recently installed, and I'm guessing that for
that reason I have got the best 56k connection I've ever seen in my
life.

However, I recently had to remove the Windows machine from the
equation. And there the trouble began. I am able to connect via
dialup, using the slmodemd package for Alsa (since I have one of those
pseudo-modems, "WinModems" or whatever they call them). I achieve
connection speeds just as good as what I got with the previous
configuration. As near as I can tell, the performance for web browsing
seems to be the same too.

But the IP phone is now totally useless. Less than 10% of either side
of a conversation gets through to the other.

I have tried removing the router from the picture. The IP phone is now
just directly plugged in to my Ethernet port on my Linux notebook. No
good, same story.

I am not a networking expert in any sense of the word, so I have used
Firestarter to configure the firewall and routing. I have tried both
DHCP and a static IP address for the IP phone box.

I would really appreciate any guidance as to what I might do to
diagnose this situation, and what it could be that's caused such a
performance degradation between these two scenarios. I always assume
that everything is infinitely more configurable with Linux, and that
there's got to be a way to get things back to at least as good as they
were with the previous setup. But I don't know where to start.

Help! Please! Thanks!

Noel

nd some help with configuration.
>
> I am currently in a locale where only dialup is available. Until
> recently, I had been using a speedy (3 GHz or so) Windows XP laptop as
> the dialup machine. Internet Connection Sharing was enabled, and a
> Linksys router was attached to that. I was using my Linux notebook via
> a wireless connection to the router, and -- here's the thing -- I also
> had an IP phone modem hooked up to the router.
>
> I was able to make calls using the IP phone, and although there was
> generally a bit of delay, and occasional distortion, overall the
> quality was amazing. I am in a country where the telephone
> infrastructure was only recently installed, and I'm guessing that for
> that reason I have got the best 56k connection I've ever seen in my
> life.
>

> pseudo-modems, "WinModems" or whatever they call them). I achieve
> connection speeds just as good as what I got with the previous
> configuration. As near as I can tell, the performance for web browsing
> seems to be the same too.
>
> But the IP phone is now totally useless. Less than 10% of either side
> of a conversation gets through to the other.
>

This is just a try I suggest, I never had this problem: maybe try to
disable ppp compression ( edit /etc/ppp/options or whatever and check
there is no compression option enabled by default ). Maybe this is the
cause of the latency which makes VOIP unusable.

Thanks -- I checked, but all PPP is already disabled.

Is it possible that Windows XP has some special automatic configuration
for dialup connections that makes it work better? Just now I tried this
with a borrowed Windows 2000 machine, and got similarly bad results. So
it seems that XP has a leg up on everybody for making best use of a
dialup connection, or at least for the way it shares it. But what could
that be? Please help, I'm a networking nincompoop, but I need my IP
phone!

I mean all PPP compression is disabled.

(E-Mail Removed) wrote:
> Thanks -- I checked, but all PPP is already disabled.
>
> Is it possible that Windows XP has some special automatic configuration
> for dialup connections that makes it work better? Just now I tried this
> with a borrowed Windows 2000 machine, and got similarly bad results. So
> it seems that XP has a leg up on everybody for making best use of a
> dialup connection, or at least for the way it shares it. But what could
> that be? Please help, I'm a networking nincompoop, but I need my IP
> phone!
>

I would suspect the xp machine was just a faster machine

Remember it's a "WINMODEM" not a real modem .. it's software driven

may just be better/newer drivers in Xp

Your trying to compare different cpu's with different hardware and
equate it to a operating system problem

Which by the way Your using 3 different operating systems for comparison.

Maybe you need to configure QoS, as the VoIP traffic could get drowned
out otherwise.
AFAIK Windows XP has this built-in, but your linux distro may not.
You could use iptables (marking packets) then tc to schedule them.

Good luck!
Regards,
Tobias Skytte

On Thu, 08 Sep 2005 12:42:52 -0700, noelbush wrote:

> No, it can't be, I know. But I need some help with configuration.
>
> I am currently in a locale where only dialup is available. Until
>
<snip>
>
I don't know, but I'd say you are never going to get VOIP to work with 56k
speed. That is, whether or not it is "the best 56k" connection, it is
still 56k (down), 33k (up).

VOIP works with broadband. The ratios of typical DSL vs. dialup are as
follows:

Direction DSL 56k Dialup Ratio
Upload 750 33 22.7
Download 1500 56 26.7


The line speed difference is the biggest factor, not linux as the router.
There is no magic rabbit you can pull out your hat to overcome this
limitation, but see below.

But you say that it was working before and now need to add the
complication of using a sound card for a modem in another country. I
found this page, http://ronispc.chem.mcgill.ca/ronis/misc/zv5240ca.html

which makes reference to the country settings and CVS for the slmodem
package. Good luck.

Your situation sounds quite complicated. I won't say what is
and is not possible for /* you */ because it seems /* you */ may have
already overcome some major obstacles. For example, how did you get
the phone to work at all by just connecting it to /* any */ free ethernet
port (phone directly to laptop)?

Here is an idea for a simpler platform for your IP phone.
Get an external 56k modem and an ethernet router with fallback to dialup,
such as the D-Link 804HV. From there you should be able to do more tests
which show if VOIP works at those data rates. Of course, there is the
negative factor of so many dedicated boxes.

|
|
+---POTS---+
|
+--<USR 56k modem>
|
|
<DLINK 804HV>
|
|
(ethernet)
|
-----+-----
| |
IP Phone other DHCP clients

(E-Mail Removed) wrote:
> No, it can't be, I know. But I need some help with configuration.
>
> I am currently in a locale where only dialup is available. Until
> recently, I had been using a speedy (3 GHz or so) Windows XP laptop as
> the dialup machine. Internet Connection Sharing was enabled, and a
> Linksys router was attached to that. I was using my Linux notebook via
> a wireless connection to the router, and -- here's the thing -- I also
> had an IP phone modem hooked up to the router.
>
> I was able to make calls using the IP phone, and although there was
> generally a bit of delay, and occasional distortion, overall the
> quality was amazing. I am in a country where the telephone
> infrastructure was only recently installed, and I'm guessing that for
> that reason I have got the best 56k connection I've ever seen in my
> life.
>
> However, I recently had to remove the Windows machine from the
> equation. And there the trouble began. I am able to connect via
> dialup, using the slmodemd package for Alsa (since I have one of those
> pseudo-modems, "WinModems" or whatever they call them). I achieve
> connection speeds just as good as what I got with the previous
> configuration. As near as I can tell, the performance for web browsing
> seems to be the same too.
>
> But the IP phone is now totally useless. Less than 10% of either side
> of a conversation gets through to the other.
>
> I have tried removing the router from the picture. The IP phone is now
> just directly plugged in to my Ethernet port on my Linux notebook. No
> good, same story.
>
> I am not a networking expert in any sense of the word, so I have used
> Firestarter to configure the firewall and routing. I have tried both
> DHCP and a static IP address for the IP phone box.
>
> I would really appreciate any guidance as to what I might do to
> diagnose this situation, and what it could be that's caused such a
> performance degradation between these two scenarios. I always assume
> that everything is infinitely more configurable with Linux, and that
> there's got to be a way to get things back to at least as good as they
> were with the previous setup. But I don't know where to start.
>
> Help! Please! Thanks!
>
> Noel
>
I think you are going to find that Linux does not do a good job of running
"WINMODEMS" so you might look for a real modem, one with serial port jumpers or
better yet an external modem that plugs into your serial port.


--
Leo in Canada:
They said "everyone uses microsoft" and so like the lemmings they marched into
the sea.
< running Linux >

Leo (Bing) Whiteway wrote:

> I think you are going to find that Linux does not do a good job of running
> "WINMODEMS" so you might look for a real modem, one with serial port
> jumpers or better yet an external modem that plugs into your serial port.
>
>
>

Actually, it can run them quite well. There's one in my ThinkPad, that
works very well with Linux. However, not all Winmodems have Linux support.

That said, I'd still prefer an external modem regardless.

It does seem like, from what you and others have said, that this must
be the crux of the matter. As I said, I'm getting perfectly acceptable
performance, just as before, with all other use of the Internet through
my new setup. I anticipated problems with using a winmodem instead of a
"real" one, or with the different country issues, but I think the fact
that all other net use is working fine tends to rule all that out,
right?

I tried looking around for some guidance on setting up QoS for VoIP on
Linux, but it looks like this is something that is still in the
"read-up-on-it-for-a-week-and-recompile-your-kernel-ten-times" stage.
Or can you recommend a simple step-by-step resource? I'm no networking
guru, not by a long shot, so unless this is something that I can have
some hope of getting to work in an hour or so of fiddling around, it
seems like I'm out of luck.