Re: [EXIM] Exim and ISDN (was: Exim is too fast?)

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Author: Lee Bradshaw
Date:  
To: exim-users
Subject: Re: [EXIM] Exim and ISDN (was: Exim is too fast?)
On Tue, Nov 24, 1998 at 02:57:27PM -0500, Jeff Mcadams wrote:
> Thus spake Mark Seuffert
>
> >I guess my last question has been stupid (?) or none of you is using an
> >ISDN connection, right? I still have the problem that big mails block the
> >connection for several minutes and would appreciate any experience/ideas.
>
> >I think it should be possible to connect an small intranet via ISDN,
> >actually a lot of customers do, because it's much cheaper. It's possible
> >to slow down the local proxy (squid)... but what about the MTA? No other
> >service makes so much traffic, that I would wish to limit the resource
> >consumption. Thx a lot for help.
>
> You probably *really* should be doing this at the router level rather
> than at the application level. Depending on the routers/NAS'es that
> you're using, some of them have support for this type of functionality
> (traffic-shaping is what it's commonly called). I know newer versions of
> Cisco's IOS has the ability to do some of this, as for other vendor
> implementations...I don't know for sure.
>
> I'm not aware of any config at the application level (exim) that can
> control this well...you could probably limit it down so that only one
> delivery is going to that particular host at a time, but even a single
> delivery of a large file could overwhelm an ISDN line (as you're
> probably aware).
>
> If you want to do this on a larger level, where the level can support
> the purchase of hardware such as these, you can look at packateer (sp?)
> and xedia as both have boxes (packateer functions as a bridge, xedia can
> function either as a bridge or a router) that will do traffic shaping on
> a large scale and for a large number of classifications. Xedia, I know,
> can handle at least up to Fast Ethernet speeds (maybe higher?), but is
> certainly not cost effective to deploy one of these boxes for a single
> ISDN line!


I don't know what OS you're using, but linux 2.0.36 has basic traffic shaping
support. The 2.1.X and 2.2 (when it's out) supposedly have more advanced
traffic shaping. I don't know the definition of basic or advanced, but it
might be worth looking into if you use linux.

-- 
Lee Bradshaw                 lee@??? (preferred)
Alantro Communications       lee@???


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