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Re: (ASCEND) MAX 2012: Bad X75 performance
In article <199801061125.MAA00633@brian.voerde.globvill.de> you wrote:
>we are in the process of shifting from a linux dialin server to a
>Max 5.0Ap36. Access via Modem and ISDN already works. What makes us
>worry is that async PPP via X75 shows a low throughput of approx. 3.5k/s.
You didn't say what kind of max you're using, I assume it's a 4000 oder
2000? Anyway, with those maxens and 5.0Ap36, X.75 should basically work.
At least it does here... We did see a few problems with earlier releases
(Ap11 & Ap27), but Ap36 & Ap38 are OK. A few of our customers still use X.75
and performance is good (>7Kbit/s).
The real *problem* with X.75, and yes, we also bought the max because it
supposedly works fine with this protocol, is not with performance.
In Germany, a frame length of 2048 is the default setting for most ISDN TA's
and CAPI's / port drivers. Too bad the max can't to 2048, it maxes :) out at
1532 due to internal protocol translations.
This turns into a major problem when your users start uploads, thus creating
packets the max chokes on.
The PPP connection will break immediately and the user will give you a call.
If you care for a piece of advice, *force* your users switch to HDLC/syncPPP
(PPP over ISDN), which is an RFC standard and works fine. According to my
experiences it's a lot easier to have the user change the protocol in
his/her setup than to make them look for a way to change the frame length.
Besides, the performance your customers get with HDLC/syncPPP (both throughput
and latency) is better, maybe that'll help convince them :)
>The support of this protocol was a major
>arguement when we chose between a Portmaster and the Max.
I think you'll be quite happy with the max, as soon as you dump X75 for
PPP connections.
--
Oliver J. Albrecht <oj@nexus.flensbone.net>
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