Re: [hylafax-users] Remote hangs up after ANSWER

["Sjon Wijnolst" <webmaster@salisbury.nl>]

[blablabla] read the rest of the mails for the problem
> >>
> >> Tried using Class 1 ?
> >>
> >> Lee.
> >>
> >
> >No, that could be an option. But, what does it mean for sending and
> >receiving faxes when I use Class 1 instead of Class 2? Are there any
> >disadvantages?
>
> Simplified... Class 1 is fax protocol that is mostly run by
> the software.
> Class 2 is fax protocol that is mostly run by the hardware (firmware).
> That's the basics of the differences.
>
> In practice... Class 1 tends to be easier for us to work with
> because we
> can see, edit, and review most of the code which runs the protocol -
> because it's embedded into HylaFAX.  In the past, people have
> been worried
> about using Class 1 because of CPU usage (especially when
> running several
> modems in one system) affecting the critical timing that fax protocol
> requires.
>
> Frankly, unless they were running 286 or 8088/8086 systems (and even
> then...) or the system was weak and normally using +80% CPU,
> I don't think
> this is a valid concern.  So, in the past, when people have
> felt like Class
> 1 was less reliable than Class 2 because of timing problems -
> well, I think
> that their fingers were pointing at the nature of the Class 1 protocol
> rather than where it should have been pointing: their
> implementation of the
> Class 1 protocol.
>
> So, these days Class 1 in HylaFAX tends to be much more
> reliable than Class
> 2/2.0.  Why?  Because we've worked out most of the bugs that
> so plagued
> such doomsayers before.  If you find a flaw with Class 2/2.0 protocol,
> chances are good that HylaFAX can't fix it - because the code
> to fix is
> embedded inside the chips on your modem.  So in order to make
> Class 2 work
> on all modems perfectly, HylaFAX has to make its Class 2 code full of
> workarounds and fixes for faulty firmware - not a fun job,
> and for what
> when we can simply just switch to Class 1?  If we find a
> Class 1 bug - in
> most cases we just have to fix the code that's causing the
> problem.  You
> can see that the latter option is much more friendly.
>
> But - there have been instances where I've found that certain
> modems cannot
> CONNECT with certain other modems or fax machines after ATA
> or ATDT when
> using one fax Class or another.  So, that's why in your case
> I recommended
> using Class 1 to test.  If it still doesn't connect, then we
> try something
> else - like disabling adaptive answer.
>
> Lee.
>

That's very clear. We've had no more problems with other people and someone
else from the same company can fax to us but I don't know if they use the
same fax. I'll try to find that out. So far, Class 2 hasn't done any harm.

Your explanation is very clear and I can agree there's no argument against
using Class 1 and using the CPU a bit more. If we continue to run into
trouble, I'll try that.

Adaptive answer is already turned of since the system only receives faxes -
it's easier, less chance on errors and the call is answered faster.

Thanks, Sjon.



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