[Asterisk-Users] giving up on x100p in Australia

[Rich Adamson]

> OK, I've spent way more time than I wanted to on getting
> an x100p clone to work in Australia. I'm happy to consider
> other (more functional) options.
>  
> Does anyone have an opinion on both the Sipura 3000 and
> other Digium cards (like the TDM400P)?
>  
> I need something that works with no much fuzz. I know the
> Sipura 3000 is cheaper the the TDM400P card.
>  
> All I need is to channel my POTS line into Asterisk. Nothing else!
> And I only have one line!

The spa3k works just fine but it also has a few little quirks that
may require you to devote some time to resolve. For example, it has
a very large number of configurable options that allow you to do
just about anything that you'd like, but the documentation on how
to use some of the config options aren't very clear to someone that
does not have extensive experience with the product.

I also experience some small amount of what I believe is "talk off"
where the spa3k intermitantly reacts to speech. It has not dropped
the call or anything, but once in awhile will generate dtmf tones
during a conversation as though it detected fax tones or something
like that. It also seems to flip-flop between full-duplex and half-
duplex audio occasionally. It seems female voices tend to be more 
objectionable then male voices in some cases.  (I've played with 
two different spa's, about four different firmware versions, and 
have seen the same issues with each. But, maybe I'm being a little 
hyper-critical of voice quality issues.)  Support for the spa
products is basically limited to user-lists unless you're large 
enough to be considered a reseller of their products. They too are
very secretive about existing problems.

If you've watched the list for the last several months, you've 
probably noticed the TDM card has some issues as well. The most
disturbing is the card goes out to lunch about every two weeks, which
has required users to stop asterisk and reload the TDM drivers. Not
everyone with the TDM card experience this problem, but those of us
that do, have had the problem since the card originally came out.
Digium is supposedly working at diagnosing/resolving the problem, but
they appear to be highly secretive of that effort. It certainly does
not help that the problem is so infrequent, making it extremely
difficult for _anyone_ to try to diagnose the problem. (I've made 
some modifications to my TDM card to help diagnose/resolve the issue, 
but its way too early to tell if those mod's have actually impacted 
the problem.)

The TDM card and the digium-sold x100p card use the same basic code
and zaptel drivers, etc, so whatever issues (eg, echo cancellation)
one might experience with the x100p aren't any better with the TDM
card. (I swapped two x100p cards for a TDM card with four fxo pstn
lines attached, and as of right now, it works fairly well except 
for the intermitant two-week failures.)

I might also add that several of the digium cards have an issue with
recording & playing back voicemail messages. For whatever reason, 
there is a 10db loss in transmission levels when one attempts to
play back voicemail messages via the pstn network (bug #2023). That
bug has been around for about six/seven months and has never been
addressed. The 10db loss has been measured (very professionally)
but everyone at digium refuses to believe its a bug. Regardless of
what its called, the 10db loss makes it almost impossible to listen
to voicemails remotely unless you're in a very very very quiet room.
Multiple * implementors have complained about this problem, so its
not a simple parameter/configuration adjustment, etc.

The voicemail playback volume is significantly worse for those
asterisk systems that are further away from the Central Office.
That is due to the pstn plant loss (unavoidable) on top of the
10db loss. So, if your asterisk box were 18,000 feet from the CO
(as an example only), one would incure about a 7db plant loss in
recording the voicemail, the 10db loss noted in bug 2023, plus
an additional 7db loss listening to that voicemail via the pstn.
That's a total of 24db loss, which makes listening extremely
difficult. (If the asterisk machine were colocated in the Central
Office, listening to voicemails would only incure the 10db bug,
which does not have the same user impact as the 24db loss. So,
those folks that are closer to the CO don't complain about this
particular bug.) The 10db loss has been noted by users of the
TDM card, T1 cards, etc, from digium; it is never seen when using
other vendor's pstn gateways.

The x100p (and clones) tend to be just "okay" for low volume soho
use, but as you've already experienced, the majority of those cards
were designed/targeted to the US market back when WinModems were
popular. Some of the clone cards do have chip sets for the non-
US market, but the people selling them won't tell you which chip
set is on their for-sale cards. Therefore, implementing a clone
in non-US (eg, non-600-ohm pstn networks) is a crap-shoot at best.