[VoIP] DP-compatible ATAs

[Steph Kerman]

Audiophile bah!  I'm talking about huge unpredictable gaps and drop outs 
intermittently for seconds at a time.  The connection quality is not 
something anyone paying would tolerate.  Even for free it's a nuisance 
to try to carry on a conversation.  At its best it's excellent.  At its 
worst, which is frequent and unpredictable, you just have to repeat 
yourself or wait until the hits go away.

Steph

ikjtel wrote:
> In Message-ID 45945B97.7050609 at jps.net, Steph Kerman
> wrote:
>
>   
>> [snip]  However the CNET calls I've made so far
>>     
> through Greg's 212 PSTN portal don't sound all that
> wonderful to me.
>
> The question of how to improve CNET (from an
> audiophile perspective) is an interesting one, it
> should first be noted that a PSTN portal may not be
> the most fair way to judge.  Would want to know more
> details about it (whether any additional A/D
> conversions occur, whether any compressing codecs are
> in use, how it addresses the very-tricky echo issues,
> etc).
>
> The way a CNET office sounds to well-connected callers
> from the outside world is mainly determined by the FXO
> card in use.  The X100P (and clone) FXO's are all crap
> IMHO - they're optimized for use as data modems, not
> voice; their audio dynamic range is known to be
> limited; they cut out on DC and inductive spikes, etc.
>  I don't have the hardware to test but would fully
> expect a channel bank FXO port to outsparkle an X100P,
> audio-wise.
>
>   
>> [snip] If there is no 2W segment in the call because
>>     
> it is 4W-IP end-end, echo should be non-existent. 
> Echo results from the 2W-4W junctions.
>
> This didn't make sense to me.  There's *always* at
> least one 2W segment in this case (at the ATA).
>
> In Message-ID 45944B66.7020809 at jps.net, Steph Kerman
> wrote:
>
>   
>> [snip]  I'd prefer to have the DP outpulsing of real
>>     
> wirespring sender audible to the caller, not ersatz
> "recorded" outpulsing sounds from an * box.
>
> Agreed.  However, easier said than done.  See below...
>
> In Message-ID 45954C42.6563.599D269 at localhost Chad
> Perkins wrote:
>
>   
>> I can understand that, however Asterisk nativity
>>     
> will not add nor remove outpulsing "sounds"; whatever
> goes in one end comes out the other ...
>
> I do not mean to pick on Chad, but that isn't correct.
>  Both zaptel and asterisk have code specifically to
> suppress outpulsed DP (rotary) dial digits.  A while
> back I released a patch to defeat this, in the
> interests of those demented souls (myself included)
> who wanted to hear the real dial tone and outpulsing. 
> Last time I checked there was at least one CNET office
> (try 366-3514) that still had this in effect.  The big
> letdown was that the SxS selector "clunk" sound (the
> "D" relay operating) was suppressed (by the X100P
> hardware) although the selector level hunting sounds
> were audible ...
>
>   
>> [snip] The VoIP part of CNET is a TCP/IP medium and
>>     
> I would suggest is neither 2W or 4W per se
>
> Conceptually the VOIP portion is treated as 4W, the
> two directions are processed separately...
>
> Max
>
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