[VoIP] DP-compatible ATAs

[Chad Perkins]

On 28 Dec 2006 at 17:55, Steph Kerman wrote:

> Bearing in mind that I have 100 real PSTN DID #s and at some point
> want to allocate some of them to at least one of the SXS units, I also
> want the CNET #ing plan to overlap the PSTN #ing plan.  When calls are
> extended throught the XB to the SXS I'd prefer to have the DP
> outpulsing of real wirespring sender audible to the caller, not ersatz
> "recorded" outpulsing sounds from an * box. 

Holy crap.  What does one do with 100 DIDs?  And what do you terminate them on?

I can understand that, however Asterisk nativity will not add nor remove outpulsing 
"sounds"; whatever goes in one end comes out the other ...
:
> True but I believe that machines that inherently have
> metallic 2W trunks should be connected directly together and not go
> back and forth between 2W analog and 4W digital any more times than
> necessary.  

That's your choice.  Although I know it can be done, no one I know is doing 4W on 
Asterisk.  Myself I prefer to think E&M trunks are a better way to go (instead of FXOs 
... and Asterisk does support E&M via channel banks).

> As long as my DID trunk is delivered on analog copper, I
> won't be inserting an * between the PSTN and my switches for this
> reason.  

I can understand that and that makes sense for a small set up.

> I have no objection to inserting an * between an inherently
> 4W digital medium like CNET and my switches. 

The VoIP part of CNET is a TCP/IP medium and I would suggest is neither 2W or 4W 
per se; however CNET is 2W for most folks at the ends.
:
> In the context of
> the switching environment under discussion, that's true as long as you
> don't object to going back and forth 2W analog and 4W digital N times.

N=2 (one depending on how you do the math) just like in the PSTN.  What's the 
difference between going through an Asterisk or going through a 5ESS?  If you call 
someone next door or in the next state it goes 2W-->Digital-->2W same with CNET 
(unless the end point is a digital set/IP phone).  It is duly noted and you are on the 
record in that strict 2W local usage is the way to go for you and possibly others.  
However, as a couple have pointed out, there are some advantages to having 
Asterisk in the middle.  And for those who choose that path I don't think the digital 
transition is any great sin.

Now if you front ended 1B/1R lines with Asterisk like it was a PBX then I supposed 
you could make the argument that there is a second digital transition... well that's life.  
Commercial PBXs do the same thing in this situation.  Myself I think if I had a 100 
DIDs I'd be bringing the bulk of them in on T-carrier and keep things digital as far as 
possible and eliminate the extra digital transition (so in this scenario Asterisk would 
actually reduce the number of digital transitions).

Chad