[Asterisk-Users] Analogical FXO vs. BRI dialing speed

[Steven Critchfield]

On Mon, 2004-02-16 at 18:30, Steve Underwood wrote:
> Steven Critchfield wrote:
> 
> >On Mon, 2004-02-16 at 07:39, Jean-Marc V. Liotier wrote:
> >  
> >
> >>When dialing out, will a call be established significantly faster by an
> >>ISDN adapter such as an Eicon Diva server compared to an analogical FXO
> >>such as Digium's X100P ?
> >>    
> >>
> >
> >Analog, nothing logical there.
> >
> >ISDN will be faster dialing out as you will communicate with asterisk
> >via the dialpad where you want to be connected too, and if you are on a
> >analog line, asterisk will repeat the digits to the telco switch in
> >analog just like you did but at a specific cadence. Since a DTMF digit
> >is around 450 to 800 msec, and in that time frame you can transfer all
> >  
> >
> Eh? A DTMF digit is about 100ms - roughly 50ms on and 50ms off. Your 
> overall conclusion is right though. Digital is much faster. On a PRI T1 
> some managers complain they only get 23 channels, while they would get 
> 24 if the used robbed bit lines. However, for lines carrying lots of 
> short calls the faster call setup on a PRI means it is usually a 
> significant win overall.

Okay. I was remembering setting my modems to 45, but couldn't remember
for sure the measurement. 45 was right before recognition started
failing.

> >the call setup information digitally, the call could be setup in the
> >equivalent of a single digits time, let alone the next 6-10 digits.
> >
> >Incoming, the calls are again signaled digitally and acknowledged with
> >the switch in less time than it takes to make the first half of a ring.
> >On analog you will want to wait till the second or third ring to get the
> >CallerID, but it was there to start with on the ISDN call.
> >
> >On my PRI line, calls are answered and prompts played without a single
> >ring event being heard by the caller.
> >  
> >
> This can be a little confusing for the caller, but thankfully it also 
> screws up a lot of telemarketer systems. Dialogic et al don't recognise 
> the phone as properly answered if they never hear the ringback tone :-)

We actually had complaints when one of our changes caused answer to be
after 2 rings. When we did more changes and made it come back to 1 ring,
they where very happy. I can't wait till our clients start the migration
to the zero ring system.
-- 
Steven Critchfield <critch at basesys.com>