[Asterisk-Users] Re: call progress - what are the sticking points?

[Steve Underwood]

Stephen David wrote:

>i don't have a specific bug in mind, i was just wondering WHY call progress doesn't work so well -- in particular, on analog lines.  ie. is it a hardware or software problem (or both).  with more info, i'd like to help to work out the kinks, for myself and everyone.  :)  
>  
>
Back in the days of Stowger exchanges you knew when the called party 
answered, by a reversal of the DC voltage on your analogue line. With 
digital exchanges that stopped, and no solid feedback is given to the 
caller on ordinary analogue lines. You have to infer that someone has 
answered, and the reliability of that can be poor. Digital lines, like 
ISDNand SS7, and protocols like MFC/R2 tell you positively that someone 
has answered.

>>I have the same problem.
>>callprogress is very experimental and buggy now.
>>and i've lost the .call files feature of asterisk.
>>what do you think about submitting a bug on bugs.digium.com?
>> 
>>    
>>
>
>not sure what you mean by 'lost the .call files feature', but if you have a specific bug to post, i think it would be great if you posted it.
>
>  
>
>> regards,
>> shabanip
>>
>> > Hello,
>> >
>> > I've been experimenting with the call progress analysis features of *,
>> > with mixed success on Zap as well as IAX channels.  I've read all the
>> > posts about it, including (but not limited to)
>> > http://www.voip-info.org/wiki-Asterisk+auto-dial+out and the pages it
>> > references.
>> >
>> > My question is, what's the current state -- is there any work in progress
>> > right now to improve the reliability of * call progress detection?  last I
>> > saw it was still listed as 'experimental'.
>> >
>> > What are the "problems" that are preventing a more robust implementation
>> > of call progress detection?   Would this work better with different
>> > hardware (ie. I've had success in the past using Dialogic telephony
>> > boards)?  Or is this primarily a software issue with *?
>>    
>>
If you had good results with Dialogic it was merely luck. Because they 
have to infer the phone has been answered, their detection only works if 
the calls follow their model of how someone answers the phone. Depending 
on your circumstances, and the nature of the calls you make, it can be 
hopelessly unreliable.

Steve