[Asterisk-Users] PLC (Packet loss cancel) questions

[matt.riddell at sineapps.com]

On 30 Aug 2004 at 10:38, Steve Underwood wrote:

> matt.riddell at sineapps.com wrote:
> 
> >On 30 Aug 2004 at 0:26, Steve Underwood wrote:
> >
> >  
> >
> >>matt.riddell at sineapps.com wrote:
> >>
> >>    
> >>
> >>>Why doesn't asterisk clock to the 1000 interrupts per second
> >>>instead of the incoming audio?  Were there no interrupts available
> >>>when it started?  Even if you had no card you could use the ztdummy
> >>>module and even though that might be off by a bit, surely it'd
> >>>sound better than a connection which is experiencing packet loss?
> >>>
> >>>How much work would be required to change this?  I guess it
> >>>couldn't really be an option because of the totally different
> >>>structure...
> >>>
> >>>Would it be possible for one person to make those changes or would
> >>>it require the authors of all modules to recode?
> >>> 
> >>>
> >>>      
> >>>
> >>I haven't even completed by soft fax machine, and you are trying to
> >>be it completely useless. :-) Think about that. What you are
> >>suggesting is not really a satisfactory solution to anything, but
> >>certainly breaks things. :-\
> >>
> >>    
> >>
> >
> >Is this English?!
> >
> >my soft fax?
> >
> >make it completely useless?
> >
> >Okay, I think I understand you now...
> >
> >This surely wouldn't concern your code unless your code does it's
> >transmission via IAX, SIP, OpenH.323 etc?
> >
> >And unless I'm gravely mistaken fax won't work over IP anyway...
> >  
> >
> Is this a well thought out response?

Not really!  :-)

It was 5am...just before I went to sleep...

> FAX won't work over IP?

Unless you use T.38 or are connecting to a machine with no lag/packet 
loss. 

We use your software to convert from fax to tiff, email the file, 
tiff to fax at the other end...

> 
> Doesn't changing the timing in the core of * affect the PSTN channels
> as well as the IP ones?

The PSTN channels (TDM400P) are already clocked to the 1000hz 
interrupts.  The T1/E1 channels are clocked to the card remote end.

IP is clocked to incoming packets. (even though not all of those 
packets are sure to arrive etc)

> Doesn't everything - caller ID, my soft fax machine, SMS, etc. - that
> works within * all go through the * core?

Through is an interesting word, but interfaces with, yes.

> Won't this screw up everything just to keep you happy?

One would hope not!  And it's not just to keep me happy.  I just 
noticed that we seem to have a few problems at the moment that could 
be resolved by not using the incoming packets as a clocking source. 
(i.e. Silence detection, Packet Concealment, JitterBuffering etc etc)

> Won't this actually fail to keep you happy, since you don't seem to
> have thought through the whole jitter buffering issue, anyway?

LOL.

1. Keeping me happy means assuming I'm happy at the moment.
2. Yes I have thought through the jitterbuffer issue as it seems to 
be causing some problems here (we get clicks etc as it's size is 
changed by a large amount).

> So many questions. So few meaningful answers :-)

I'm sorry I'm not sure what to respond to this.

> Regards,
> Steve

Kind regards,

Matt Riddell

P.S. I LOVE YOUR WORK!  I.E. SpanDSP it seems to be working here 
really well...what's up with the site though? Been down for a while.