[asterisk-dev] Off the wall idea - transmit wideband G722 or Speex over ISDN

[Klaus Darilion]

Stephen Davies schrieb:
> Hi,
> 
> Off the wall idea that I'd like to hear comments about:
> 
> End-to-end ISDN call is basically a 64k data pipe.
> Can we find a way to stay within the rules of ISDN, but "discover" that 
> our call is from an Asterisk box and to another.  Once we discover we 
> are talking to a friend, we could do things like switch to encoding with 
> G722 or Wideband Speex.
> 
> "Discovery" could be to send and detect a special bit-pattern (selected 
> to be inaudible or innocuous), and a similar response.  It needs to only 
> be detectable if the link is really 64k "bit clear".

You could put some information into the User-User Information Element.

One problem is that Asterisk does not support digital calls. And 
probably if Speex is not exactly 64kbit you need some bit stuffing and 
framing.

regards
klaus


> 
> How nifty would it be to pick up your SIP phone, dial a remote party and 
> suddenly find yourself on a wideband call...
> 
> Steve
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> --Bandwidth and Colocation Provided by http://www.api-digital.com--
> 
> AstriCon 2008 - September 22 - 25 Phoenix, Arizona
> Register Now: http://www.astricon.net
> 
> asterisk-dev mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-dev