[asterisk-dev] pseudo channel

[Russell Bryant]

john at spectross.com wrote:
> /* Make ring-back */
> if (tone_zone_play_tone(p->subs[SUB_CALLWAIT].zfd, ZT_TONE_RINGTONE))
>  ast_log(LOG_WARNING, "Unable to generate call-wait ring-back on channel 
> %s\n", ast->name);

If you read my previous reply, this piece of code will start to make sense.

In this case, we're dealing with call waiting.  That means that there is 
an Asterisk channel already up and connected to SUB_REAL, which is the 
DAHDI channel associated with the physical interface.  Now, we have 
another call coming in destined for this interface.  We're going to go 
ahead and set up this call with a psuedo channel.  The piece of code you 
refer to tells DAHDI to send ring back to the caller.  Meanwhile, the 
DAHDI channel associated with the physical interface is hearing a call 
waiting beep.

If this still isn't clear, I can try to draw up some ASCII art that 
demonstrates the audio flow here ...

-- 
Russell Bryant
Digium, Inc. | Senior Software Engineer, Open Source Team Lead
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: www.digium.com & www.asterisk.org