[Asterisk-Users] Answer Call Waiting from Call Forward to Cell Phone

[Matt Fontaine]

Hello-
	I am new to the list, so forgive me if this has been answered, but I
haven't seen it on google yet.  

What I want to know is, is there any way to send a hook-flash signal from a
cell phone (and then have Asterisk pass it up to the PSTN?)

I suspect we need an example.

I have an X100P to the PSTN and an S100U to an Analog Phone (ext. 3100)
Let's say my PSTN number is 555-1296.  Usually, I have Asterisk take
incoming calls on the X100P and send them to the analog phone on the S100U
(exten => s,1,Goto(3100)) and from time to time I set Asterisk to call my
cell phone, which it does over IAX with another asterisk server from a
different PSTN number.

What happens when another person calls me on 555-1296?  I would like to know
how to answer the call waiting both from the analog phone and from the cell
phone.  But the key is - needs to happen not at the asterisk level, but
asterisk needs to pass the flash to the PSTN.

In summary:

I call from the analog phone over IAX.  S100U in use, X100P not in use. -
Call comes in, I can flash it to take the new call.

I call from the analog phone over the PSTN.  S100U in use, X100P in use.  -
Call comes in, I hear the PSTN-generated call waiting signal, but can't
switch - Need help here.

I get a call that is sent to my cell phone.  S100U not in use, X100P in use.
- Call comes in, I hear PSTN-generated call waiting signal on my Cell Phone,
but can't switch - Need help on this one too.

Any suggestions???

Thanks!
-Matt