[Asterisk-Users] call waiting from PSTN

[Seth Mattinen]

On Jun 20, 2004, at 9:40 AM, asterisk-users-request at lists.digium.com 
wrote:

> I'm trying to switch from one call to another incoming call from PSTN.
> When I'm getting a "beep" I press flash but instead of swithing to the
> second call, I'm getting a dial tone. even if I press *0, I cannot 
> connect
> to the second call.
>
> Anybody had this problem?
>

This is one of the catches I ran across while working on a new 
deployment of * in my home. The workaround I've been using is to hang 
up on the first call, at which point whatever was beeping on call 
waiting will ring the line. The drawback is that you have to hang up on 
the current call to get the call waiting call.

On the 2.x Sipura firmware there's an option for the device to send the 
hook flash event as a SIP message, but * doesn't know what to do with 
it. Support for this could be added by, for example, triggering a hook 
flash on the zap channel currently in use by the phone that sent the 
message. I haven't tried this on other phones, or looked in to this in 
any depth. I'm also pretty new to *, so I don't know how hard it would 
be for me to make a patch that would handle this.

That said, I could be totally wrong and there is a way to get the hook 
flash to translate from the phone to a zap channel, but as far as I can 
tell, there isn't.

--
Seth "cave quid dicis, quando, et cui" Mattinen
sethm at rollernet.us