[Asterisk-Users] Sip call waiting

[John Todd]

>Hi folks,
>
>As none of the SIP softphones that I tested can disable more than one
>incoming call, I decided to implement it by software ;-) I'm attaching a
>patch that does it.
>
>To make it work, modify your sip.conf file and include callwaiting=[0|1]
>at the general section, or for each peer that you wish to control.
>
>Please note that I haven't tested it too much, and my source tree is
>quite old, so I'm not sure if this patch will apply to the current CVS.
>
>Let me know if you find something wrong asap, as this goes into
>production tomorrow !
>
>Best regards,
>
>PauloHM

Paulo -
   Have you tried using the already-existing feature of 
"outgoinglimit=" in sip.conf?  I have not tried it as a call waiting 
canceller, but you might be able to set it to "1" to get what you 
want.

http://bugs.digium.com/bug_view_page.php?bug_id=0000098

JT