Call Without Pickup
From KlavoWiki
To call a telephone through the inbuilt speakerphone so the person does not have to pickup the phone to answer the call, use the following SIPAddHeader application before the dial command.
exten => 5555,1,SIPAddHeader(Call-Info:\;answer-after=0) exten => 5555,n,SipAddHeader(Alert-Info: Ring Answer) exten => 5555,n,Dial(SIP/201) exten => 5555,n,HangUp
I have tested this with Linksys and Polycom Phones.
NOTE: For Polycom phone to work you will need to edit the default sip.cfg file and include the additional parameters.
voIpProt.SIP.alertInfo.2.value="Ring Answer" voIpProt.SIP.alertInfo.2.class="4"
You will need to add the above entries into the section alertInfo and append them after the alertInfo.1 entries.
Don't get this function confused with Paging