[Asterisk-Users] Answering incoming calls, can asterisk NOT always answer until I DO?

[Rich Adamson]

> This may be a newbie question, however,
> I am trying to get extensions working like I want.
> 
> I was wondering if it is possible to get Asterisk to detect an incoming
> call, get my extension to RING, but only ANSWER the call when I answer the
> call?
> Ie, so if no one answers the caller does not get charged.

Yes, that's the normal operation, however you can also program asterisk to
handle the incoming call in other forms as well. You will probably want to
consider using something like the following examples:

sip.conf
[3006]  ; simple example for cisco phone
type=friend
host=dynamic
username=3006
secret=mysecret
context=from-sip
mailbox=3006

zapata.conf
; This is the incoming X100P line
context=inbound-home  ; incoming x100p calls are sent to this context
switchtype=national
signalling=fxs_ks
echotraining=yes
usecallerid=yes 
hidecallerid=no
callwaiting=yes
callwaitingcallerid=no
threewaycalling=no
echocancel=yes
echocancelwhenbridged=yes
rxgain=-0.0
txgain=-0.0
callgroup=2
immediate=no
callprogress=no
musiconhold=default
channel => 1

extensions.conf
[globals]
PHONE1=SIP/3006
PHONE2=SIP/3005
[inbound-home]  ; handles inbound x100p calls
exten => s,1,Dial(${PHONE3}&${PHONE4},15)  ; rings two phones
exten => s,2,Voicemail2(u3006) ; if unanswered, call goes to voicemail
exten => s,102,Voicemail2(b3006) ; goes to busy-voicemail "if" call waiting not on phone.
exten => s,103,Hangup
[from-sip]
exten => _9X.,1,Dial,Zap/1/${EXTEN:1} ; outbound x100p calls
exten => 3005,1,Dial(SIP/3005,15,r)
exten => 3005,2,Voicemail2(u3005)
exten => 3005,102,Voicemail2(b3005)
exten => 3005,103,Hangup
exten => 3006,1,Dial(SIP/3006,15,r)
exten => 3006,2,Voicemail2(u3006)
exten => 3006,102,Voicemail2(b3006)
exten => 3006,103,Hangup

As mentioned, there are more then one way to do things. The above happens
to be just one relatively easy to follow method. It handles incoming CallerID,
voicemail, etc, just fine using C7960's.

Rich