Very noddy question about the s Extension

Hi.

I am a couple of hours into Asterisk and am familarising myself by working through the OReilly Asterisk The Future of Telephony book.

As my analogue card has not yet arrived I am using two X-Lite softphones (extns 3065 and 3062) , each running on a separate Windows boxe on the same local network as my Asterisk box. All seems fine. I can register them and make calls between them.

However on page 125 of the OReilly book it discusses the “s” Extension and on page 126 -127 the first Dialplan is produced based on this:

[incoming]
exten => s,1,Answer()
exten => s,n,Playback(hello-world)
exten => s,1,Hangup

It then suggests then I go and try it out. I try to dial from 3065 to 3062 and get a “Call Failed Not Found” message on the 3065 X-Lite screen together with an audio (“The person you are calling is unavailable please try again”). This is the same symptom as I get if I don’t put anything in the incoming section which implies that the “s” extension lines are not being executed. Note that if I replace the “s” extension lines with

exten => 3065,1,Verbose(1|Extension 3065)
exten => 3065,n,Dial(SIP/3065,30)
exten => 3065,n,Hangup()

I am able to make a call between the two devices, so everything else seems to be hanging together OK.

My sip.conf is as follows:
;----------------------------------------------------------
[general]
context=incoming
allowoverlap=no
bindport=5060
bindaddr=0.0.0.0
srvlookup=yes

[3065]
type=friend
context=incoming
host=dynamic
secret=3065

[3062]
type=friend
context=incoming
host=dynamic
secret=3062
;----------------------------------------------------------

My extensions.conf is as follows :
;----------------------------------------------------------
[globals]

[general]
autofallthrough = yes

[incoming]
exten => s,1,Answer()
exten => s,n,Playback(hello-world)
exten => s,n,Hangup()
;----------------------------------------------------------

Does anyone have any idea why the “s” extension code does not appear to be firing ?

Thanks
Marty