[asterisk-users] Fast detection of unreachable SIP clients?

[Dmitry Ivanov]

Hello!

I have this in my dialplan:

        Dial(SIP/${ext}, 300);
        switch(${DIALSTATUS}) {
                case BUSY:
                        Busy();
                        break;
                default:
                        Hangup();
        };

This means that SIP phone will ring for max. five minutes if 
phone can be contacted. When SIP phone is turned off or there is 
no connectivity, calling party hears many many seconds of 
silence. I want Dial() to return CHANUNAVAIL if there was no SIP 
response from the phone within 1 or 2 seconds. In this case, 
calling party will hear "out of range" message similar to mobile 
networks. Is this possible?

-- 
Dmitry Ivanov
Network engineer
Telecentrs Riga, Latvia
dimss at telecentrs.lv
(+371) 7160235

Weather at Riga Intl (EVRA/RIX): Monday 06 November 2006 10:50,29 
km/h SSE,-4°C,1004 hPa,Broken clouds at 396 meters;Overcast 
clouds at 640 meters,,  Snow;  Snow;Heavy  Snow