[asterisk-users] Detect IP path before calling

[Eric "ManxPower" Wieling]

Yuan LIU wrote:
>> From: Paul Hales <pdhales at optusnet.com.au>
>>
>> With the chanisavail command.
>>
>> PaulH
> 
> Doesn't seem to have effect.  Probably I should state the problem more 
> clearly.  Ideally, Asterisk should not attempt SIP if there's no way to 
> establish a SIP call.  This may include lack of IP connection (ping 
> timeout, for example), or no SIP listener on remote side (this would be 
> difficult because Asterisk can only use UDP).
> 
> My environment does not require remote end point to register, so 
> consulting the registry is not an option. (This is perhaps what 
> ChanIsAvail does.)
> 
> Any suggestions?  I'll go to scripting if no other easy way.

qualify=yes in sip.conf in each [whatever] section on sip.conf should 
track if the far end is at least responding to SIP messages.

My problem is that if the far end device takes too long to respond to a 
SIP OPTIONS packet, Asterisk will consider it lagged.

I've not found any of making qualify'd devices be considered reachable 
%100 of the time when there is no actual problem.

If you are using SIP VoIP providers and failover to another route, 
qualify=yes might be something to try.

If you need reliable qualify's you might consider using the money you 
would spend on writing a monitoring script and use it to pay a bounty to 
add "qualify smoothing" to SIP similar to that feature in IAX2.