[asterisk-dev] SLA

[Kevin P. Fleming]

On 05/25/2011 05:46 PM, Damien Wedhorn wrote:
> I'm trying to get my head around some issues I'm having with
> implementing SLA into a channel.
>
> Basically, my understanding is that when a call is made into an
> SLATrunk, a call and a hint is sent to each station. For the life of me
> I can't see haw to actually identify that the hint is related to the call.
>
> The issue is that if two calls come in at the same time, the station
> will receive two hints and two calls, but how can it marry them up? The
> hint.exten will indicate the specific trunk but the call doesn't seem to.

No, this is not quite true.

When a call is sent into an SLATrunk, all SLA stations that are watching 
that trunk will receiving a state update indicating that the trunk is in 
'ringing' state; no calls will be sent to the stations.

The station needs to provide visible and audible indication to the user 
that the trunk is ringing; this same indication would be presented to 
the user even if more than one trunk was ringing.

When a user wants to answer the ringing call on the trunk, they'll press 
a line key (or go off-hook, with a phone that will send an appropriate 
call request automatically when doing so), which generates a call to the 
SLAStation application with the appropriate arguments to 'seize' that 
trunk; that endpoint is then placed into a bridge with the incoming 
channel, and the state of the trunk is changed to 'active'.. so all the 
stations will stop generate 'ringing' indications for that trunk.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
Jabber: kfleming at digium.com | SIP: kpfleming at digium.com | Skype: kpfleming
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