[asterisk-users] Need help designing implementation

[Chris Bagnall]

On 29/11/12 6:33 pm, Dyweni - Asterisk-Users wrote:
> I want to setup two Asterisk servers that are linked to each other:
> - The first server would be my "external" (public) server and would live
> in a real data center.  The second server would be my "internal"
> (private) server and would live in my house.
> - The external server would receive all incoming calls and handle the
> voice mail stuff.
> - The internal server would run all the phones in my house (VOIP or
> Analog-via-FXS).  All outgoing calls would be routed out through the
> external server.

That all seems perfectly doable.

> - If the external server looses connectivity to the internal server
> while a call is in progress, the external server should place the call
> on hold while it tries to reach us via our cell phones.  A message
> should be played informing the remote party that the connection had been
> lost and it is trying to re-establish it now.  If it can't reach us, it
> should inform the remote party that the connection could not be
> re-established and allow the remote party to leave some closing remarks
> on the voice mail system.

I don't think that's doable without quite a lot of work - but others may 
be able to advise further.
To elaborate a little, it's easy to detect whether a route is usable 
when a call is placed, but detecting a call failure *during* the call is 
much more difficult.

> - If a call comes in and no one is at home to take the call (or if all
> lines at home are busy), it should ring all of our cell phones and
> whoever answers the call first gets the call.  If no one answers the
> call via the cell phones after 3 rings, it should route the call to the
> voice mail system.  I say 3 rings on the cell phone because I do not
> want the cell phone voice mail to take the call.

That's easy, though remember asterisk does things in seconds rather than 
"rings".
You should also remember there's a delay in processing the call through 
the mobile networks before the phone actually starts "ringing" - in the 
UK that averages around 7 seconds between the call being sent to the 
mobile network from your server, and the phone ringing.

> - I also would like the system to automatically route all calls directly
> to voice mail depending on the time of day (say 10PM to 8AM). I would
> like specify in a "white list" specific phone numbers that are allowed
> to ring through regardless of time of day (i.e. her parents, my parents).

Shouldn't be difficult.

> - I would like the VOIP phones to turn on the voice mail waiting
> indicator light if the external server has new voice messages.

I believe this is doable in the newer versions of asterisk, but not the 
older versions. Again, someone else will hopefully chip in here, since 
our stuff is still running 1.4 :-)

> Is all of this possible?  If not, which part's are not (and how much
> work do you think would be needed to make those parts work)?

As is so often the case, (almost) anything is possible if you're 
prepared to spend time doing it. How much is worth doing depends on your 
time, and what else you might prefer to be doing with it...

FWIW, you might want to think about whether you actually need a separate 
asterisk box at home. In my experience, unless you have many dozens of 
extensions, you're almost better off (and certainly no worse off) 
connecting your SIP devices at home (assuming you're using SIP) directly 
back to the * server in the datacentre. One less box to maintain, and 
things like MWI will "just work" without having to play with the 
messaging interfaces.

Kind regards,

Chris
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