[asterisk-users] alarm POTS lines

Jeff LaCoursiere jeff at sunfone.com
Thu Dec 2 10:58:21 CST 2010


Hi,

I've brought this up in the past and there was a good discussion - am 
wondering if there have been any new developments.

Our dialtone service, like I am sure is true for most ITSPs, touts the 
ability to drop your POTs lines for significant savings.  For businesses 
we have a low-cost Atom based PBX and a "fax relay" setup locally with 
hylafax/iaxmodem to solve that issue, and it is working very well.  We 
don't however, have a solution for their alarm lines.

The problem is of course that modem calls over VoIP are flaky at best. 
Even though these alarm calls are low baud rate, when we test with the 
alarm company we only pass about 30% of the time (ulaw from customer site 
to our central switch, then out a T1).  To be fair there is no QoS on 
their Internet links yet, and that certainly plays a role.

But it seems to me that there should be a solution much like our "fax 
relay", where we literally accept the fax call over the local LAN, produce 
a PDF file, transfer it to the central switch which then dials it back out 
over a T1.  In that case the only "modem over VoIP" is on their local LAN, 
which has performed well for us.

I would love to see a DSP "modem" that could answer an asterisk channel, 
send the data stream over TCP to some remote asterisk, which could then 
"relay" the stream by making an outbound DSP modem call on a PSTN trunk. 
Has anyone attempted anything like this?

As an aside, since the recent thread on Seagate Dockstar installs, I have 
several running.  This would be the perfect platform for the "relay" on 
the customer end, being so ridiculously cheap (I bought three for $30 
each, plus 3 $10 4G USB sticks).

So hoping this will spark some comments on the concept in general, and 
really hoping someone has actually tackled something similar.  It could 
open up a nice niche for even residential customers with expensive POTS 
lines dedicated to alarm systems.

Cheers,


-- 

Jeff LaCoursiere
SunFone
jeff at sunfone.com




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