Asterisk / VOIP for small business

[Ben Scott]

On Thu, Oct 15, 2009 at 2:44 PM, Greg Rundlett (freephile)
<greg at freephile.com> wrote:
> 1) Dealing with FairPoint communications for anything has been a
> complete nightmare - delays, misinformation, repeating requests
> without results.

  That has been my experience with every ILEC I've ever dealt with.
Large CLECs are sometimes somewhat better, but only by comparison.
I've never dealt with a small LEC.

LEC = Local Exchange Carrier
ILEC = Incumbent LEC
CLEC = Competitive LEC

  The ILEC is usually a Baby or Big Bell, but there are exceptions
(like FairPoint).  The ILEC owns the COs, and the wires on the poles.
CLECs rent the wires, and space in the CO, but generally provide their
own equipment.

> 2) Apparently call forwarding types are not all the same ...

  Welcome to the world of telecom!

> ... anything but 'remote' call forwarding depends on the number
> of 'paths' to be able to handle more than one call ...

  Longer term is "talk path" or "call path".  This has to be
programmed on the switch at the originating exchange.  (Or, at least,
it did back in the early 1990s.)  Finding a phone center person at the
repair office who understands this is nearly impossible.

> 3) Remote call forwarding solves the busy signal problem, but then you
> lose your listing in the phone book.

  You may ask about "Foreign Exchange Service" and/or "Foreign Central
Office Service".  There may be other ways (cheaper, more
sophisticated) these days, but these were how they used to do that
sort of thing, back in the old days.

  Be warned that the cost can be high.  It involves reserving voice
channels on a semi-permanent basis.  In the old days, they actually
wired up a dedicated pair all the way from the Foreign CO to your
phone.  These days, I expect they would use a PVC (Permanent Virtual
Circuit), but it's still a reservation.  And each talk path is another
reserved channel.

  I suggest this mainly because asking about this sort of thing may
get you through to someone inside the telco who actually understands
what you need, and may know a better way.  :)

> Our main private branch exchange (PBX) phone system connects to the
> PSTN / POTS through one of two trunks.

  Just as with computers, telephone terminology is really cryptic and
confusing, but critical to get right.  So:

  PSTN is the whole giant global Public Switched Telephone Network.

  POTS (Plain Old Telephone Service) is a particular type of line,
just like "PRI T1" is a particular type of line.

  POTS means a single pair of copper wires.  -48 VDC.  Analog.  Dial
tone and basic calling.  What I (and probabbly you) had in our
parents' homes when we were growing up.  The same exact technology the
phone company has offered for the past 100 years or so.

  Even "caller ID", "call waiting", etc., is technically outside of
the "POTS" definition, although most people usually say "POTS line"
even when the line has those features.

> The main corporate phone number is pointed to the T1 which is provided
> by Bayring and connected to a hardware T1 card in the PBX system

  You may want to talk to BayRing for advice.  They've been in this
business a while.

  If they can't help, find a telecom company that will.  I've heard a
couple (literally two) people recommend Paytec for the NH area, but
I've never touched them myself.

> a) checking the total bandwidth capacity at our office to ensure the
> additional call volume can be handled (already done when we initially
> just forwarded the line)

  Bandwidth measurements are almost totally unhelpful for VoIP.  A
traditional telephone voice channel, uncompressed, consumes exactly
64,000 bit per second.  With modern COCECs, that often drops under 50
Kbit/sec.  Even a crappy DSL line might give you 768 Kbit/sec --
enough for 15 simultaneous calls, in theory.

  You're interested in latency (packet delay) and jitter (packet delay
variation).  Those can be indirectly impacted by bandwidth (due to
congestion), but they're ultimately a different animal entirely.

> I'm just sharing my experience in case it is helpful ...

  Ditto.  :)

-- Ben