[Discuss] [HH] build my own cell phone

[jack at coats.org (Jack Coats)]

I used to work for a small VOIP hardware vendor.  We sold Asterisk systems.
Getting them set up 'right' the first time is the trick.  Also VOIP
does not work
well over open internet (latency, dropped packed, traffic shaping - even when
the vendor says they don't do it, over committed networks, etc) add to
non-private
IP networks not really working well.  Yes you can get it to go, just
not as well as
you might want.

Normal VOIP systems are TCP/IP internally and when they go to the carrier
equipment (your friendly neighborhood Bell affiliate or equivalent) most folks
get T1's installed and use them for the 'analog' lines, that really stay digital
the whole way, but you don't get a data T1, you get a 'voice'.  If you
don't need
a whole T1 of voice, you can carve some data off of it, and the rest be voice.

Businesses almost must do this to have the flexibility a PBX allows with the
ability to do VOIP.

My boss then made a trip to the UK.  One day a customer called, he forgot to
un-forward his cell to his private internal line, so it got routed by
Asterisk to his
cell when he was outside London.  He conferenced me in (I was in the office
in TN) so we had a 3 way conference over VOIP internationally.  It worked.
His part of the conversation was OK, not great (as VOIP does over the open
internet).  It worked well overall.  Other than time zone issues, all was OK.

We also used OpenVPN and ssh to remotely log into customers servers for
maintenance (Mandrake and Ubuntu were our main client server bread and
butter).  Phone cards were Digium, but we sold various phones (Cisco, Snom,
Polycom, etc).  Some were better than others.  Polycom were my favorite,
Cisco was high $$, Snom was an economical alternative.  But behind it all
Asterisk as the PBX software was flexible.  We did small businesses, large
(several thousand handset) campuses, etc.

Our favorite and easiest to maintain setup was a Asterisk server in each
major building (250 or so phones), and have them trunk to each other over
a IP connection.  It allowed the most redundancy and reduced wiring
costs for most situations.

Still, each setup was individual, not cookie cutter.

Oh yes, we did use soft phones but for the most part they were of less quality
than stand alone hardware.  Dedicated networks are nice but not often
a possibility (places that did internal VPNs to keep VOIP traffic away from
data made life easier.  Otherwise dedicating lots of 'extra' bandwidth on
their own network makes VOIP work 'smoother'.

Just a few random thoughts. ... Jack