In article <47e66f5c.2752375@news20.forteinc.com>,
Jose <go.spam@somewhere.else> wrote:[color=blue]
>On Fri, 21 Mar 2008 10:00:28 +0000 (UTC), Gordon Henderson
><gordon+usenet@drogon.net> wrote:
>
>[color=green]
>>If they're all in the office, how about a VoIP capable PBX? Connect all
>>the ATAs to the PBX, then have the PBX connect to either your existing
>>legacy PSTN connections, or SIP/IAX trunks to an ITSP (eg. the one you
>>currently use?)[/color]
>
>Hi Gordon,
>
>A Voip capable PBX seems a good idea, although I'm not sure if it
>would fit all requirements - I might have forgot to mention some:
>
>a) the ability for employees of the same company in diferent offices,
>calling each other for free, ringing exstension xxx in order to speak
>to Mr. Smith, etc
>Would a PBX allow this? Or only if the PBX had its own extension
>connected to the Voip provider? (Does such device exist, or am I day
>dreaming?)[/color]

Sure.

Disclaimer: I make & sell such a device...

Essentially, any VoIP capable PBX ought to work - where you'll have issues
is configuring your broadband connection to allow remote conections
into the PBX. It's not hard though, and very well defined. You will
need a genuine static IP address on your broadband connection and I
would strongly suggest a good business quality ISP too.

If there are a largish number of staff in each office, it might be
advantageous for each office to have it's own PBX - it's a matter of
what you need though - The PBXs can trunk calls to each other via a
slightly more efficient link that individual phones can, and the PBXs will
also allow each local office to use their exsiting PSTN infrastructure,
if required.

The limiting factor is your broadband bandwidth. For each concurrent
call, you need approx. 80Kb/sec each way, so a standard ADSL line with
400Kb/sec outgoing can handle 4 concurrent calls, a good business quality
line with 800Kb/sec outgoing speed can handle 8 or 9. With compression
it can be many more, but I do recomend getting a good quality ISP if
you plan to use VoIP. (And a good router that can handle QoS)

I generally suggest an in-house PBX for more than about 4-6 members of
staff in one location. (But my PBXs have many more facilities than my
virtual PBX offering, but there are other virtual operators who may be
more feature rich than me)

I can't stress the need for a good ISP enough. Most people here are
residential VoIP users and as such, mostly use redisential ISP offerings,
and they work well for them, but a business relying on VoIP really does
need to spend a few quid more on a good ISP. I've seen more issues with
people trying to save a few quid on a cheap ISP for their business than
just about anything else when installing VoIP.
[color=blue]
>b) the ability of employess to both receive and make PSTN calls
>(suppose the company has already PSTN numbers, which their clients
>already know, or they have a local cost number, which should allow
>clients to speak to at least some of the employees; besides, some
>information, and paid tech support support numbers, can only be
>dialled out through a PSTN line)[/color]

Indeed - You fit a PSTN card into the PBX. Analogue, ISDN2 or ISDN30
as needs require. PSTN on one side, VoIP on the other. The PBX bridges
the two. Allows VoIP to VoIP calls for all the internal extensions
(Some of which may be physically elsewhere, and not in the office),
and any extension can then make/take calls via the office PSTN line(s).
(or via a VoIP 'trunk' to an existing provider)

In some cases it may be posible to port numbers into a VoIP platform -
email me for more details.
[color=blue][color=green]
>>And you don't need ATAs... You could give people dedicated SIP
>>deskphones (or soft phones) if required - I guess it depends on the
>>existing intrastructure - if you already have a lot of analogue phones
>>cabled in, then ATAs might be the better idea... But there are 8-port
>>ATAs avalable too...[/color]
>
>I'm assuming there already loads of sophisticated analogue phones -
>it's not for me, it's for a friend.[/color]

Dedicated VoIP phones tend to be easier to use for doing things like
transfering, etc. but do watch out for any existing analogue phones -
they may be analogue, but are they part of an existing proprietary PBX
system? If you can plug one into a standard home BT socket and it works,
then you won't have a problem.
[color=blue]
>8 port ATAs - of which I found only the SPA 8000 - was big news to me.
>If not applied in this scenario, I'm sure I'll find a use for it :-)
>
>An SPA3102 with multipled ports, would be ideal.
>[color=green]
>>You can build your own PBX (eg. an asterisk based system, or trixbox),
>>but there are many pre-built systems which will do what you need it to do.[/color]
>
>I think I'll go with the prebuilt, after I've found it ;-)[/color]

Someone else has posted a link to my units - I'll leave you to find it,
or drop me an email :)

Cheers,

Gordon