[H-GEN] voip equipment & provider

Geoff Shang geoff at hitsandpieces.net
Sat Dec 31 06:20:29 EST 2005


Tony Bilbrough wrote:

> I am going to try voip in the coming weeks, and see how it performs on a 
> Telstra Cable connection.
> Does any one have any preferences for the provider and hub?

> At the moment suggestions are Net Comm gtv 300 [$160 from UMart], with Oz 
> Tell the connector [at $4 a month].

For anyone else who doesn't have javascript: 
http://www.umart.com.au/pro/products_listnew.phtml?id=10&id2=2&bid=2&sid=14150

Specs: http://www.netcomm.com.au/SpecSheets/551778-V300%20Specs_v2-1.pdf

> But it was mooted by one, that the $86 model was more than sufficient for 
> basic voip calls, while the Telstra twin pair copper line was still 
> used/installed. Is that correct?

Do you mean the $89 VOIP adaptor on Umart, or a cheaper NetComm?

ZYXEL P2002 VOIP Analogue Telephone Adaptor $89.00: 
http://www.umart.com.au/pro/products_listnew.phtml?id=10&id2=2&&bid=2&sid=13300

This device has two FXS ports (i.e. telephone handset ports), so you can 
have two handsets on your VOIP line or two VOIP accounts.  My partner in 
Israel has one of these (bought here), and although we've had difficulty 
getting it to behave as it's meant to, I am able to call it directly from 
Asterisk with few problems (though attempting to do so from a friend's 
Asterisk still proves unsuccessful).

The P2002L is also there at $149, but it's not in stock.  This has the 
telephone line/lifeline feature like the NetComm, but no 3-port router.

If you meant the NetComm V100 (not on Umart), this has one FXS port only.

One thing that's important here is which voice codecs are supported.  All 
the above devices support G.711 and G.729.  Note however that the V100 spec 
sheet says:

* Note: G.729ab Codec can be replaced with G.723.1 upon
special request.

Whether this means this can also be done with the V300 is something you'll 
have to ask NetComm about.

Why does this matter?  Well, you can obviously only connect to people using 
the same codec.  So your VOIP provider will have to provide one of these 
codecs.

There's another reason why this matters, bit rate.  G.711 ULAW and ALAW are 
uncompressed 8000Hz PCM.  That's 64kbps.  It sounds pretty nice, but on a 
128kbps connection, you can only have one call at a time and not too much 
else going on.  And you'll chug through your quota at something like 60 
megs an hour (bigpond counts outgoing as well as incoming traffic).

And for the purists or if you intend conecting to an Asterisk server, G.729 
is non-free.  Anyone using Asterisk has to buy the codec and license at 
$10US/channel.  We bit the bullet since it's only 8kbps, dropping 
consumption to under 4 megs/hour (my ISP only counts download), so figured 
it was worth compromising my principles a little.  But if I'd realised 
this, I might not have bought this adaptor.

> Phone voip links will be to France, Spain and South Africa, mainly.

http://www.ozinternetphones.com has a directory of Australian VOIP 
providers, but don't forget that you can also use overseas providers if you 
want.  And if you only plan to make calls rather than receive them, you can 
save a lot of money (e.g. some providers have plans where you only pay for 
the calls you make).  And then there's the FWD Out Network (fwdout.net), 
where you can make calls for free if you're prepared to let other people 
use your line(they don't appear to have calling to South Africa yet 
though).

> The workstation o/s are Xandros 3 and Debian Sarge

Your computers should really not make any difference at all here, as long 
as you have a web browser for configuring the unit.

Let me know if I can be of further help.  This whole area is a bit of a 
mine field, one that I'm still learning how to navigate, but I have people 
I can ask if I get stuck.

Geoff.





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