[TriLUG] Some basic * questions

[Jon Carnes]

On Tue, 2006-05-30 at 15:48, Brian Henning wrote:
> Hi Gang (and especially Jon Carnes)!
<snip>
> So, my quick questions:
> 1 - Interface card.  What's a good tradeoff between cheap and 
> reliable/quality/ease-of-use?  Theoretically we could achieve workage 
> with a cheap sound card and some ugly wiring tricks, but of course that 
> would not be a good solution.  Also, if there're cards that can plug 
> right in to a Nortel digital PBX without needing a converter along the 
> way, it would be good to know about those, too (assuming they don't cost 
> more than the sum of the analog card and converter).
> 
Someone already pointed this out, but you don't want to go too cheap
here or your VoIP solution will end up as bad as your current PSTN
solution. If you are just looking for one or two lines, then go with the
Digium hardware. It still won't cost much and it will work very well.


> 2 - Server.  I suspect that an Asterisk installation that only has to 
> handle one call at a time shouldn't need a lot of horsepower.  What are 
> some minimum specs I should be aware of?
> 
Any decent PC that isn't way old will work fine for a small install. You
should be able to purchase a used PC or pull something out of the closet
that will get you started.


> 3 - Client-side.  What's the best PC-based client-side software to use 
> to interface with the IP side of Asterisk?  Must work in Windows and be 
> VERY easy to configure.
> 
You should start with a decent used or cheap VoIP phone like a Polycom
501. This will eliminate the problems involved in getting software
running on a Windows boxen. It also will give your remote user a nicer
initial experience to VoIP.

Once things are working *then* start cutting corners by using some of
the free VoIP software appliances. 


> 4 - Bandwidth.  The remote employee is on some flavor of cable-based 
> broadband, and we're currently on 1.5m/384k (or thereabouts) ADSL.  We 
> don't currently shove a lot of data up that pipe (most of the time), but 
> how much bandwidth does one call require?  8k is nibbling at the back of 
> my mind..

For your initial tests you will probably be better off using G711 so
you'll be using a bit more than 8kbs (which you know by now). Still this
will work fine if his bandwidth is as described above, and cable
connections generally work great. 

Cristobal Palmer's advice of using a WRT54GL is quite sound. We have
several of these deployed at various customers and they do an
outstanding job of bandwidth shaping (and Voice prioritizing). This
keeps the Voice sounding good even when the network would normally be
under load.

Good Luck - Jon Carnes
FeatureTel

> 
> Thanks a lot!
> 
> Cheers,
> ~Brian
> 
> -- 
> ----------------
> Brian A. Henning
> strutmasters.com
> 336.597.2397x238
> ----------------