Replacing PBXes with Open Source

[Ken D'Ambrosio]

Kenneth E. Lussier wrote:

>On Wed, 2004-08-25 at 16:43, Ken D'Ambrosio wrote:
>  
>
>>klussier said:
>> > I agree that VoIP will be huge in emerging economies...
>>
>>Not sure... after all, you need the Internet infrastructure -- with a 
>>fair bit of bandwidth -- in place to take advantage of it.  
>>    
>>
>
>This is sort of true. VoIP can leverage existing infrastructure. If the
>end user is using a regular phone line that goes into a class V switch,
>the switch can then translate the call to IP, route the call to the
>class V switch at the other end over an IP network, which will translate
>it back and send it to the analog phone at the other end. If you want to
>go VoIP end to end, you need a lot more infrastructure. But if the area
>has old, antiquated networks and equipment, it would still be cheaper
>and faster to build a VoIP infrastructure in parallel then cut over then
>it would be to upgrade/replace their old networks and equipment.
> 
>  
>
>>I believe 
>>calls are ~80kb/s, including TCP overhead, which is a fair bit more than 
>>analog can cope with.  
>>    
>>
>
>The bandwidth needed for voice calls depend on the compression that you
>use and the signaling type. G.723 can go as low as 5.6kb/s, G.729 is
>about 8kb/s, and G.711 is about 64kb/s (which is what standard analog
>phones use). 
>
>  
>
>>On the other hand, my pesky Asterisk hardware 
>>STILL hasn't shown up a month after I ordered it, so I can't speak from 
>>experience.  (No fault of Digium; I had to go through a third-party 
>>vendor for purchasing reasons.)
>>
>>One question I have, though: how does H.323 cope with NAT, firewalls, 
>>etc., for incoming calls?  Anyone know?
>>    
>>
>
>Well, if you choose to use H.323, you will most likely need a
>gatekeeper, etc. However, I would recommend using SIP instead. 
>  
>
D'oh.  That's what I get for not being immersed, yet: I meant SIP.  Wups.

>Check out http://www.voip-info.org/wiki-Asterisk
>for all of your asterisk needs. 
>
Nifty!  Hadn't known...

>They have a lot of info for connecting
>to various providers, as well as everything you needed to know about
>Asterisk (but were afraid to ask on the users mailing list ;-)
>  
>
Yah; I'm on that list -- short of the LKM, it's the highest-volume list 
I've ever been on.  But boy, is it nifty.

-Ken