[TriLUG] DirecPC and VoIP (Kinda OT)

Jon Carnes jonc at nc.rr.com
Wed Aug 4 08:43:29 EDT 2004


On Wed, 2004-08-04 at 08:26, Michael Thompson wrote:
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> Brian McCullough wrote:
> 
> | I have recently been noticing some port blockages that I haven't in the
> | past, including those related to VOIP.
> |
> 
> Speaking of VOIP, how much bandwidth/bytes per second/whatever do a
> typical VOIP connection use?  DirecPC had an acceptable use policy that
> knocks you down to 56k if you transfer too much data within 'X' amount
> of time.  When I called them to get specifics, they flat out refused to
> tell me exactly how the system decides when to shut you down.  In my own
> tests, I could not download a file larger than about 70-90mb, and I'd
> have to wait a few hours before downloading something else, or my
> connection would drop to 56k for about a day and a half.
> 
> I wonder if your VOIP connections are over-utilizing your satellite and
> forcing the system to cut your bandwidth?

The poorest modern implementation (using G.711, the poorest codec)
averages about 40k for a conversation.

If they use a nice codec like G.729 then the average for a conversation
drops to 8k. Of course that codec is tuned to typical voice frequencies
and has problems with DTMF so it's hit/miss when trying to code in
numbers via a phone call.

Jon




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