VoIP (was: Re: [LUAU] interesting article on Mark Spencer/Digium)

Tim Newsham newsham at lava.net
Fri Jun 10 18:47:10 PDT 2005


> I've been using Matt's service for a few weeks now and so far it works
> great. I'm using Residential Road Runner and I haven't needed to
> prioritize my traffic. However, if I'm downloading or uploading while on
> a call we start to breakup. Which is exactly what Matt had told me would
> happen.

Do you do any traffic shaping/rate limiting?  I've found that somewhere 
between my modem and the head end there's a bunch of buffering that starts 
filling up when I push more bits upstream that the line can handle. 
(I've noticed this on a DSL/PPPoE box with SBC as well as a normal DSL 
bridged ethernet box that verizon gives out.  I bet the PPPoE boxes
oceanic uses do this too).
Its too bad they dont just drop the bits on the floor, because
then tcp would react by limiting the amount of data it sent more
quickly.  Instead you get lot of latency on your uplink, which is sure
to muck up your voice traffic.  If I rate limit my uplink to just
under the up limit my provider gives me, I hardly see any additional
latency during a large xfer.

> As for the phones, I've tried just about every linux based soft phone I
> can find and the only one I could get working reliably was the Debian
> unstable version of kphone. Its very simple to use and it just works.
> The only problem is that I haven't figured out how get an incoming call
> to ring on my speakers and not the USB headset.

I liked the iax phone for win32 a bit.  Aren't their ports to other
platforms like linux?

Tim Newsham
http://www.lava.net/~newsham/



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