[e2e] Re: VoIP performance

RJ Atkinson rja at inet.org
Sun Apr 29 13:27:34 PDT 2001

At 19:57 25/04/01, Fred Baker wrote:
>How about we do it the other way. You produce someone, anyone, anywhere, who says that VoIP sound quality across the North American backbone is good. We have good experience with it within highly over-provisioned LAN networks, and we have reasonable experience with it in networks that use the tools we have produced for it. But I don't hear people saying that's true over the backbone. I'm struggling to explain that fact if there is no problem anywhere.


        If you let me use vocoders of my own choosing, then
I think VoIP sound quality across any set of North American
Tier-1 providers is good.  Note well that I'm not including
smaller providers, many of whom are not overprovisioned on
bandwidth.  If you force me to use a particular standard vocoder
of your choice, I'll pass however.  It makes A LOT of difference
which vocoder is in use.

        Note that I used to work with folks who made VoIP work
over 2.4 Kbps HF radio links (~10 years ago, btw).  Given a fair 
bit more capacity, which my cable modem link of 1.5 Mbps DS &&
192 Kbps upstream provides, getting good quality voice is entirely practical today, within the limits specified above.

        That aside, I'll note that a well known Swede has deployed
VoIP among his residences in Sunnyvale CA, Tysons Corner, VA,
and Stockholm using cisco 36xx hardware.  He claims it works well.
I haven't tried it myself.  I'm pretty sure that his access links
aren't short of bandwidth, since he's quite religious about proper
bandwidth engineering.

rja at inet.org

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