[e2e] Re: VoIP performance

RJ Atkinson rja at inet.org
Sun Apr 29 14:10:45 PDT 2001

At 16:41 29/04/01, Henning G. Schulzrinne wrote:
>RJ Atkinson wrote:
>> 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.
>> Fred,
>>         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.
>Can you identify this "vocoder" by name or number? 

        I'll check with the program author.  I don't know 
if it is a published algorithm or not, off hand.

>I don't think a 2.4 kb/s vocoder is acceptable voice quality, 
>however, if "recognizing the person who's speaking" is a requirement.

        I wasn't proposing a 2.4 Kbps vocoder for Fred's
purposes.  Merely noting that voice can work at 2.4 Kbps over
IP over HF (with massive jitter and channel fading);
so if one has lots more bandwidth than that, it is much easier 
to get good quality...


rja at inet.org

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