Streaming dead again.

Joe Abley jabley at isc.org
Wed Feb 12 14:35:08 UTC 2003



On Wednesday, Feb 12, 2003, at 08:44 Canada/Eastern, Andrew Odlyzko 
wrote:

> VOIP is likely to cause a financial upheaval in the telecom industry,
> because the overwhelming fraction of revenues still comes from voice
> services.  However, VOIP is likely to have only a minor impact on
> Internet backbones.  The reason is that there simply isn't that much
> voice traffic.

About five years ago, before Southern Cross came live and we were 
struggling to find trans-Pacific bandwidth to New Zealand, we looked at 
the idea of running our internal voice and IP traffic between NZ and 
the US on some kind of converged network, to take advantage of the fact 
that the IP peak load and the voice peak load were about eight hours 
out of phase.

There were lots of nice graphs that showed a big trough in voice 
network utilisation almost exactly corresponding with peak IP demand, 
and everything looked very promising until you noticed that the Y axis 
on the voice graph was measured in k, and that of the IP graph was 
measured in megs. The benefit to be gained by being able to burst into 
the voice trunks was so marginal that it wasn't worth spending the time 
thinking about how we would do it.

(Every discussion involving mixing voice and data at that company 
always wound up involving ATM, too, which was another good reason to 
back away and quietly kill the idea before any madness ensued. I hear 
it didn't work, though; the company in question was happily running ATM 
over trans-pacific STM-1s after I left, with AAL5 frames intermingled 
with circuit emulation. Presumably the 30% cell tax and frame-padding 
overhead is some kind of ritual offering to the God of "QoS", that 
magic deity whose name was always invoked to explain why ATM was being 
used for anything).

If that experience is representative of today's network as a whole, 
voice is not going to add much traffic to the Internet, relative to 
traffic that is already carried.

Of course this has nothing to do with whether the Internet today is 
suitable as a transport for isochronous voice services. But it's always 
fun to recount an anecdote in which you laugh at ATM.


Joe




More information about the NANOG mailing list