symmetric vs. asymmetric [was: Verizon Policy Statement on Net Neutrality]

Frank Bulk frnkblk at
Sat Mar 7 04:35:36 UTC 2015

The download/upload in our residential/business eyeball network has been
trending a 95th-percentile based ratio of 9:1.  If I look at a higher-ed
customer of ours who has symmetric service and has a young demographic the
average ratio is 11:1 and the peak ratio 8.8:1.  So despite access to
symmetric speeds, they're not showing a distinctively heavier symmetricity.


-----Original Message-----
From: NANOG [mailto:nanog-bounces at] On Behalf Of Mark Andrews
Sent: Tuesday, March 03, 2015 4:57 PM
To: Scott Helms
Subject: Re: symmetric vs. asymmetric [was: Verizon Policy Statement on Net


Averages hide the peak demands.  The last mile should handle the
peak demands.  Further upstream you get the over subscription
savings.  Looking at averages and saying that they define the needs
limits is *bad* engineering.  For POTS you would get a few hertz
if you did that.  The averaging of POTS comes once you combine
multiple sources together at the exchange.  Even then you look at
the peak periods not the daily average.

Asymetry is pushing oversubscription too close to the consumer.  It
is a undesirable but sometimes necessary trade off.

Asymetry traffic volumes don't mean asymetric speeds are desirable.


Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at

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