Caps (was Re: AT&T UVERSE Native IPv6, a HOWTO)

Mark Radabaugh mark at
Mon Dec 9 20:39:01 UTC 2013

On 12/9/13 2:03 PM, Jared Mauch wrote:
> On Dec 9, 2013, at 11:38 AM, Jay Ashworth <jra at> wrote:
>>> It costs you nothing to let people use capacity that would otherwise go
>>> to waste, and it increases the perceived value of your service. Your
>>> customers will eventually find themselves depending on that excess
>>> capacity often enough that at least some will be willing to pay you
>>> more to guarantee that it'll be there when they really want it.
>> +10
>> We've forgotten the Committed Information Rate already?
> ATM/FRAME ftw?
> I think the challenge here is that RF doesn't scale similarly to other mediums.
> Cost per bit-mile on fiber is really low compared to RF.
> If you assume 10G-LR optics (10km) @ $299 *2 (pair) + Cvt-5002sfp ($500*2)
> is around $0.16/Mbit
> RF (cheap) NB-5G25 = $95*2 (pair) is around $3.16/Mbit (assuming 60Mb/s unidirectional) or almost 20x the cost, assuming 40Mhz channel and spectrum available.
> While fiber installation can be expensive, one needs to ask the local municipalities to install extra conduit every time the earth is broken for a local project.
> - Jared

It's a lot worse on RF if you want to be able to scale to >100 customers 
per tower site.  Ubiquiti gear (NB-5G25) is dirt cheap but doesn't 
scale.  To make it work with any kind of customer density you need 
Cambium, Radwin, Redline, or a manufacturer who has GPS sync working 
properly.    70Mb = $3000 (AP + Sector antenna) + 400 (client equipment) 
for about $48.50/Mbit.

LTE is significantly higher given base station cost and spectrum licensing.

Letting customers use 'idle' bandwidth is great in theory but in 
practice it has a few problems.   We have experience with this as we 
have allowed our users to burst to maximum available speed for many years.

a) Customers become acclimated to burst speed.  Customers complain 
bitterly if the speed test that used to say 20Mb now says 6Mb even 
though they are paying for 3.5Mb.  The provider is obviously an evil 
bastard and gouging them while overloading the towers.

b) Streaming video doesn't always deal well with changing speeds. 
Netflix essentially runs a speed test at the start of the stream to 
decide on a resolution.  If it picks HD and then reaches the sustained 
limit (or in this model other users start requesting CIR bandwidth) 
Netflix does not always gracefully back down and results in a buffering 
or 'your connection has slowed' message.

c) Trying to explain 'burst' to customers is difficult at best. Leaky 
bucket policers / CIR / etc. confuse engineers.  Good luck getting 
Grandma to understand it.

We regularly get customers who are confused between 5Mbps (our plans) 
and 5GB (cell phone plans).   It's not unusual to lose a customer to a 
'faster 5GB LTE connection for $40/mo' from a uncapped 5Mbps $54.95 
service plan.   It's really not surprising when you hear back from them 
2 months later when they get a $400 bill from VerizaTT.  I really like 
the new cell company game - no overage fees for the first 60 days, and 
you have 30 days to cancel your 2 year service plan if you don't like it.


Mark Radabaugh

mark at  419.837.5015 x 1021

More information about the NANOG mailing list