[160190] in North American Network Operators' Group
Re: Muni fiber: L1 or L2?
daemon@ATHENA.MIT.EDU (Owen DeLong)
Fri Feb 1 22:53:59 2013
From: Owen DeLong <owen@delong.com>
In-Reply-To: <510C3EF6.5060905@vaxination.ca>
Date: Fri, 1 Feb 2013 19:52:30 -0800
To: Jean-Francois Mezei <jfmezei_nanog@vaxination.ca>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Feb 1, 2013, at 14:17 , Jean-Francois Mezei =
<jfmezei_nanog@vaxination.ca> wrote:
> On 13-02-01 16:03, Jason Baugher wrote:
>=20
>> The reason to push splitters towards the customer end is financial, =
not
>> technical.
>=20
> It also has to do with existing fibre infrastructure. If a Telco has
> already adopted a "fibre to a node" philosophy, then it has a;ready
> installed a limited number of strands between CO and many =
neighbouhoods.
Since the discussion here is about muni fiber capabilities and ideal =
greenfield
plant designs, existing fiber is irrelevant to the discussion at hand.
> It makes sense to standardise on one technology. And if that =
technology,
> because it is used by many, ends up much cheaper due to economies of
> scale, it makes sense to adopt it.
Only if you're a single vendor looking to provide a single-vendor =
solution.
That's really not what this conversation is about, IMHO. In fact, that's =
a
pretty good summary of the situation we're trying to fix.
> And remember that it isn't just the cable. You need to consider the =
OLT
> cards. An OLT card can often support a few GPON systems each passing =
32
> homes.
Not sure why this matters...
> With 1 strand per home, you take up one port per home served. =
(possibly
> per home passed depending on deployment philosophy). So you end up
> needing far more cards in an OLT to serve the same number of people.
> More $$$ needed.
Uh, no... That's not what we're talking about. We're talking about still =
using
splitters, but, putting the splitter next to the OLT instead of near the =
ONT
end. That's all.
> GPON isn't suited for trunks. But for last mile, is it really so bad ?
Yes... Because...
> 2.mumble gpbs of capacity for 32 homes yields 62mbps of sustained
> download for each home. (assuming you have 32 homes conected and using
> it at same time)
Great by todays standards, but likely to be obsoleted within 10 years. =
Given
the nearly 100 year old nature of some copper plants, I'd like to see us =
start
building fiber plants in a way that doesn't lock us into a particular =
technology
choice constrained to the economic tradeoffs that are relevant today and
may be completely different in as little as 5 years.
> If you have multicast and everyone is watching superbowl at same time,
> you're talking up very little bandwidth on that 2.mumble GPON link.
Meh. Since everyone seems to want to be able to pause, rewind, etc.,
multicast doesn't tend to happen so much even in the IPTV world these
days.
Owen
