Cloudy Thinking » Blog Archive » Symmetric Gigabit Fiber Access

Symmetric Gigabit Fiber Access

There’s a dirty little “fiber to the…” secret nobody is talking about. All of the major deployments to date use passive optical network technology (PON).

There’s nothing wrong with PON, but by definition it shares the transport bandwidth of one fiber across N homes, where N varies between 8 and 16. There are several PONs: APON/BPON, EPON, and GPON. The different flavors of PON offer different speeds and use different protocols to encapsulate the data. (The trend is strongly toward Ethernet and away from ATM as the data “wrapper.”)

A VERY high performance alternative fiber access technology is starting to roll out. Active Star (refers to the network topology) Ethernet (layer 2 data encapsulation) is offered by several vendors, typically with 100 Mbps physical data rate available both from the network to the residence (downstream) as well as from the residence to the network (upstream).

Recently, vendors such as Occam Networks (where I work) have started deliver FTTx solutions that deliver a full gigabit of Ethernet bandwidth both directions.

That doesn’t mean a given service provider will SELL the full gigabit. They can (and will) tier their service offerings. My hunch is that 25 MBPS symmetric at slightly more per month than a typical DSL service would blow the doors off in terms of customer demand.

I predict: some service provider, maybe a smaller phone company, will get creative and REALLY leverage this low-cost direct DEDICATED fiber. The key is not just that the upper limit on bandwidth is a gigabit per second, but that they can chose (at an additional monthly price) to offer very fast upstream service,

This will be a game changer.

[triggered by Om Malik on DSL Speed]

This entry was posted on Saturday, January 28th, 2006 at 11:49 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

DTD

What does PON have over Ethernet?
http://blog.eronj.com Ron K. Jeffries

Fair question.

If you do not need higher bandwidth
( performance) PON can cost less if
(a BIG if…) you can uniformly use
the maximum splits.

In real networks, active star with GbE
can pencil out approx. the same as a
much slower PON system
http://blog.eronj.com Ron K. Jeffries

An industry guru writes:

I think you’re dead wrong when you write “There’s nothing wrong with PON…”

When “N = 8 to 16”, the telco has to build a new fiber all the way from the CO for every 8 to 16 subscribers. And, the telco has to build out the whole feeder route before it can hook up a single subscriber. That’s an enormous front-end load with no prospect of an ROI for years, maybe decades.

I’ve been watching Verizon pursue this folly in Plano for the last 9 months. (I’ve got lots of pictures.) They’ve spent millions and haven’t hooked up a single customer yet.

One of the strongest arguments for an active architecture is that N = several hundred, not 8 to 16. One of the strongest arguments for Ethernet is that it’s the future. Those points plus the higher throughput achievable with an active architecture make for a pretty compelling story.
http://blog.eronj.com/?p=605 Cloudy Thinking by Ron K. Jeffries » Blog Archive » Fast Uplinks Make Sense

[...] If you read my Symmetric Gigabit Fiber Access post, you already know that new “active star” fiber solutions deliver up to gigabit Ethernet bandwidth to a residence, where it splits out into several 100 Mbps Ethernets. [...]
http://gigaom.com/2006/02/03/verizon-fiber-unnecessary-roughness/ Om Malik on Broadband : » Verizon Fiber & Unnecessary Roughness

[...] Business Week article about how Verizon wants to reserve 80% of its network bandwidth for itself, caused a minor ruckus yesterday as one after another, everyone brought up the issue of network neutrality and started the finger pointing. Given the Bells past record, that was hardly a surprise. Documents filed with the Federal Communications Commission show that Verizon Communications (VZ ) is setting aside a wide lane on its fiber-optic network for delivering its own television service. According to Marvin Sirbu, an engineering professor at Carnegie Mellon University who examined the documents, more than 80% of Verizon’s current capacity is earmarked for carrying its service, while all other traffic jostles in the remainder.It did not make much sense, given how Verizon is building its network. They are using passive optical network technology (PON), where the transport bandwidth of a fiber is shared amongst N-homes, where N-varies between 8-and-16 homes. Verizon FTTH is split into two parts – one part for video transmissions and the other for data-Internet traffic. The video part of the network needs roughly 6 MHz of the spectrum to send one TV channel, and that’s why the company can currently offer only upto 120 channels. The video signals are sent to your TV set pretty much like how cable companies send their signals to consumer homes. This is TV, not IPTV, and it sucks up most of the available capacity on the network. [...]
http://blog.eronj.com/2006/02/28/brisk-demand-for-broadband/ Cloudy Thinking » Blog Archive » Brisk Demand for Broadband

[...] [see also this note on fiber access] [...]