AT&T GigaPower vs Google Fiber – (psst…They’re both GPONS and less than perfect…

Google Fiber is coming to Atlanta and everybody is excited about it.  AT&T is so excited that they are rapidly deploying GigaPower around the Atlanta area to get ahead of Google. Fiber is great, but  GPONS is not the full fiber experience.  Unlike metro-e or active ethernet, bandwidth on GPONS is shared and therefore, you can’t get full bandwidth all the time.  There is also a significant security issue with GPONS azithromycin for sale.

With corporate level Metro-ethernet, a pair of fibers (one transmit, one receive) runs from the customer all the way to the central office, where it plugs into an ethernet switch.  That pair of fibers can be easily lit to 10Gbps or more and the bandwidth is not shared, it is dedicated.  Bandwidth on a GPONS network is shared, so the ability to deliver Gbps speeds depends on what the neighbors are doing.

GPONS stands for Gigabit Passive Optical Network.  It has some very compelling strengths, like less space used in the head-end rack and lower fiber costs.  But this comes at the expense of full bandwidth and security.  On a GPONS network, the head end device (an OLT) has ports that hold a single fiber each.  By using different wavelengths, both upstream and downstream traffic uses that single fiber.  Then passive prismatic splitters are used to split that beam into multiple beams.  On some systems, the beam can be split to serve 128 homes, but it is more typical to serve 32 or 64. The OLT port is capable of 2.5Gbps downstream & 1.25 Gbps upstream.  This means that only 2 of the houses on the system can get gigabit speeds at the same time.  But ATT & Google know that people don’t all download or upload at the same time (right now).  But times may change with 4K and 3D TV & movies.

Another issue with GPONS is security.  On a GPONS network, all the downstream traffic is transmitted to all the homes on the network.  So, if you’re on a 64 house network, your web pages, email and other info is presented to the ONT at 63 of your neighbors.  This information is encrypted, but a serious geek could arrange to see it all.  Although he wouldn’t see your upstream traffic like passwords or transmitted email, the right geek with the right equipment and time could read your incoming mail, and know all the websites you went to and what you saw there.  The countermeasure to this problem is to encrypt traffic between your computer and the server.  Bank sites are always encrypted, other sites too.  Even that encryption is breakable, but not by your run of the mill geek.

GPONS is a big improvement over copper lines or even coax from the cable company.  But don’t be fooled into thinking that you’re really getting a gigabit all the time, or that it is a completely private network.

If you want more in-depth info on GPONS, click here.

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