Indoor or Outdoor ONTs?

I have a lot of clients with FTTP networks and I find it interesting that they have significantly different views for placing subscriber fiber terminals (ONTs) outdoors on the side of the premise versus indoors. There are significant pros and cons for each position and many of my clients wrestle hard with the issue.

Originally in the industry the outdoor ONT was the only option and all the FTTH networks that were built until a few years ago had outdoor ONTs. But now there are pros and cons of each type of ONT, which doesn’t make this an easy decision.

Pros for Outdoor ONTs

  • An outdoor ONT allows technicians to install and service the ONT without having to schedule and coordinate with customers. In today’s world of working families this is often a huge plus in getting access to the ONTs during working hours.
  • Outdoor ONTs are generally undisturbed once installed and customers rarely touch them.
  • Creates a clear demarcation points between the ISP and the customer – what’s inside is the customer’s responsibility.

Cons for Outdoor ONTs

  • If not installed properly the ONTs can allow in water or dust and invite corrosion. But if installed properly this should not be an issue – but those who use contract installers worry about this.
  • Uses existing home wiring. In many cases that means running new copper, coaxial or Cat5 cables.
  • Can be powered outside from the electric meter, but this adds costs and in some states increases installation costs if a licensed electrician is required to tie into a meter. If powered from inside the ONT runs the risk of being unplugged by customers – a fairly common occurrence.

Pros of Indoor ONTs

  • Can be a little less expensive, but that’s not automatic and you need to consider installation labor as well as the cost of the electronics.
  • Avoids the outdoor power issue and can be plugged in anywhere in the home. This makes it easier to deploy where the customer wants it rather than where the fiber happens to hit the house. Generally easy to feed into an existing phone jack for voice service.
  • Allows for customers to help with troubleshooting by looking at the colors of various light indicators.

Cons of Indoor ONTs

  • Requires running fiber through the wall and somewhere into the home. This muddies the demarcation point between ISP and customer.
  • Since the ONT is connected to fiber, there are numerous opportunities for customer to bend, break or pinch the fiber.
  • Customers often walk away with them when they move.
  • One new issue is that many indoor ONTs now include a WiFi modem. Considering the rapid changes in wireless technologies it’s likely that the WiFi modem will need to be upgraded before the normal lifecycle of the ONT, adding considerable replacement costs over time.

The issue become further complicated by the fact that most FTTP vendors now have dual-use ONTs that can be used indoors or outdoors. But even that causes some dilemmas because these ONTs are probably not the perfect solution for either location. But these flexible-use ONTs do allow a company to put some indoors and some outdoors, depending upon the customer situation. But any company that chooses to deploy both ways then faces the dilemma of needing two different set of processes for dealing with technicians and customers – something that most of my clients try to avoid.


2 thoughts on “Indoor or Outdoor ONTs?

    • Good point. Most of clients are still buying ONTs that allow them to connect to the existing wires. Their alternative is to supply voice gateways, which, while not expensive are one more item to stock and track and another cost that can be avoided.

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