How to configure an architecture

This article explains how to create a set of rules for FOND to follow when designing your network. The rules help define things like the size of cables and equipment, and the overall topology of your network.

To create a new architecture, open the architecture selection panel by clicking "Select architecture" from the Architecture drop-down on the left-hand side of any FOND project.

From this panel, you can:

- select one of your existing architectures and apply it to the project, by selecting one of the architectures in the list on the left, and clicking 'Apply to project', or

- create a new architecture by clicking the plus button Screenshot 2020-07-13 at 10.14.59. It's then a three or four-step workflow to configure the architecture, depending on the type of architecture you're creating. You then apply this new architecture to the project.

Applying architectures to projects

In a recent change in FOND, architectures are now applied to projects. After they are applied, any change made to that Project architecture will not propagate back to the original architecture, and neither will it affect other projects or users.

If you share your project with someone and give them edit rights, they can change the Project architecture in that project, but that will not affect any other architectures or projects.

Creating your architecture

General architecture settings

Step 1: Give the architecture a meaningful name so that you can find it later, as well as a description containing information that summarizes the architecture, and perhaps recommending when to use it. You can come back to these later, but naming the architecture upfront can save some trouble finding it later. 

Screenshot 2020-07-13 at 10.21.54

Step 2: Select the number of tiers in the network. To FOND, a two-tiered architecture connects homes with drop cables, and then connects the Drop closures back to a Distribution hub via a Distribution cable. This hub could be a regular splitter cabinet or distribution hub, or an active ethernet cabinet.  By selecting 3 tiers, FOND will design the Feeder network from the Distribution Hub to the Feeder Hub or Central Office.

Step 3: You can then tell FOND whether to preference aerial or underground routes. When selecting aerial, FOND will filter out any underground routes that run alongside the aerial route and so use the aerial preferentially. 

Step 4: After you have finished configuring general settings, click 'Next'.

Drop tier

In this section, we'll configure the rules for designing the Drop tier. This is everything between, and including, the drop closure and the subscriber location.

Screenshot 2020-05-13 at 17.27.13

Step 1: Select the size of the drop cable to use, the maximum number of poles within a single drop cable and its maximum length.

[Please note: Increasing the maximum drop cable length increases the complexity of the problem for algorithms (it has more options), and so will increase the design time. The maximum length is restricted to 2,000 feet. If you feel you need a longer maximum, reach out to for assistance.

Additionally: FOND will break the maximum only if it absolutely has to. For example, if an address point is 500 ft from the nearest segment of the underground path or pole, but the maximum drop cable length is 300 ft, FOND will still serve that address location by breaking that rule in that specific case.]


Step 2: Once you've created the rules for the drop cables, you can start setting rules on the type of drop closure you'll be using. Setting the Drop Hub port count limits the number of drops that can come out of a drop closure. If your closure doesn't have a port limit, set this to be the maximum number of drops that you're willing to splice into a single location. FOND will never break this rule (it's a hard constraint). You can reserve some ports as spare, as well as specify whether the closure should contain a splitter or not.

To move on to the Distribution tier select it by clicking 'Next'. 

Distribution tier

In this section, we'll configure all the rules around the distribution tier of the network, as well as connectorized drop terminals (like MSTs). 

Step 1: Check "Use connectorized drop hubs" if you want to use sort of drop terminal.  Set some limits on the tail length on the terminal, as well as the number of tails that can be spliced into a distribution cable at a single location. 

Screenshot 2020-05-13 at 17.29.53

Step 2: Review and select the cable sizes available for use. FOND will always use the minimum size cable that's available, so be sure to add some spare as a percent or the absolute number of fibers if you'd like some room for growth in the distribution cables. Note that these spares will not be connected upstream.

Step 3: Review and select your cabinet size. The section on hubs allows you to set a range of sizes that you could use for your Distribution Hub. Again, FOND will always use the smallest size available, so you can add some spare capacity here as well. This spare can be connected upstream if you wish, by checking 'Connect spare ports upstream'.

Step 4: If you're placing splitters in your cabinet, choose the splitter size that you'll be using.
This is not the overall split ratio, but the actual splitter size in the cabinet. If you're using a distributed-cascaded split, the split ratio in this step and in the Drop tier will combine to form the overall split ratio. Note that if you're trying to configure an architecture for Active Ethernet, that's achieved by setting this parameter to None. 
Step 6: The section on topology allows you to set some parameters that can be used to minimize splice locations in your network. The images below illustrate how setting these parameters can limit the number of splices. It's a good idea to play around with these a bit in some small test areas to see their effect. 
The Parallel cable threshold can be used to allow FOND to run two cables down the same path to avoid placing a splice.
Similarly, the Looping cable threshold can be used to allow FOND to loop the cable back down the same path to avoid placing a splice.

If you selected the 3 for the "Number of tiers" back at the beginning, you can now move onto the next stage by selecting "Feeder tier" from the bar at the top. Otherwise, you're done and can select "Use" in the bottom right to start designing with this architecture. 

Feeder tier

Step 1: The configuration for the Feeder tier is very similar to that for the Distribution tier, but check through the cable sizes, spare and topology parameters.
Step 2: Finish and save the creation of your new architecture by clicking the "Use" button in the lower right hand corner.

You can now use this architecture in any of your projects! Congratulations! 
You need to select "Generate design" in the project for FOND to use the updated architecture in your design.

Can I do some experimenting with configurations? 

Yes! We encourage you to experiment with architectures by tweaking parameters and observing their effects in small areas. Our own design services team maintains a set of test areas for testing, and so you might want to create a set of your own so that you can test and compare new architectures as you or your customers come up with different ideas.
If you find that you can't quite configure an architecture with the options available, please reach out to We'll either be able to give you some tips on how to model your network with the panel, or take your feedback and incorporate it into future releases.