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 to use for a design, or to begin editing that architecture. If you need to pause editing the architecture, select the "Use" button rather than "Cancel" (or clicking outside the panel) to save your progress.
You can also create a new architecture by selecting the plus icon in the lower left. It's then a three or four-step workflow to configure the architecture, depending on the type of architecture you're creating.
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.
Step 2: Select the number of tiers in the network. To FOND, a two-tiered architecture connects homes with drops (Tier 1 Cable), and then connects the drop closures (Tier 1 Closure) back to a hub (Tier 2 Cabinet) via a Tier 2 Cable (often called 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 Tier 3 network (often called the feeder network) from the Tier 2 Cabinet to the Tier 3 Cabinet 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 on Tier 1 from the bar at the top.
Set the rules for designing Tier 1 (or the drop tier)
In this section, we'll configure the rules for designing the Tier 1 or drop tier. This is everything between, and including, the drop closure and the subscriber location.
Step 1: Select the size of the drop cable to use (Tier 1 cable sizes), the maximum number of poles within a single drop cable (Number of poles per Tier 1 cable) and its maximum length (Tier 1 cable length).
[Please note: Increasing the maximum Tier 1 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 firstname.lastname@example.org 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 Tier 1 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 Tier 1 Closure 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 Tier 2, select it by clicking Tier 2 in the bar at the top.
Set the rules for designing Tier 2 (or the 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: By default, "Use connectorized Tier 1 closures" is set to true, so make sure to uncheck that box if you don't want to use that sort of drop terminal.
Step 2: 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.
Step 3: 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.
Step 4: Review and select your cabinet size. The section on hubs allows you to set a range of sizes that you could use for your Tier 2 cabinet (Fiber Distribution Hub, Cabinet, etc). Again, FOND will always use the smallest size available, so you can add some spare capacity here as well.
If you selected the 3 for the "Number of tiers" back at the beginning, you can now move onto the next stage by selecting Tier 3 from the bar at the top. Otherwise, you're done and can select "Use" in the bottom right to start designing with this architecture.