Interpreting the design

In this guide, we'll explain some common ways to interpret FOND output. We'll be using a lot of terminology specific to FOND, so we'd recommend checking out our Terminology guide for Network elements if you haven't already. 

Selecting the layers you need

Let's start by turning off the layers you don't need to see, you can do this over in the legend. Clicking on a layer name toggles it on and off. This will make it easier to click on the features that we're really interested in.

We'll start by turning off everything except the T1 Hub, T1 Cables, and Addresses.


Inspecting the Tier 1 network

Selecting the layers above allows us to inspect Tier 1 of the network. Some things to look for here:

  • Are the T1 Closures serving as close to their maximum as possible (within the maximum distance cutoff)?
  • Are there any drops that are too long due to address points being far away from the underground path or poles? Sometimes this is only apparent once you look at the design.

You can check how much demand each T1 Closure is serving by counting the Demand assigned to each Closure by each of the Tier 1 Cables. Alternatively, you can just look at the attributes of the Closure by clicking on the feature, the attribute of interest here is Demand.


Inspecting the Tier 2 network

After looking at Tier 1, inspect Tier 2. It's useful to be able to understand how everything ties together. To see how a Tier 1 Hub is connected back to the Tier 2 Hub, we can follow the relationships defined by the StartID and EndID of Cables and the FondID of Closures. The StartID corresponds to the FondID of whatever Closure/Cabinet the cable starts at. For example, the first Tier 2 Cable to come out of a Cabinet with FondID of T2_HUB_0014 will have a StartID of T2_HUB_0014. The cables EndID then shows the next element downstream, in this case, T1_HUB_0108. 


When Tier 2 cables branch, you can see the splice that they branch from by clicking on the Tier 2 Closure. For example, in the GIF below, you can see that the cable coming from the south branches at the Tier 2 Closure with FondID T2_SPLICE_0010. The southern cable has an EndID equal to T2_SPLICE_0010, and the cables leaving that splice going north and east have a StartID of T2_SPLICE_0010.

Different architectures can be interpreted in different ways. Two common ones are:

  • Spliced: T1 Hubs being spliced into Tier 2 cable, with multiple T1 hubs on each Tier 2 Cable
  • Connectorized: T1 Hubs being spliced directly back to the T2 Hub, where the Tier 2 Cables represent the tail of the Terminal/MST device.

In the spliced architecture, T1 hubs are connected back to the T2 Cabinet with connections you trace back along the Tier 2 cables via T1 Closures and T2 Closures.

In the connectorized architecture, you'll notice that the cable StartID of the Cable terminating at the T1 Closure is the T2 Cabinet - the Cable runs directly between the two without any intermediate splices.

Similar relationships can be used to trace back connectivity in Tier 3 by looking at the way Tier 2 Cabinets are connected by Tier 3 Cable.