When creating a design in FOND, we need to first choose an architecture for the network. FOND creates networks by considering a set of constraints. These constraints are equivalent to the maximum sizes and capacities of equipment. In FOND essentials, we have a list of architectures where a set of constraints are varied.
In this guide, we’ll give an overview of the types of constraints FOND considers, and then explain how you can select your architecture before creating a design.
This guide references a lot of terms for equipment that we define in our terminology guide.
If you'd like to request a new architecture be added to the list, make a request to email@example.com.
The following terms are used to describe the ways each of our architectures may vary.
Primary splitter size
This is the splitter that usually sits within a large Cabinet (Tier 2 Hub), or sometimes in a closure if there is a smaller number of splitters. In a centralized split architecture, this is the only type of splitter available and is equivalent to the overall split ratio of the architecture. A typical value for this in a Centralised split architecture is 1:32, and in a distributed split architecture, this splitter, and the secondary splitter typically combine to produce a 1:32 split ratio.
Secondary splitter size
This is the splitter that usually sits within a Tier 1 Closure (Terminal, MST etc) close to the customers with drops running from it. Typical sizes for this splitter are 1:4 and 1:8, based on what the primary splitter is, as well as the overall split ratio
You can see in the architecture named "Distributed 1:32 split, 4-port closure, short drop", that we have a 1:8 primary splitter located in the T2 Cabinet (), and a 1:4 secondary splitter in the T1 Closure (). In the architecture named "Centralised 1:32 split, 288f Cabinet, 4-port closure", we only have 1:32 splitters, and only at the T2 Cabinet.
This is the number of fibers that may leave the Cabinet to serve the network. For example, in the architecture above named "Centralised 1:32 split, 288f Cabinet, 4-port closure", the cabinet has a size of 288f. This means there are only 288 fibers that can leave the cabinet. Therefore in a 1:32 centralized split architecture, we can have as many as 9 1:32 splitters in the cabinet
Number of ports on a closure
This is the number of ports on the Tier 1 Closure or the number of drops that can leave the closure.
The maximum distance between the customer and the terminal. FOND tries to minimize the length of every drop and will not exceed this value unless it is the only way to serve a customer.
Maximum distance from Cabinet to terminal
This is particularly relevant when users have MSTs with tails manufactured in fixed lengths, with some maximum length. In the "Centralised 1:32 split, 2 or 4 port closure, 16 prong star configuration" and "Centralised 1:32 split, 2, 4, 6, 8 or 12 port closure, star configuration" architectures which use this style of MST, these distances have been set to 1500ft.
Selecting your architecture
In FOND Essentials, the architectures list contains a list of commonly used architectures. Most of these architectures have been requested by early users of FOND.
The first thing to do after opening a new project (after renaming it!) is to choose the architecture from the list by clicking “Select architecture”.
This will open up the menu for choosing an architecture, initially choosing our default architecture. You can go ahead and use this if you’d like by clicking save, otherwise, choose a new architecture by opening the drop down.
You can scroll through the list to choose your architecture. Part of the FOND on-boarding process is to ensure that an architecture that matches your own is present in this list. If you can’t find the architecture that’s right for you, you can always get in touch with Customer support to discuss having one configured for you, or we can help you find an architecture that meets your network needs.
One of the next major features being released as part of FOND Professional will be the ability to configure and save your own architecture.
Once you’ve made your selection, click save and you’ll be taken to the next step - Input data.