Fibre Termination choices that define your network's scalability and ROI

There are a number of crucial choices when it comes to selecting the Broadband Fibre Optic Termination devices in your network, that can massively affect the potential scalability, future proofing and ultimately, ROI of your network build.

Of the many factors that shape your network’s performance and long-term value, a few stand out as especially critical. Let’s explore these key decisions one by one.

One-box versus two-box

Over the years, there has been much discussion about the pros and cons of a one-box or a two-box solution for Broadband and that discussion varies depending on several factors, such as which particular country you are in, or how mature the fibre industry is in that specific geography.

So, what does it mean….

One box, as its name suggests, is a single broadband device that combines the home router functions (Wi-Fi, firewall, routing, etc) with a fibre optic module for attaching the incoming fibre (this may be Point to Point or PON based, more on the difference later).

Two-box unsurprisingly involves a situation where the Broadband router does not have a fibre optic module, so a second device is required to provide this connection.

It may sound like one-box is the best solution, but that is not actually the case.

1. In markets where there are lots of smaller retail ISPs who may not have their own fibre optic infrastructure, they are buying fibre connecting service from Network Operators; therefore, they only need the router, so a one-box would not be appropriate.
2. Conversely, Network operators who only provide the Fibre termination and then don’t need customer router functionality, also do not need a one-box solution.
3. In scenarios where the ISP is also the Network Operator, so they have a vertically integrated fibre optic infrastructure, then one-box may make sense as it could reduce costs, and this is where one-box is most commonly seen; however, there is another reason not to do this.
   1. Fibre termination technology is very mature and also fairly simple so it can be installed for multiple years, potentially up to 10 years, however router technology which is generally tied to Wi-Fi, changes and improves every two to 3 years, so by using a 1-box solution consumers may be left with older router technology, whereas in a 2-box scenario the router can be replaced with newer technology, leaving the fibre termination device in place.

The summary is, it’s about finding the best cost solution that fits your particular network scenario, but generally speaking, the direction of travel for flexibility and costs is with a two-box solution.

Point to Point or PON

There are two main ways that fibre to the home solutions are provided, and as you would imagine, there are different cost models for each.

There is much discussion about the pros and cons of each method of connecting homes to broadband fibre infrastructure; some of these are technical, but some are more around scalability, flexibility and reductions in costs.

Point-to-point describes a dedicated fibre (or more realistically, dedicated fibre cores) that goes from the ISP’s access infrastructure to the customer’s house.

Its main advantage is that the connection is dedicated and therefore there are fewer security and congestion challenges to overcome.

The disadvantage is that it’s expensive to deploy as each consumer needs that dedicated connection, which means a dedicated fibre cable and more importantly, a dedicated fibre optic transceiver in the ISP’s network.

PON or Passive Optical Network uses the concept of a shared medium based on a time-synchronised slot that individual connections can transmit and receive on.

This means that any number of consumers will be sharing the same fibre optic infrastructure. The number of users sharing can vary, but is usually 16 or 32, or a multiple of this up to 128.

Now, sharing the fibre infrastructure sounds worse, so why would ISPs do this?

Because in reality, there is no discernible performance degradation caused by this to the end customer, as most Internet traffic passes in bursts so the consumer would never notice any performance issues.

The advantage of PON over Point to Point is that less infrastructure is required by the ISPs, making it considerably cheaper to deploy.

This is because the OLT (where the fibre terminates in the ISP’s network) only requires one fibre transceiver to service all the shared connections, so in an example of 32 broadband connections, there are 31 fewer fibre transceivers needed than compared to a Point to Point solution.

There is also only the need for a single fibre from the ISP’s network to the roadside cabinet or termination point adjacent to the customer’s homes.

Of course, individual fibres are required from the roadside cabinet to the consumers’ homes, but these are generally very short distances. This all adds up, meaning there is much less fibre required, thus less cost in labour and materials.

So, taking into account the savings for the passive physical infrastructure (the fibre cables) and the active equipment (fibre transceivers) and scaling up to a large network, the savings can be very large.

PON variants

There are many PON Variants, but the most common are GPON and XGS-PON, which are very mature technologies.

• GPON provides 1Gb connectivity
• XGS-PON technology provides 10Gb connectivity

In many markets, GPON is still seen as satisfactory, especially as many consumers have migrated from much slower xDSL technologies, which may be < 100 Mbps.

However, as the use of high definition video streams for gaming, VR and television is increasing, the demand for additional bandwidth is only going to increase; therefore, the rollout of XGS-PON is the common standard for many ISPs and will only accelerate.

There are, of course, many new future PON technologies available, with some ISPs considering the higher bandwidth solutions of potentially 25 or 50Gbps PON, but until there is a need for consumers to consume this much bandwidth (and critically pay for it), the advancement of these technologies is more of a future consideration and will be driven by a cost/benefit analysis of when the time is right to upgrade existing networks.

Inbuilt fibre modules or SFP/SFP+

With presenting the fibre module in the ONT, there are generally two options: do you go with a device that has a fixed fibre optic module or with an SFP/SFP+ cage that allows you to plug in different fibre optic modules.

Well, it kind of depends

The advantage of a fixed module is that:

1. It is normally cheaper than a combined SFP/SFP+ cage with a separate fibre optic module
2. The module has been confirmed to work in that particular fibre termination device and so there is no challenge with interoperability or making sure you have the right optics in place

The advantage of an SFP/SFP+ cage is:

1. It provides the flexibility that you can insert different modules. The example is you may have an ONT that can take either a GPON or XGS-PON connection.

Although it still needs to be the correct one that will work correctly with the broadband device, which is why a fixed module is more common.

In summary, the main disadvantage of an SFP/SFP+ cage and the reason why most ONTs use fixed optics is due to the increased purchase costs, so this is likely the way most network vendors and customers will continue to lean.

So why Icotera Fibre Termination?

In the PON world, many ONT vendors can also provide the OLT and having an end-to-end solution from the same vendor may sound like it makes good sense, and that is quite often how these vendors market their products.

However, the disadvantage of this is vendor lock-in, which can add to increased costs by the vendor as there is no competition, but also quite critically in a world where there is much ISP consolidation especially in key markets like the UK, ISPs may find themselves buying a network with various OLTs and ONTs and integrating them all can be painful and costly.

Icotera do not offer an OLT; rather, by using a standards-based implementation, we guarantee to work with all the major OLT vendors, such as Nokia, Adtran, Huawei, Tibit, etc.

Any development work that is required to make sure this integration works for a specific customer configuration is borne by us, not the OLT vendor.

So, this provides

• Peace of mind around interoperability and integration
• Removal of vendor lock-in
• An independent solution that can be used across various different networks
• No need for any costly integration work

Plus….

We have some innovative features that can also aid in the differentiation in a crowded market space.

In a world where enhancing Quality of Experience (QoE) for consumers is a key requirement for ISPs and Network Operators, having a solution that provides additional functionality to provide statistical information that can assist with QoE is a useful addition.

Our Baldur range of PON ONTs has the ability for the Network Operator to run industry-standard speed tests (TR-143) on the fibre termination device, a feature which previously was only available on the consumer router.

This allows Network Operators to provide evidence to the Retail ISPs of performance at the key demarcation point between the fibre termination and the consumer router.

This can help identify potential network issues and bottlenecks, which can be addressed to improve the consumers’ QoE.

This proactive approach, identifying issues before the consumer notices them, can reduce support costs and stop the churn of disgruntled customers.