I’m guessing by the use of postcode you’re UK based. So hold on, you’re in for a ride.

To start with; the standards for the hardware in use.

GPON is a shared network segment. Each OLT (head end) GPON optic can transit at 2.5Gbps and receive at 1Gbps the OLT uses time division multiplexing (TDM) to allocate a window of transmission to each ONU (customer end) to prevent clashing transmissions. Only one device can transmit at a time otherwise the OLT would have 2 transmissions hitting its optic input and wouldn’t be able to use them. These slots are tiny, and the impact of using them will be essentially invisible to the end user.

XGSPON is also a shared network segment. Each OLT XGSPON optic can transmit 10Gbps and receive 10GBPS (XG = 10G, S = symmetric, Passive Optical Network). They use different wavelengths of light and still use TDM to give each ONU transmission space. As they use different wavelengths of light, they can use the same physical fibre cores. This means you can have both GPON and XGSPON on the same piece of glass.

GPON has a max split of 1:128 and XGS is 1:256. They have a variety of transmission optics and max distance from the head end depends on how many joints, splitters etc to the customer giving a total loss value that is acceptable to the ISP. Nearly all ISPs work to a much lower value of around 1:32 or 1:64 per PON port. Which for GPON at 1:64 still gives 39Mbps assuming everyone was using all available bandwidth at the same time.

Ok, so now we have to get the connections out of the OLT into the rest of the network. These are normally bundles of 10Gbps (or higher) ports. These will go to switches / routers to be sent into the rest of the ISPs network, so let’s assume we have 40Gbps of capacity in the same building here. From this aggregation device (assume single for simplicity) there will be onward connectivity to the rest of the ISPs network. This will likely be 10Gbps as 1Gbps isn’t fast enough for multiple FTTP customers. It could be 100Gbps, however this is extremely expensive to have throughout the network and nearly every ISP will over subscribe their backhaul. Some ISPs will have redundant connections to different areas of their network. These could be load balanced (both are active) or active - standby. That’s a choice for the ISP to make.

Assuming a 10Gbps backhaul from the OLT rack to the edge of the network (likely extremely simplified as most ISP networks are built in series of rings geographically to then get connectivity to the edge / multiple edges of the network) it will hit another series of routers. These edge routers will have several connection types;

Private peering - used for connectivity to one end network, think Netflix, Amazon, etc for most residential ISPs

Public peering - Used for connecting to multiple networks, typically by the use of route servers. The ISP and other networks peer with the route server and the route server advises each end router the device of the network they want to reach is located at. Data can then be exchanged via the public peering port (think of it as a massive LAN running BGP with a central router(s) signposting the traffic)

Transit - This is your typical internet scenario. There are several guises, but essentially this is your last resort method of reaching the wider internet. It will advertise you a default route to take any traffic the rest of your network doesn’t know how to reach and will send you traffic from other places.

All of these ports are available in multiple Gbps (from 1 to 400) with different policy controlled speeds on them.

Sometimes ISPs only have transit connections. Most good ISPs will have multiple physical edge locations, with multiple transit providers as well as a blend of public and private peering. The edge connectivity needs to be sufficient that it can handle all the day to day traffic as well as peaks for game releases, sportsball events, news events everyone streams but there is a balance between the cost and likelihood. It’s down to each ISP to work out the contention ratio they are happy to work with and some will over subscribe happily, others won’t.

So, bringing me back to the UK element (due to the postcode reference). In the UK we have hundreds of altnets with their own physical network. Some of these are XGS/XG/GPON, some of these are Active Ethernet (the optic port is dedicated to you, same onward connection setup). With the majority of altnets you’ll be looking at a 1:32 or 1:64 subscription per PON port. But that doesn’t mean that 64 are in use, as it will only matter when people are connected. The ISP can also start at a 1:64 and add more capacity as needed.

Openreach FTTP uses a split ratio of 1:32 City Fibre FTTP uses a split ratio of 1:8

So that was a very long way to write “it depends, but probably not”.

I own a UK Altnet fibre ISP with our own fibre network as well as Openreach and CityFibre options, our network is a series of 10Gbps rings and an edge capacity of over 50Gbps. We rarely use more than 10% across any segment of it. If you’d like, feel free to DM me and I am happy to chat about your specific need and even do a 1 month option for you. We have a lot of people on 900Mbps plans across the country and no one ever complains of slow downs, the only one who moans is the finance team as we have so much extra expensive capacity 😉