TL;DR: We don’t have a ‘Contention Ratio’. If you don’t get your full line speed, there is usually a problem with your fibre line.
🤔 What is the contention ratio on our home or business internet services? #
Contention ratios are an old commercial model. You’ll still see this in some wireless networks where spectrum is limited, but it’s mostly irrelevant in modern fibre networks. The idea comes from the days when your ISP had a 1.5Mbps internet connection and you dialled up with a 33.6Kbps modem. ISPs now have 100Gbps+ capacity in peering and transit links, when the average home line has a download speed of around 100Mbps. These days ISPs usually use transit links with a 95th percentile billing model, so there is no fixed upper limit – it scales with demand.
On Atomic’s core network, we always maintain spare capacity on all ports and uplinks. Customers can use their full line speed at any time, so there is no contention ratio on our side. If you are not achieving your full line speed, something is wrong, so open a ticket, and we’ll work with the relevant Fibre Network Operator (FNO) or upstream provider to resolve it. We also maintain more international transit than we need, from multiple upstream carriers to ensure redundancy.
⚡️ Access Network Technologies #
Different fibre networks use different last-mile technologies:
- GPON – Gigabit Passive Optical Network (Octotel, Frogfoot, Vumatel GPON and Openserve)
- AE – Active Ethernet (Vumatel)
- XGS PON -10-Gigabit Symmetric Passive Optical Network (Octotel)
GPON
GPON provides 2.488 Gbps down and 1.244 Gbps up, usually shared across 30 to 60 homes on a single PON segment. Responsible operators reduce split ratios when utilisation gets too high, but if the FNO overloads the OLT port or chains multiple splitters too aggressively, you may see slower performance during peak usage.
Active Ethernet (AE)
In an Active Ethernet network, each premises gets its own dedicated fibre strand back to the local exchange / area node. This means there is no contention on the access portion between your property and your area node.
XGS-PON
XGS-PON is the next generation of GPON, offering 10 Gbps symmetrical shared capacity across similar split ratios. The higher capacity greatly reduces the chance of peak-time contention, especially in high-usage suburbs. It is still a shared medium, but the ceiling is much higher, so performance remains consistent even with heavy user demand.
Backhaul (Local Exchange → Data Centre)
Every fibre line ultimately terminates at an area node, which aggregates traffic from multiple connections. Congestion may occur on backhaul links between the node and the core network – if the FNO hasn’t provisioned enough backhaul capacity, or if one of the backhaul links is down.
FNO SLAs
If you are not seeing your full line speed, we can work with the FNOs to troubleshoot and replace equipment until you get your full line speed.
🎛️ Factors Beyond Your Fibre Line #
IP Transit Networks
Sometimes national long-distance fibre routers or international undersea fibre routes may become congested or break, which can lead to packet loss. Moving traffic to a redundant route might introduce congestion on remaining route(s). National long-distance link repairs usually take a day or two. Undersea cable repairs can take up to two weeks.
Remote Server Limitations
Performance may also be affected by the server or service you’re connecting to. Even if your fibre line and our network are performing optimally, the destination may enforce rate limits, be geographically distant (adding latency), be under heavy load or run on slower infrastructure.