How to reach 1 Gbps on PPPoE connections: complete guide

What is the PPPoE protocol? PPPoE (Point-to-Point Protocol over Ethernet) is a standard designed to authenticate users on Ethernet networks, born in the years of the first ADSL but still used today on many fiber connections (FTTC/FTTH). Like all protocols, PPPoE also has its advantages and disadvantages that we can briefly summarize as follows: the pros are Integrated authentication (username/password) and easy management for ISPs, on the other hand, PPPoE is subject to overhead, that is, it adds about 8 bytes to packets, involves a high CPU load on routers and firewalls and has limitations at Gigabit speeds or higher. When using PPPoE it is also important to know that the MTU (Maximum Transmission Unit) parameter can influence the speed and efficiency of the Internet connection, on classic Ethernet the standard MTU is 1500 bytes, but with PPPoE it must be reduced, typically to 1492 bytes (1500 - 8). If the MTU is not set correctly, packets may be fragmented or dropped, causing retransmissions, increased latency, and even slower download/upload speeds. An MTU that is too large can cause communication problems (packets not arriving or time-outs), while an MTU that is too small wastes bandwidth by increasing the overhead. That said, if you are using PPPoE and you adjust the MTU (or your router doesn't do it automatically), you may experience a slower or more unstable connection. Setting the MTU correctly (usually 1492 or slightly less) can improve both stability and performance. Now let's explain why PPPoE limits the speed to 1 Gbps, as just explained, each PPPoE packet includes about 8 bytes of extra overhead, thus slightly reducing the effective bandwidth, however this is not the actual bottleneck, but it does contribute. Unlike IPoE, PPPoE requires the router to handle the encapsulation and de-encapsulation of the packets, which increases the CPU workload. If the router is not powerful enough, you risk not reaching Gigabit. Many consumer routers (even if they declare Gigabit ports) are not optimized to handle PPPoE at full speed because they are equipped with CPUs that are not powerful enough. Even if equipped with Gigabit ports, many devices, especially those designed years ago, cannot handle high-performance PPPoE flows. It is often thought that professional devices, even if dated, can guarantee excellent performance on modern FTTH lines. In reality, this is not the case, here are some practical examples:

It is evident that professional but "obsolete" firewall/gateway devices were designed primarily to provide advanced security (IPS, VPN, antivirus) and manage much slower Internet lines.

Even high-end devices cannot saturate a modern 1 Gbps line, especially under PPPoE sessions.

Modern Requirements for 1 Gbps PPPoE

Recommended Features

Recommended Devices

Additional Recommendations

Router/Firewall Capable of 1 Gbps PPPoE

Business Devices

Other Powerful Devices

Simpler Consumer-Grade Devices

Alternative: Industrial Mini PCs with OpenWrt

To manage 1 Gbps in PPPoE with lower costs and greater scalability, you can opt for an industrial mini PC equipped with a distribution like pfSense-CE 2.7, OPNsense 23.x, pfSense Plus, or OpenWrt.

Advantages

Technical Characteristics

Practical Examples of Mini PCs

Technical Specifications Example

Mini PC Example Configuration

With OpenWrt x86-64 installed, you can achieve over 1 Gbps in PPPoE + NAT firewall without any problems, fully manageable from a browser via LuCI.

Quick Comparison: Mini PC vs Zyxel/EdgeRouter

Mini PCs Available Online

All the above models use Intel i225-V LAN ports, well supported by OpenWrt.
Ensure you use the OpenWrt Combined EFI image for compatibility with the mini PC's UEFI BIOS.
These devices easily handle throughputs over 1Gbps for PPPoE, NAT, and firewalls, ideal for FTTH connections.