When I moved to Cologne 5 years ago I upgraded from a 6 Mbit/s down – 384 kbit/s up ADSL line to a 25 Mbit/s down – 5 Mbit/s VDSL line and it felt really fast. It still does, well, sort of. That's because I could recently benchmark a 1 Gbit/s Fiber to the Home (FTTH) line in France and the results are nothing short of breathtaking.
When benchmarking such a connection it's necessary to have a server on the other end that can actually deliver such high speeds, a transit/peering connection of the fiber operator that is broad enough and a device at home that can handle data at such a high speed as well. As I couldn't go and benchmark that fiber link in person, I prepared a Banana Pi to be my remote test laboratory. A Raspberry Pi would not have done as it 'only' has a 100 Mbit/s Ethernet port and the processor can handle data transfer speeds of about 30 Mbit/s. The Banana Pi on the other hand has a Gbit Ethernet port and when I tested data transfers to and from a local server before shipping it to France I could reach speeds of 80 MB/s, i.e. 640 Mbit/s. That's not the full gigabit/s the Ethernet port is capable of but to get a feeling for the fiber line it's a good start.
To access the Banana Pi remotely I prepared it to automatically establish an SSH TCP port forwarding connection to my virtual server on th net with a public IP address. Via this little detour I could connect back to the Banana Pi despite it being behind a NAT. To test up- and download speeds I used CURL and http up- and downloads. The results are breathtaking. In the downlink direction I could reach speeds average speeds of 33 MByte/s, that's around 264 Mbit/s. A "small" 160 MB Linux distribution downloads in 6 seconds and is more than 10 times the speed of my VDSL line at home… In the uplink direction I could reach speeds of around 6 MByte/s, i.e. 48 Mbit/s which is also 10 times more than what my VDSL line can do. I ran the tests at 10 in the morning, in the evening during the busiest hours and also at 4 o'clock in the morning and always got the same results.
So which part is the bottleneck, the fiber line, the peering/transit link or the server on the other end? To find that out I ran two downloads simultaneously from two different servers, one connected to the French network via Level 3 and another one that was connected via the German Internet Exchange (DECIX). With this setup I got an aggregated 33 MByte/s. This means that the fiber link into the home was the limiting factor as otherwise I would have seen a higher aggregated speed.
It's pretty amazing what a fiber line directly to the home can do today and it also shows quite clearly that the copper cable to homes won't be able to compete for much longer in areas where fiber gets deployed.