- Until May 2012, any Xs4all customer with the correct modem could opt-in to IPv6.
- At some moment, Xs4all turned on IPv6 on all its FttH's cutomers.
- At the end of May 2012 Xs4all switched to the policy that any new or upgraded customer would automatically get IPv6.
The result is that there are now 13.000 IPv6 leases (read: customers with IPv6 active). Together they generate 1.6 Gbps IPv6 peak traffic. That means a mean of 123 kbps IPv6 traffic per IPv6 user at the peak moment (normally at 21:00 for consumer connections).
This 123 kbps IPv6 mean peak traffic may sound low. However, it's quite much and it probably means that about 1/3 or 1/2 of the total traffic is IPv6, as the typical traffic peak is about 100 - 300 kbps per user.
First an explanation of that number "100 - 300 kbps per user": if you have 1000 customers each with a 10 Mbps connection, at the peak moment those 1000 customers will not generate 1000 * 10 Mbps = 10 Gbps traffic. Typically, at the peak moment those 1000 customers will generate a total of about 100 Mbps - 300 Mbps traffic, which means the mean peak traffic per customer is 100 kbps - 300 kbps. That number is used by architects to design networks.
So let's say 300 kbps mean peak traffic (IPv4 and IPv6). That means the 123 kbps IPv6 traffic accounts for 40% of the traffic. And that's much as it needs IPv6 servers / hosts on the 'other' side.
How can that huge amount of IPv6 traffic be explained? I can only guess: youtube.com, newsserer/newsgroup traffic, facebook.com, a bit google.com, and ...?
Peer2peer traffic like bittorrent is unlikely do cause a lot of IPv6 traffic at this moment as very little "peers" have IPv6 working right now.
Hopefully Xs4all will do an analysis of the type of IPv6 traffic, and report on it.