There are plenty of numbers floating around about the amount of IPv6 traffic that can be seen. Whenever I go to an industry event, somebody is always presenting a number. All of them are probably accurate but they are all significantly different. What are they actually are measuring and why are they so different?
First let’s look at some numbers from different industry stakeholders:
At the Texas IPv6 Summit in September 2011, Yves Poppe from TATA communication noted that 0.061% of his traffic was IPv6. That doesn’t seem to be a lot. To simplify things, let’s round that number to 0.1%
Slides can be found here (slide 9)
At IETF81 in Quebec City in July a panel of Google, Facebook, Cisco and Yahoo! noted how much IPv6 traffic they could see on the world IPv6 day. slides can be found here.
Google could see 0.33%, facebook 0.20, Yahoo! 0.29% and Cisco could see 1.11%
This sounds better, but still not great. Let’s round this number of to 1%
Also at the TXv6TF Summit in Austin, Ron Broersma from DREN presented how much traffic he can see in his fully dual stacked network. An astonishing 10% of his traffic is over IPv6. That sounds like a lot. His slides can be found here
How come these numbers are so significantly different from each other? Well, it is because the measure different things. Remember that both a v6 capable source and an IPv6 capable destination is needed for an IPv6 session to take place. The number from the IPv6 capable content providers (1%) is measuring the amount of IPv6 capable clients. The number from DREN is actually measuring the number of IPv6 capable servers (10%). The number from the backbone provider is measuring the ratio of IPv6 traffic that is the mathematical product of the IPv6 capable clients and the IPv6 capable servers. The figure below illustrates what the different measurements actually measures.
The two conclusions that can be drawn from this exercise is that:
1. The number of IPv6 capable content far exceeds the number of IPv6 capable clients. This is alarming as it really points to the fact that service providers are not taking IPv6 seriously (there are a few exceptions).
2. Any additional clients that are being upgraded to support IPv6 will have larger impact on the total IPv6 that the Internet backbones can see than a similar increase for the IPv6 content. For example an additional 1% of clients would bring up the total Internet traffic to 0.2% (10% * 2%) whereas a 1% increase on the content side would only bring up the total backbone traffic to 0.11% (11% * 0.1%).