All the organizations providing or using Internet connectivity services have an associated Autonous System Number (ASN). APNIC provides statistics on the evolution of IPv6 support across the ASNs in the world, as observed in the Internet routing tables.
The percentage of IPv6-capable ASNs is growing over the years, which is a good sign. On the other hand, the table does not distinguish the degree of adoption across the different industries, that is whether the ASNs are associated to a carrier, a service provider or an entreprise. To zoom in at that level, it is necessary to look at more detailed statistics such as those provided by Akamai or APNIC.
Not unsurprisingly, the vast majority of carriers worldwide already support IPv6. Yet, differences exist. As a general rule, the carriers active in those countries with higher IPv6 adoption also show higher levels of IPv6 utilization. For example, based on the Akamai statistics, IPv6 adoption in the United States is 51%. Carriers such as AT&T, Comcast, T-Mobile and Verizon all exceed 70% of IPv6 use in their networks. In Europe, both Belgium and Germany reach 50% of IPv6 traffic. Proximus, Telenet, DT, Telefonica Germany, Versatel and Vodafone Germany range from 50% to 70%. India shows 51% IPv6 adoption. Carriers there also have a high IPv6 rate. Bharti, Reliance Jio and Vodafone India find themselves between 60% and 70%.
Whilst it cannot be gneralized, in countries with lower IPv6 adoption the local carriers also tend to be slower in enabling IPv6. For example, European countries such as Spain, Italy and Poland show respectively 4.5%, 7% and 13.5% adoption. Based on APNIC data, exluding the exceptions of Telefonica de España (26%), Vodafone Italy (21%), Wind/3 Italy (22%) and Orange Poland (23%), all the other carries sit quite below the threshold of 20% adoption.
Differences also apply between wired and wireless carriers. The latter are often more advanced with IPv6. In several cases [RFC9386], the reason for them to move to IPv6 depended on the lack of public IPv4 addresses. Those carriers have decided to develop strategic plans to enable IPv6-only underlay services, for example through the adoption of translation mechanisms such as 464XLAT (Reliance Jio, T-Mobile), guaranteeing legacy IPv4-as-a-Service support. Notable examples of early IPv6 adoption in the wired domain are Comcast in the US and Sky in the UK.