China Preparing for End of IPv4 Addresses, IETF Told

The coming depletion of IPv4 addresses is the biggest technical challenge, Zhao said. The Chinese incumbent has 64 million fixed network customers and expects continued growth in the fixed and mobile network. “For a lot of new services and new applications, we additionally need billions of new addresses over the next five years,” Zhao said.

China Telecom is participating in the national IPv6 China Next Generation Internet (CNGI) project and has started a lab with Tsinghua University, said Zhao. The company is also in the middle of intensive testing of various transition technologies in several regions of the country. For the transition, “we think there are four options,” Zhao said. “One is IPv4 address optimization to raise use efficiency,” she said. Another is using what are called private IPv4 addresses, which allow operators to hide a lot of users behind Network Address Translation Devices (NAT). “We do not think this is a good solution; it is only a temporary solution,” said Zhao.

Experts like Olaf Kolkman, chair of the IETF peer group Internet Architecture Board (IAB), said the use of dynamically allocated IPv4 addresses and shared addresses would help operators for some time but will become too complex and expensive when the ratio of users behind the NAT becomes too large. Zhao also ruled out the purchase of IPv4 addresses on the “market,” something many experts have been speculating about. In the end, Zhao said, IPv6 is the only way to go. She said she expected that there would be a “cocktail” of technologies for transition.

French developer Remis Despres, author of specifications like “6rd” and “4rd” allowing the use of IPv6 addresses on islands in the IPv4 Internet or the use of IPv4 addresses over the growing IPv6 Internet, said simplicity is key and NAT technology that tends to break up some services should be kept at a minimum. Comcast Network Architect John Brzozowsk, described the experience of his company, which is testing IPv6 with 7,000 interested users. Brzozowski said there should be “no translation, not tunneling, no encapsulation”.

Bill Huang, general manager of the China Mobile Research Institute, agreed that IPv6 deployment is urgent, but said the pressing issue of IPv6 was not adequately addressed. “Our view is, based on the result of what we have seen, the fact that many people are talking about IPv6 does not really mean that we are ready,” Huang said. “Unfortunately, there has not been a very wide deployment in general, so a lot of problems are only starting to be uncovered.” Huang pointed to several technical issues not yet solved by the IETF. He mentioned transition and translation mechanisms and the compatibility of applications.

Service platforms have been developed for years based on IPv4, said Huang. Migration here was not easy, and packet filtering still is a problem with IPv6 devices. Huang asked the IETF to do more to fix problems. At the IETF, several groups are working on IPv6 and on IPv4-IPv6 transition mechanisms.

Lee Xiaodong, CTO of the China Internet Network Information Center, confirmed that real deployment of IPv6 in China is still very low. CNNIC is not only the domain name registry, but also national IP-address registry. The ratio of IPv4 to IPv6 queries is 286-1, according to CNNIC. Lee said the core problem is lack of applications and content. “We need to have more IPv6 applications. If we don’t get more IPv6 applications, there will be no IPv6,” he said. The lack of IPv6 support from a service like Skype was heavily criticized by IETF participants.

Kolkman also gave an update on ongoing privacy work that includes a highly political debate about how Internet developers should address policy issues in their work. The Center for Democracy & Technology has proposed adopting two documents that look into policy considerations in general like “how much could new standards become a tool for censoring or third party control” over users.