Devices on the edge of the network are holding back performance of IPv6, according to networking industry officials on a panel at APNIC 38.
More than 1.5 per cent of IPv6 connections fail, compared to 0.1 per cent of IPv4 connections, according to Geoff Huston, chief scientist of the Asia Pacific Network Information Center (APNIC).
However, IPv6 itself is not to blame for the higher failure rate, Huston said. Rather, it's old filters and firewalls that have not been programmed properly for IPv6, he said.
"For certain types of equipment, the prepackaged rule is v6 does not exist [and] incoming v6 packets are evil."
Adding to the problem, most consumers who bought their broadband equipment at Dick Smith or another retailer have no plans to buy newer devices, he said.
John Brzozowski, chief architect of IPv6 for Comcast, agreed that software upgrades are a "huge issue" that "has a dramatic impact on customer experience."
Comcast has rolled out IPv6 to its cable broadband customers in the US, and Brzozowski said 30 per cent of the ISP's customers are actively using dual-stack IPv4 and IPv6.
Comcast has addressed the reliability issue by pushing firmware upgrades to customers' broadband equipment, he said.
Brzozowski said that Comcast's IPv6 rollout has not resulted in more helpdesk calls from customers.
IPv6 "has caused no more phone calls than anything else we do," he said. "As a matter of fact, I'd say it's one of the least call-generating activities that we've had."
In general, IPv6 appears to be faster than IPv4, but there are exceptions that require more research, said John Berg, a lead engineer for CableLabs, which does research for the US cable industry including Comcast.
For many sites, Wikipedia, the IPv6 speed advantage "is a millisecond or so, but it's measurable," Berg said.
However, there was little to no difference for some other sites, including Facebook and Netflix, he said. On Yahoo!, IPv4 was actually faster, he said.
However, while there were some notable exceptions, Berg said that IPv6 is still faster when looking at the results in aggregate. The median speed for IPv6 was faster, and the range of times for traffic deliver was narrower than the range for IPv6, he said.
Adam Bender travelled to Brisbane as a guest of APNIC.