December 22, 2009

Transition to IPv6 is Taking Time

Think back ten years. The Dow Jones Industrial Average was at 11,500; Comcast was purchasing Lenfest and Prime Cable; and IT departments around the world were feverishly preparing for the transition to the year 2000 (Y2K).

Remember Y2K? That was the “millennium bug” that resulted from the practice of shortening a four-digit year to two digits. It created a lot of panic—and revenue for companies that offered solutions to a problem that was likely overstated.

Today’s Y2K is the transition from IPv4 to IPv6, although insiders bristle at that comparison. The big difference is that this transition has no hard stop.

“When Today’s ‘Net Dies: Internet Protocol Version 4 Starts Its Long, Slow Slide To Oblivion”—that’s the headline from a Tech & Trends article from the December 18 edition of the data center publication Processor.  The operative words being “long” and “slow.”

This transition has been in the works for years. An early mover in this technology, NTT deployed a pre-commercial IPv6 network in June 2003, with native IPv6 up and running in the San Francisco Bay area, Los Angeles and Washington, D.C.

“We had Cisco 7206 routers in those three locations running dual-stack tunneling across the backbone,” said Cody Christman, director of product engineering for NTT America’s Global IP Network business unit, at an IEEE GlobeCom 2009 session webcast on Nov 30. (For a quick summary of that event, click here).

That tracks with the timing at Comcast. “We have been pushing IPv6 for about five years now,” John Jason Brzozowsksi, Comcast chief IPv6 architect and principal engineer, said in October.

Brzozowski presented a paper co-authored with CableLabs Project Director, Network Protocols, Chris Donley at the SCTE Cable-Tec Expo in Denver.

Both engineers in their respective presentations stressed the need for a carefully phased rollout.  Why so? According to Christman, that kind of approach allows for continual testing; acquisition and training of internal resources; solidification of internal processes and tools; and filling in of functionality gaps over time.

“We treated the deploying of IPv6 similar to launching a new product,” he said.

In the case of NTT Japan, there actually were new products involved, namely: “Hikari TV,” an IPTV service used by 600,000 subscribers that includes 76 channels retransmitted via IPv6 multicast. (For more on multicast, click here).

“Start with the core” and then “expand IPv6 in phases,” recommended Comcast’s Brzozowski. “Don’t try to boil the ocean.”

While a hard stop, such as that of Y2K, has the advantage of focusing the attention of everyone—technology providers and consumers alike—each network operator will exhaust its population of IPv4 addresses at different points. From a consumer perspective, that timetable may be a moving target.

For example, Internet service providers, such as Comcast, that are employing network address translation (NAT) traversal technology lengthen the period of IPv4 and IPv6 coexistence. (For more on the Comcast approach, click here).

“Trying to decide when this is going to end is probably not a good idea,” Brozozowski said. Instead, he stressed focusing on upgrading network devices and applications (both home-grown and third-party) as early as possible.

“At the 11th hour, you have very few resources,” he said.

-Jonathan Tombes