Initially defined in the mid-1990s, IPv6 offers a complete replacement for its predecessor, Internet Protocol version 4 (IPv4). While similar to IPv4 in many ways, IPv6 offers expanded addressing, stateless auto-configuration, enhanced Quality of Service (QoS), and mobility support.
In order for PCs, laptops, VoIP phones, tablets, smart phones, printers, televisions, gaming consoles and all other networked devices to communicate with each other, they require a unique, routable address. Most of these devices and the networks that support them currently use IPv4 addresses. As more and more people have come "online" and more and more individuals and businesses have become dependent on the Internet for much of what they do every day, IPv4 has reached a turning point.
IPv4 ExhaustionBecause it uses a 32-bit binary number, there are roughly 4.2 billion (2^32) addresses available in IPv4. That seems like a very large amount until you consider that there are more than 6.5 billion people on Earth and that to make networks work requires more than one IP per person (due to routing equipment, subnetting, etc.). It becomes quickly evident that IPv4 addresses will simply not scale with the global Internet and its multitude of attached networks and devices.
In fact, even with the use of techniques such as NAT and Classless Inter-Domain Routing (CIDR), which delayed IPv4 exhaustion and slowed address consumption, the Internet Assigned Numbers Authority (IANA) exhausted the global free pool of IPv4 addresses in February 2011.
At its core, IPv6 is the answer to this scaling problem as it uses a 128 bit binary number, offering a theoretical maximum of 2^128 or 3.4x10^38 addresses. That's 340,282,366,920,938,463,463,374,607,431,768,211,456 individual IPv6 addresses, enough for every atom on the surface of the earth!
Cable and IPv6
This abundance of addresses theoretically enables true end-to-end communications while lessening the need for address sharing technologies such as Network Address Translation (NAT).
Many cable operators are among the vanguard of IPv6 adoption in order to ensure that they can continue to provide the best possible experience to their customers, across all offered services. Much of this advantage comes from the depth of CableLabs® specifications which already support IPv6, these include: DOCSIS 3.0, DOCSIS 2.0+IPv6, eRouter, PacketCable 2.0 and OpenCable Host.
Now that the IANA has exhausted its global free pool of IPv4 addresses, the clock has begun to tick for Regional Internet Registries (RIRs) such as the American Registry of Internet Numbers (ARIN), which are expected to exhaust their supply by mid-2012. In fact, Asia Pacific Network Information Center (APNIC), the RIR for the Asia Pacific region, has already exhausted their region's free pool. Following the RIRs' IPv4 exhaustion, consumers of IPv4 addresses, such as service providers, are likely to experience depletion of their own address pools shortly thereafter.
To lessen the impact and ensure that there is ample capacity for growth and service expansion, providers should plan to leverage IPv6 and reclaim unused IPv4 address space in the near future. To that end, they must initiate IPv6 planning and deployment efforts well in advance to make sure that their infrastructure is truly ready and operational from an IPv6 point of view.
CableLabs IPv6 Project
In order to ensure the smoothest possible transition to IPv6 across the cable industry, CableLabs commissioned the now completed IPv6 project. As part of this effort, CableLabs worked with our members and technology partners to analyze and recommend requirements and best practices for both the transition to, and deployment of, IPv6. You can find more information, and the relevant references, at: