The big six

The technology on which the internet is built, IPv4, is cracking under the strain of exploding demand for web utility. Now IPv6...

The technology on which the internet is built, IPv4, is cracking under the strain of exploding demand for web utility. Now IPv6 is here, but will it ease the burden? Although statistics can always be spun to suit the latest marketing opportunity and the IT business falls second only to politics in this respect, it is hard to...

ignore the facts when it comes to IPv6. The Internet is built on IPv4 technology and at 30 years old it is not surprising that it is creaking under the strain of dramatic surges in demand for access, and things will only get worse as 3G applications and services start to eat into the addressing sector. With 70 per cent of all Internet addresses utilised by the US, leaving the rest of the connected world to share a meagre 30 per cent, it is not surprising that technology leaders such as Japan are not only taking an interest in IPv6, but actively making it a reality in the here and now. Nearer to home, the Euro6IX project - next generation Internet services based on IPv6 - is being backed by the European Commission. Of course, the idea that IP address space is quickly running out is nothing new. According to differing sources, it has been rapidly depleting for years. So, with the Internet imploding, is IPv6 its saviour? "IPv6 provides a solution to the address crunch by increasing the address space from 32 bits to 128 bits. This value is estimated to accommodate ten billion devices over the Internet and although this may seem far-fetched, the reality is that computers are incarcerated into almost every facet of our lives, including household devices, PDAs and electronics," says Uri Rahamim, vice president of Hitachi Internetworking. Naturally, all of these connected gadgets will need an IP address, and then there's the small matter of mobile telephone use. Mobiles are becoming smarter by the day and Internet connectivity is a driving force. Throw 3G always-on access and the rapidly growing number of mobile users year-on-year into the mix and it doesn't take a genius to realise the problem of limited address space is very real indeed. Dire situation or red herring? Rahamim reckons "the current IPv4 scheme of four billion addresses will soon be exhausted". But it is a view not necessarily shared by all. Array Networks director of product management Steve Shah claims "when alternatives to IPv4 were initially being sought, most folks were giving every machine a real, routable IP address. At the rate that was happening, there was a genuine problem. However, three technologies changed that: HTTP/1.1 (HyperText Transfer Protocol), NAT (Network Address Translation) and CIDR (Classless Inter-Domain Routing)". HTTP/1.1 found a solution by providing virtual hosting, so single servers were able to host thousands of Web sites on a single IP. "Countless hosting providers are 'garage ISPs' that use a Linux server or two to dish up content from thousands of virtual hosts off one or two IP addresses. Why use more when you don't have to?" Shah argues. Why indeed, which is where NAT comes in to change the dynamic for many businesses, making it possible for organisations with tens of thousands of staff to comfortably fit behind a small handful of IP addresses. Of course, saving IPs was the side effect of people needing firewalls to segregate networks from the 'harsh' Internet. "Finally, CIDR made a significant impact on IP network allocation since it became possible to segment networks into subnets with as little as two IP addresses," Shah continues. Hosting providers were finally able to truly make use of a single class C network without wasting hundreds of IPs when customers wanted their own private subnet. CIDR also made a difference for those providers with class A and B networks. "Now those networks could be effectively split up and given to individual customers without relinquishing more than a few IPs," Shah concludes. Phil Goff, technical director at Allasso, agrees the address space issue has diminished somewhat in recent years because a lot of organisations are using private addressing schemes and firewalls to translate into real addresses. "Practically, this means that although they may have hundreds or thousands of IP-based systems internally, they need very few external or public addresses. The upshot is that the rate at which addresses are allocated by the Internet authorities and ISPs has reduced significantly," he argues. v4 versus v6 So if the rule of diminishing IP addresses is something of a red herring now the dynamic of Internet use is changing, where else does IPv6 have a role to play? Alexander Helmke, senior product manager at Wind River Networks Business Unit, lists some of the shortcomings he sees inherent in IPv4:

    • Its limited address space hinders further growth of devices attached to the Internet

    • It has insufficient end-to-end security, making the Internet less of a trusted medium

    • It requires complex procedures to administer and manage the network

  • It is unable to support varying qualities of service and different media types such as data, voice and video

As Rahamim says, these inadequacies are a legacy of IPv4 being an 'old' protocol conceived more than two decades ago. "IPv6 fixes problems such as class-based/classless addressing and growing routing table sizes in the Internet backbone. Its hierarchical addressing scheme and improved header will allow for more efficient IP packet processing," he insists.

Of course, IPv6 also brings many improvements in areas such as routing, simplified network auto-configuration, integrated quality of service for multimedia and voice applications, and heightened security. Yet critics such as Shah remain defiantly sceptical.

"The problem with IPv6 is that it is complicated, significantly more so than IPv4. Look back at any wildly successful technology. Ethernet is an excellent example. There were at one point countless competitors for the technology that were truly better. What made Ethernet succeed was its simplicity in implementation and deployment. IPv4 is another example of this - it is easy to configure, relatively easy to build and very widespread," he says.

Testing the water
In light of all this debate, which pretty much reflects the uncertainty and confusion regarding IPv6 at grass roots level, one might be excused for thinking it will remain a well talked about technology but never become a real world one. Excused, but wrong. Initial rollout in the UK has already started.

"The first commercial IPv6 service network, Telia/Skanova, was put in place last year using Hitachi Dual-Stack (IPv6/IPv4)

gigabit routers. These routers can handle IPv4 and IPv6 traffic at full speed," reveals Rahamim. Other carriers including British Telecom have gone through evaluations and initial trials with IPv6 products and technology - some are even providing small scale IPv6 services. It is anticipated that several carriers will have completed initial IPv6 field trials by early to mid-2003 and be ready for full deployment soon after.

Overseas, particularly in the Asian market, things are also starting to get done on the ground. Michael M. Holliday, senior product manager for IP Transit Service at Global Crossing, predicts the first mainstream commercial IPv6 services will likely be in Japan, which he sees as very aggressive in its implementation of the new protocol.

"This is due in part to mandates by the Japanese and South Korean governments regarding adoption of IPv6 by government institutions, educational facilities and large industrial concerns by 2005. Europe follows Asia, but in both cases one of the driving forces is the launch of 3G wireless. Considering that IPv6 is an important element in the operation of 3G devices, regarding the additional addresses required and the mobile routing aspects, deployment of it will need to proceed apace with the commercial rollout of 3G services," he explains.

Only fools rush in
One thing you can be crystal clear about is that transition to IPv6 will not happen overnight - far from it. The process will take several years depending on the scale of deployment. But key to successful transition is the maintenance of full backwards compatibility with IPv4.

For example, Hitachi's GR2000 has support tunnelling mechanisms that use existing IPv4 routing infrastructures to carry IPv6 traffic, and its routers implement a dual-stack approach, allowing old and new networks to run simultaneously within the same box.

Although the technological waters are far from clear where upgrading to IPv6 is concerned, only a fool would suggest sitting on one's hands in the dark and hoping the very real Internet addressing problem will simply go away. While we shouldn't rush into an IPv6 upgrade as a matter of urgency just yet, there is certainly plenty of merit in at least exploring the options and studying its business benefits and impact on budgets.

We all know the IT industry hums along to the mantra of 'if it ain't broke, don't fix it', but many of us seem content to ignore the fact that IPv4 is most definitely damaged beyond repair. Early adopters may not see a black and white ROI for their efforts, but reaping the benefits of competitive advantage and avoiding the costly last minute rush towards a solution that befell so many slack players approaching Y2K is not to be sniffed at.

A vendor's eye view of IPv6
"Carriers and service providers need to start developing an upgrade strategy to migrate to IPv6 now. Upgrading is not a trivial task and users should start to incorporate and test IPv6 into their existing network infrastructure. It is better to start sooner than later," says Hitachi Internetworking vice president Uri Rahamim.
"Without disruptions to your business, a dual-stack router which can support IPv4 and IPv6 simultaneously will allow you to continue to run your day-to-day IT operations while slowly migrating users to IPv6. This should be done in phases and the use of tunnelling techniques will make this transition transparent to users.
"The deployment strategy will more than likely dictate the costs associated with rolling out IPv6. But given the availability of dual-stack routers and tunnelling mechanisms, the rollout should be transparent from the user point of view. Users can continue to use their existing router even after the transition to IPv6.
"To avoid being unprepared when IPv6 capabilities come into demand, carriers and ISPs need to upgrade their equipment now, or face being left with useless IPv4 equipment in 18 months time. The costs and technical issues are minimal compared to the ROI.
"In the long run, IPv6 reduces network administration with its support for auto-configuration. This simplifies the tedious task of having to configure IP addresses manually during upgrades, moves and network expansion. The increase in the availability of IP addresses alone will enable new applications for consumers.
"Increase in IPv6 performance can be used to deploy multimedia business applications, thereby expanding corporate revenue streams."

Read more on IT risk management