IPv6: What the Transition Means for Content and Application Delivery 1IntroductionOver the next few years, the Internet will undergo a significant architectural change as its corenetwork layer protocol, Internet Protocol version 4, or IPv4, is replaced by Internet Protocol version6, or IPv6. This protocol upgrade is necessary to support the continued growth of the Internet.The transition period will take years, and the Internet will endure considerable bumps and bruisesalong the way.In particular, many of the IPv6 transition technologies that are being deployed, as well as thefragmented state of the current IPv6 Internet, will create problems for Web-enabled businessesas they try to reach their audiences across a hybrid v4/v6 Internet. While it is not difficult to supportIPv6 end users nominally, it can be far more challenging to do so with the levels of performanceand reliability users and online businesses have come to expect.This whitepaper aims to help organizations understand how the IPv6 changeover will impacttheir Web sites, and how Akamai can help them make the transition as simply and successfullyas possible. We begin with an overview of IPv6, including the growing impetus for it as well as thelack of viable alternatives. We then look at how the IPv6 transition affects content and applicationdelivery, and examine the challenges Web sites will face in trying to provide high quality experiencesto their end users. Finally, we present a phased plan for the support of IPv6 within Akamai’s serviceportfolio, which aims to enable broader IPv6 adoption by making it easy for companies to overcomethese challenges. With Akamai, IPv4 sites will be able to take advantage of high performance,high availability IPv6 delivery without making any changes to their origin infrastructures.What is IPv6?Internet Protocol (IP) is the core network layer protocol upon which the Internet is built. The currentversion of the protocol, IPv4, has been in use since the origin of the Internet. IPv6 (formerly knownas IPng or IP next generation) is the version designed to succeed IPv4.1The chief motivation for revising the existing protocol is the anticipated depletion of the IPv4 addressspace. With its 32-bit addresses, IPv4 allows for 2^32, or approximately 4 billion, unique IP addresses— a number that seemed sufficiently large when put into place in 1977, but is now clearly no longerbig enough.2 Today, there are already an estimated 2 billion Internet users worldwide3, and the num-ber of Internet-accessible devices continues to explode as users connect in growing numbers of ways— by tablet, mobile phone, set top box, and entertainment console. IP address demand growth willalso come from new applications and innovations, including always-on appliances used in utility grids,smart homes, health care monitoring, and intelligent sensor networks — the possibilities are nearlylimitless. Industry forecasts estimate there will be as many as 50 billion connected devices in lessthan ten years.4IPv6 increases address lengths to 128 bits, allowing for 340 undecillion (or 340 trillion trillion trillion)addresses — supporting an effectively unlimited number of connected devices. To visualize the differ-ence in scale, if the IPv4 address space were the size of a golf ball, the IPv6 address space would thenbe close to the size of the sun.5 If you allocated 1 trillion IPv6 addresses per second, it would takemore than 10 quintillion years to run out, or more than 700 million times the age of the universe.
IPv6: What the Transition Means for Content and Application Delivery 2The IPv6 TimelineIPv6 has been around for almost two decades. Initial IETF discussions began around 1992, and thefirst IPv6 specification (RFC 1883) was published in 1995 and updated in 1998 (RFC 2460). The firstpublic allocation of IPv6 addresses occurred the following year. Over the past decade, support forIPv6 has been added to many operating systems and applications, and it has seen deployment insome specialized environments. However, without a pressing reason or clear business case to moveto IPv6, adoption on the broader Internet has been negligible—at least until very recently, when thedepletion of the IPv4 address space became clearly imminent.IP address space distribution is managed at a global level by the Internet Assigned Numbers Authority(IANA), which allocates both IPv4 and IPv6 address blocks to the five Regional Internet Registries(RIRs). Each RIR is responsible for distributing IP blocks, based on demonstrated need, among localregistries in its own region of the globe. These local registries are generally Internet service providerswho then provide addresses and connectivity for their customers.As of December 2010, approximately 2% of the available IPv4 address space remains unallocated atIANA. Based on the depletion rate over the past decade, this means IANA will run out of addressesby mid-year 2011, if not sooner. The majority of RIRs will then have an estimated store of six monthsto a year of addresses before facing depletion themselves.7 Thus many predict that most ISPs will runout of IPv4 addresses for new customers some time in 2011 or 2012. Past this point, IPv4 addresseswill move from being a nearly free commodity to being a constrained resource that can limit growth,result in additional expenses, or require performance-impacting approaches to conserve. 40 38% 40 Remaining IPv4 Address Space (%) 36% 35 34% 32% 35 30% 30 26% 30 25 22% 25 20 17% 20 15 13% 15 10 9% 10 5 2% 5 0% 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 0 YearFigure 1: Remaining (Unallocated) IPv4 Address Space, 2000-20116
IPv6: What the Transition Means for Content and Application Delivery 3This exigency has brought a flurry of IPv6 activity over the last several years. In September 2010,the U.S. government mandated that all federal agencies make their public facing services IPv6-reachable by 20128, raising the bar on a previous mandate to support IPv6 traffic on their backbonerouters by June 2008. Access providers, who face the most immediate repercussions of address spacedepletion, are also moving forward aggressively. A recent European Commission-funded survey foundthat nearly a third of ISPs now offer IPv6 services to their business customers, and 60% intend to offerservices within a year.9 In the United States, T-Mobile, Comcast, and Verizon FiOS have all launchedIPv6 end user trials. Verizon Wireless has mandated IPv6 support for all LTE10 devices — with IPv4support optional. Meanwhile, NTT Communications in Japan began trialing IPv6 services backin 1996 and began their global launch of commercial services nearly 10 years ago.Currently, however, the percentage of IPv6 Web traffic is still very low — estimates range between0.25% and 2%.11 End user adoption is hindered both by lack of awareness and a dearth of availablecontent and services. In addition, it faces hurdles such as the lack of IPv6 support in many homewireless routers — potentially requiring the replacement of millions of these devices. But as accessproviders, particularly those in fast growing markets such as Asia and the mobile space, run outof IPv4 addresses and begin provisioning IPv6 customers wholesale, adoption patterns could changerapidly. T-Mobile USA, for example, expects that 50% of their traffic will be native IPv6 by the endof 2011.12 And on the desktop, over 90% of the installed base of operating systems is IPv6-capable,while the latest operating systems — Microsoft Vista, Microsoft Windows 7, Apple Mac OS X, andall major Linux distributions — have IPv6 enabled by default.13 This means conditions are ripe forIPv6 adoption to soon reach its tipping point.Are there viable alternatives to IPv6?A number of strategies have been adopted by network operators in an effort to delay addressdepletion and thereby prolong the life of IPv4. Approaches include trying to recover allocatedbut unused addresses or trying to purchase IP blocks on a limited secondary market. Both ofthese approaches have associated costs and risks, and ultimately provide only very short termrelief as depletion continues at a rate of roughly 16 to 20 million IP addresses per month.14 Withglobal Internet adoption continuing at a rapid pace the roughly four billion addresses availablein IPv4 simply are not sufficient.Perhaps the most popular approach to conserving IPv4 addresses relies on the use of NAT,or Network Address Translation. NAT comes in several flavors and involves mapping one setof IP addresses to another; it is commonly used to enable multiple devices within a single homeor small office network to be mapped to a single public IP address provided by an ISP. More recently,broadband and wireless access providers have begun deploying the same technology within theirown networks, where it is referred to as Carrier Grade NAT (CGN) or Large Scale NAT (LSN). Here,it can be used to map dozens of different users (thousands of user sessions) to a single public IPv4address by using 16-bit port numbers to distinguish between them.15Unfortunately, this many-to-one IP mapping creates numerous complications. Applications that relyon differentiating end-users by IP address may simply stop working effectively, including VPNs, VoIP,peer-to-peer, geo-location, and IP blacklisting/graylisting/whitelisting (used to prevent spam, fraud,and other abuses). These problems are exacerbated when communications span several NATs —such as the end user’s home NAT, the end user’s ISP CGN, and then the destination network’s CGN.
IPv6: What the Transition Means for Content and Application Delivery 4CGNs also come with high capital and operational costs. In addition to their computationaloverhead, CGNs can create significant logging requirements, and they make auditing and trouble-shooting difficult. CGN gateways can also become single points of failure, attractive Denial-of-Servicetargets, or performance bottlenecks within the network. Because of these many drawbacks, CGNsare not a sustainable solution. They are only considered a stopgap measure — a necessary evil delayingaddress depletion long enough for the Internet to broadly support IPv6.Ultimately, although the timing of the transition is still unclear, we have reached the point whereIPv6 adoption will become a tangible issue for Web content providers.IPv6 adoption statusOver the next few years, the IPv6 transition will affect every business that touches the Internet in anyway. For wireless carriers and Internet access providers, planning began years ago and the conversionis already well underway, with current metrics reflecting reasonable progress on infrastructure readi-ness (i.e., networks, DNS, operating systems).On the other hand, end user and content provider adoption is still in relative infancy. Here, thereis a chicken-and-egg dynamic: many content providers don’t want to make significant investmentsuntil there are more IPv6 end users, while audiences are reluctant to shift until they can enjoy anend user experience that is on par with IPv4, in both quality and quantity.Still, companies should not be lulled into complacency by the current metrics. Content providers needto be ready, as adoption could quickly snowball with any small shift in marketplace forces. Indeed,now is an ideal time to start planning, testing, and experimenting, while the percentage of end users— and thus, the risks — are still minimal. Once the IPv6 audience grows, content providers who cannotprovide IPv6 delivery will find themselves at a clear competitive disadvantage. Infrastructure Readiness Metrics • As of December 2010, only about 7.9% of networks (ASes) advertise IPv6 support. However, this is up significantly from 5.5% reported in early 2010.16 • As of March 2010, 22% of transit networks support IPv6, double of March 2009. This number is projected to reach 80% by 2013.17 • Roughly 25% of the current installed base of operating systems has IPv6 enabled by default, while 90% is IPv6-capable.18 Adoption Metrics • In roughly 8 months (ending December 14, 2010), the number of Web sites in the global top 500 supporting IPv6 grew 83%, from 2.4% to 4.4%.19 • Several sources note that IPv6 only accounts for about 1% of end user traffic.
IPv6: What the Transition Means for Content and Application Delivery 5How does IPv6 affect Web content and application delivery?In an ideal world, the IPv6 changeover would be seamless to end users and relatively seamless tocontent providers, who would simply need to procure IPv6 connectivity from their ISPs and upgradetheir server infrastructure to handle the new protocol. Unfortunately, the reality is far more complex.IPv6 is not backward compatiblePerhaps the biggest challenge in the IPv4-to-IPv6 transition is that the two protocols are not compatible;that is, IPv4-only systems cannot talk directly to IPv6-only systems. This means no one can turn off IPv4support until every last device they want to reach has acquired IPv6 connectivity. Unfortunately, manyexisting devices — including PCs running older OSes, as well as older cable and DSL modems, wirelessrouters, and other business and consumer electronic devices—have either limited or no IPv6 support.In other words, companies will have to support both protocols for years to come, in a long and bumpytransition period. During that time, there will effectively be two Internets, an IPv4 one and an IPv6 one,loosely bound together into a hybrid Internet by various transition technologies.The key transition technologies include:• Dual Stacking: Dual stacking simply refers to machines running both the IPv4 and IPv6 protocol stacks. Hosts within a dual stacked network can communicate over IPv4 or IPv6. Dual stacking will be common during the transition and may be deployed by enterprises, content providers, and networks. However, it requires hardware and software support that may not be available on legacy equipment. It also requires that having enough IPv4 address space for all dual stacked devices, so it will be of more limited use for fast-growing networks.• CGN/NAT64: NAT6420 is a type of Carrier Grade NAT that can be used to provide connectivity between IPv6 hosts and IPv4 hosts by translating between IPv6 and IPv4 packet streams. Like other types of CGN, NAT64 can produce significant functional and operational challenges. It also creates a single point of congestion (or failure) that can affect all the users within the network.• Tunneling (e.g., 6to4, 6RD, Teredo, etc.): Tunneling typically involves encapsulating IPv6 packets inside of IPv4 packets, in order to allow two IPv6 nodes to communicate over IPv4 infrastructure. Tunneling came about because IPv6 connectivity was very fragmented — and insufficient. Unfortu- nately, these tunnels are often unmanaged and sometimes provisioned dynamically, and can cause significant performance, reliability, and security issues. Preliminary data collected by Akamai shows that, as of December 2010, a majority of clients with existing IPv6 connectivity reach the IPv6 Internet through 6to4 tunnels.Each transition technology has its limitations and drawbacks — but they are necessary to hold theInternet together until the long IPv6 migration is complete. We now take a closer look at the impactthe IPv6 transition will have on delivering content and applications over the Web.
IPv6: What the Transition Means for Content and Application Delivery 6Challenges of delivering content in a hybrid InternetDuring the IPv6 transition, content providers will face a number of challenges when tryingto deliver fast and reliable Web interactions to their IPv6 audiences. These stem from limitationsin the transitional technologies, uneven vendor support of IPv6, and the extremely fragmentedstate of the current IPv6 Internet.Challenges of reaching IPv6 users from IPv4 sitesThe first question for a content provider to consider is whether (or when) to provide native IPv6connectivity for their site. In the near term, an IPv4 site will generally be able to reach end usersconnected via IPv6. These communications will likely be through Carrier Grade NAT64 gateways,run by the end user’s ISP, that translate between the IPv6 last mile network and the IPv4 Internet.Unfortunately, CGN creates a host of problems for content providers, including loss of performance,visibility, and functionality.21 Key challenges include:• Broken location-aware services, abuse mitigation, and other IP address-reliant functions. Many types of Web applications rely on an end-to-end connection, where each device, household, or entity is associated with a single IP address. CGN breaks this assumption — as it creates a situa- tion where hundreds or thousands of end users — related only by their network provider — share the same IP address, and each user’s IP address may change with every new connection. Thus, CGN cripples functions like geo-location — using the user’s IP address to determine their location, in order to personalize content or to enforce licensing restrictions, for example, and abuse mitiga- tion — IP blacklisting or whitelisting, in order to block spammers, trolls, or other abusive users. Likewise, Web site analytics relying on geo-location data to provide audience demographics also become impaired.• Broken applications. CGN (especially as it is typically applied in multiple layers) breaks assumptions that many of today’s Web applications rely on. In particular it affects applications, such as peer-to- peer and VoIP, which rely in some way on a unique end user IP address. Troubleshooting the issues is extremely complex and costly, as it can’t be done without the NAT operator’s help.• Poor performance. In order to reach IPv4 sites, IPv6 end users need to go through a NAT64 gateway. Because there may be only one or two such gateways within a network, communications may be forced through long, indirect paths. In addition, these gateways quickly become congestion points within the network, as well as easily targeted points of failure, further affecting the perfor- mance and reliability of the end user experience.These significant performance and functionality problems underscore the need for sites to providenative IPv6 delivery capabilities as their IPv6 user base grows. While IPv6 users currently representless than 2% of the total user base, this number is expected to grow rapidly once access networksrun out of IPv4 addresses. Thus, forward-looking sites will want to begin experimenting with IPv6delivery capabilities in 2011.
IPv6: What the Transition Means for Content and Application Delivery 7Challenges of reaching IPv6 users from IPv6 sitesTechnically, a content provider could start delivering content to IPv6 users by simply dual stackingservers, configuring IPv6 DNS records, and procuring IPv6 connectivity. This works — in theory— but it does not necessarily provide an experience that achieves parity with IPv4. In fact, duringthe Internet’s IPv6 transition period, Web sites delivering IPv6 natively will face several keychallenges, including:• Uneven performance. Because the IPv6 Internet is still sparsely connected, native IPv6 communications may require longer, less direct routes than their IPv4 counterparts, resulting in slower performance and higher packet loss. This is particularly troublesome for high throughput or low latency applications such as online gaming or streaming media. In addition, a significant portion of the IPv6 Internet currently relies on tunneling traffic over IPv4, creating additional performance degradation. One recent Akamai performance test involving more than 9,000 nameservers worldwide showed that, on average, network latencies over IPv6 were higher than over IPv4. In North America the difference was particularly pronounced, with a median IPv4 latency of 48 ms compared to a median IPv6 latency of 87 ms, roughly 80% slower. For tunneled IPv6 traffic, the difference in latencies was even more significant. While performance is expected to improve as the IPv6 Internet matures, it may be years before parity with IPv4 is reached.• Reliability issues. The current IPv6 Internet is significantly less reliable, less redundant, and less well-supported that the IPv4 Internet. Indeed, much of it may still be considered experimental, and routes that are broken or incomplete may go undetected for longer periods of time because they are not monitored as closely. Intermittent spikes in IPv6 packet loss are common, undermining the Internet’s ability to provide a robust and high performance platform for Web businesses.• End user denial-of-service. A small but meaningful percentage22 of IPv6-enabled end users will be unable to reach native IPv6 content, due to a variety of factors ranging from browser and OS bugs to broken home gateways, misbehaving routers, misconfigured firewalls, or unreliable tunnels — all ultimately resulting in situations where the end user’s machine believes it has IPv6 connectivity when it really does not. The user’s machine will ask for an IPv6 DNS resolution (also known as a quad-A or AAAA resource record, in contrast to IPv4’s A records), and the name server will return any IPv6 and IPv4 records that exist. The user’s machine will try the IPv6 addresses first, falling back to the IPv4 addresses if those attempts are unsuccessful. The time-out can take 20 seconds per address attempt on Windows, causing untenable delays before the content is delivered. To the end user, it simply appears that the IPv6 site is broken, since all other sites — namely those that do not have AAAA records — continue to work fine. The end result of this is that many content providers are reluctant to hand out IPv6 addresses via AAAA records, even if they have IPv6-capable origin infrastructures. Proposed approaches to this issue — such as whitelisting of DNS resolvers based on IPv6 capabilities, or restricting AAAA responses to resolvers making requests over IPv6 — each have their limitations. Whitelists create significant management and scalability challenges, and restricting AAAA responses can prove troublesome as there is no direct correlation between nameserver IPv6 support and end user IPv6 connectivity. In addition, these approaches require significant work by the content provider to address a very small portion of potential end users.• Lack of IPv6 reporting and analytics. Because IPv6 end user adoption is still in its infancy, the tools for measuring, managing, and understanding IPv6 end user traffic are less mature than the IPv4 equivalents. In order to meet their business requirements, content providers will need logging, reporting, analytics and auditing solutions that can support their IPv6 traffic.
IPv6: What the Transition Means for Content and Application Delivery 8Finally, as content providers plan their IPv6 transition strategy, they need to be aware that currentmarketplace support of IPv6 is uneven, and vendor claims of IPv6 compatibility can be misleading.In addition, the specifications themselves are still evolving; since RFC 2460, there have been morethan two dozen RFCs published relating to the core IPv6 protocols, along with many more relatingto addressing, routing, and other IPv6-related topics.23 Another important issue is performance:IPv6 “support” often does not mean performance parity with IPv4. For example, hardware vendorsmay process IPv4 packets in dedicated hardware while performing the same IPv6 processing in soft-ware, impacting both speed and throughput. The same issue holds true for IPv6 content delivery:it is easy to “support” IPv6 traffic, but doing so with the same reliability and performance as IPv4traffic is far more difficult.Akamai: Helping our customers make the IPv6 transitionFor over a decade, Akamai has transformed the unpredictable, best-effort Internet into a robustand reliable platform for transacting e-commerce, distributing rich media, and delivering enterpriseapplications. Our goal is to enable the best possible end user experience while insulating contentproviders from the underlying complexities of delivering over a highly dynamic and heterogeneousnetwork of networks. In the case of IPv6, this means minimizing the impact of the IPv6 transitionon both content providers and end users. Akamai aims to do this by enabling Web sites to maintaintheir IPv4 origin sites for as long as they wish — while enabling them to reach both IPv4 and IPv6audiences quickly and reliably over the hybrid Internet.As we have seen, providing effective IPv6 support in the context of content and application deliverypresents significant challenges. The naïve approach of simply dual stacking servers and procuringIPv6 connectivity works in principle — but fails to address the critical issues of performance andreliability. We now take a look at the work Akamai is doing to help its customers solve thesechallenges, followed by a phased plan for the rollout of Akamai’s IPv6 services.Under the covers: Key areas of Akamai IPv6 development and innovationWith tens of thousands of servers distributed across a worldwide network infrastructure, enablinghigh performance IPv6 support across the Akamai EdgePlatform is no small task. It involves notonly obtaining IPv6 connectivity across thousands of locations and dual stacking tens of thousandsof servers, but also upgrading Akamai’s mapping, monitoring, routing, logging, communications,and control infrastructures, among others. Here are a few critical pieces to the puzzle:Native IPv6 Support in the EdgePlatformRather than developing an IPv6 proxy or adaptation layer, Akamai is implementing native dualstack IPv6 support within its HTTP EdgePlatform. This means servers will be able to serve bothIPv4 and IPv6 requests as appropriate, ensuring that IPv6 support is well-integrated into presentand future Akamai capabilities.
IPv6: What the Transition Means for Content and Application Delivery 9Mapping the IPv6 InternetLeveraging the unique vantage point of its broadly distributed network and performancemonitoring infrastructure, Akamai is ideally positioned to map the IPv6 Internet, just as it hasdone over the last decade with the IPv4 Internet. Akamai has been making significant invest-ments across its mapping system to better understand the topology and connectivity of theIPv6 Internet and relate it to the existing IPv4 Internet.Understanding the evolving topology of the IPv6 Internet requires significant research,including iterative surveying and mapping efforts. Compared to the existing commercialuse of IPv4, IPv6 is not as well monitored or supported, resulting in more “brokenness”and instability than we typically see in IPv4.Understanding the Performance of the Hybrid InternetThe ability to provide a fast and reliable end user experience will require not only a mapof the IPv6 Internet, but an accurate understanding of real-time connectivity and perform-ance conditions across the IPv4 Internet, the IPv6 Internet, and interconnection points be-tween them. Thus, Akamai is augmenting its intelligent, real-time monitoring and mappinginfrastructure to encompass the entire hybrid Internet. This capability is critical in orderto make the best possible decisions about which server, route, and protocol to use foreach end user request.For example, Akamai’s research indicates comparative end user performance over IPv4vs IPv6 varies on a user to user basis. In some cases, the IPv6 route performs significantlybetter. But in many cases, the IPv4 connection may perform better because the IPv6 connec-tion must go through a tunnel, a congested gateway, or an indirect route, for example.In other instances, for certain IPv6-capable users, the data center where the closest Akamaiservers are deployed may not currently provide IPv6 connectivity. Those end users may alsobe better served over IPv4 from the nearby location rather than being served from an IPv6-capable location that is farther away. On the other hand, as the IPv6 Internet matures, IPv6latencies are expected to drop and begin to outperform IPv4 more regularly. This meansa comprehensive and real-time understanding the performance of the hybrid Internetis necessary to deliver the best possible end user experiences.Making the IPv6 Internet ReliableThe Akamai EdgePlatform was architected from the ground up with principles of recovery-oriented computing at the forefront, enabling the network to operate seamlessly, evenin the face of multiple failures at all levels, from machine to data center to network-wide.24This highly fault-tolerant architecture is necessary in a highly dynamic environment like theInternet — and even more so in the immature IPv6 Internet, where ongoing failures area fact of life. Akamai is investing significant resources to extend its high-availability architec-ture to work effectively across the hybrid Internet, enabling the EdgePlatform to deliverreliably to every end user, every time.
IPv6: What the Transition Means for Content and Application Delivery 10Akamai’s IPv6 services: Simplifying the transitionBy embedding intelligent IPv6 support into its EdgePlatform, Akamai aims to insulate customersfrom the headaches and challenges of a protracted IPv6 transition period. Akamai will enablecustomers to reach their end users over the hybrid Internet quickly and reliably during all stagesof the transition, without having to make significant changes to their origin networking infrastructure.We will be rolling out IPv6 support for our HTTP-based services in three phases, designed to givecustomers a seamless and low-risk approach to undertaking the transition.Early Adoption PhaseThe first phase of Akamai’s IPv6 delivery will enable customers to experiment with IPv6 withless risk and without investing significant time and resources. End users will be able to accessthe customer’s site over IPv6 through a separate hostname, such as ipv6.example.com. The originsite does not need to provide any IPv6 connectivity, as Akamai will deliver to end users overIPv6 while connecting to the origin over IPv4.This means content providers can offer native IPv6 support without spending the time or moneyneeded to hire expertise, set up and manage separate IPv6 servers, procure IPv6 connectivity, recon-figure DNS infrastructure, or train technical support staff — all just to address what is currently a verysmall percentage of the user base. Instead, by simply leveraging Akamai’s experience and economiesof scale, sites can deliver IPv6 services without significant additional overhead.Moreover, the use of a separate IPv6 hostname allows Web sites to begin understanding theirIPv6 audience in a controlled manner, without significantly disturbing their existing productionsite. This means content providers can begin experimenting with and understanding how IPv6will affect their site, enabling them to find and fix application issues — such as headers, log lines,or authentication mechanisms that rely on IP addresses—without affecting users on their primarysite. In addition, they have the opportunity to verify that their site management tools, log analytics,firewalls, and other systems work properly in an IPv6 environment. Early Adoption Phase Benefits • No changes to origin server / origin infrastructure • Native IPv6 delivery to IPv6 users (avoids problems caused by CGN) • Performance and reliability benefits of Akamai’s distributed network • Gain visibility into performance and demographics of IPv6 audience Akamai EdgePlatform www.example.com IPv4 IPv4 client IPv4 .com xample www.e IPv4 AT) en via N Origin IPv4 IPv4 (oft ipv6.example.com IPv6 client IPv6Figure 2: In the Early Adoption Phase, content providers can begin to test and understand IPv6 withoutchanging their origin infrastructure and without affecting existing users.
IPv6: What the Transition Means for Content and Application Delivery 11During this phase, customers will be also able to use beaconing to gain visibility into theIPv6 capabilities of their user base. By embedding an invisible pixel within the HTML of theirIPv4 site that makes a request to the IPv6 site, content providers can learn what percentageof their current user base has working IPv6 support, as well as how many may run into IPv6end user denial-of-service issues.Akamai’s Early Adoption IPv6 support will be offered as a Tech Preview to select customersin the first quarter of 2011. The Tech Preview will support selected traffic management,object delivery, whole site delivery, and application acceleration functionality for customersof Akamai’s Global Traffic Management (GTM), Dynamic Site Accelerator (DSA), DynamicSite Delivery (DSD) and Electronic Software Delivery (ESD) services.End User Transition PhaseIn the second phase, Akamai will enable high performance delivery of content and applica-tions from any IPv4 origin site to all of its end users across the hybrid Internet. As with thefirst phase, the content provider does not need to make significant changes to the originnetworking infrastructure; Akamai communicates with the origin over IPv4, while handlingeach end user request in a seamless and optimized way over the appropriate protocol.For example, when a dual stacked user makes a request to the customer site, the Akamaimapping system will determine whether that user can best be served over IPv6. If so, theuser will receive the IPv6 address of an optimal server as well as the IPv4 address of an opti-mal server. The end user machine will then be able to retrieve content quickly from a nearbyAkamai server over the protocol of its choice. If Akamai determines that the end user is bestserved over IPv4, then only IPv4 addresses will be returned. This allows users to receive theircontent over direct, high performance routes from optimal servers, regardless of protocol. End User Transition Phase Benefits • Deliver best performance and quality of service to all end users (IPv4 and IPv6) • Seamlessly weather the IPv6 transition with no changes to origin networking infrastructure • Avoid CGN, tunnels, indirect routes, and other performance and reliability bottlenecks • Unified analytics and intelligence across global audience base Akamai EdgePlatform www.example.com IPv4 IPv4 client IPv4 www.example.com IPv4 IPv4 or IPv6 depending Origin IPv4 IPv6 client on anticipated performanceFigure 3. In the End User Transition Phase, content providers can leverage Akamai to provide highperformance delivery to both IPv4 and IPv6 users without having to make changes to the originnetworking infrastructure.
IPv6: What the Transition Means for Content and Application Delivery 12Akamai also aims to reduce the risks associated with having a dual stacked origin that uses bothIPv4 A and IPv6 AAAA DNS records (i.e., the aforementioned end user denial-of-service problem),by conservatively taking multiple performance metrics into account in order to avoid deliveringover IPv6 to users with broken or poorly performing IPv6 connectivity.Customers will opt-in to this phase, so that IPv6 end users won’t show up in log lines or forwardrequest headers until the customer has validated that their applications and systems are ready.As with the first phase, small changes may be needed in customer applications that utilize IPaddresses in headers, log lines, or authentication mechanisms. Beyond this, content providersare able to simply maintain their existing IPv4 sites while enjoying fast, reliable delivery to theiraudience base, no matter what stage of adoption IPv6 is in.With today’s slow growth and adoption of IPv6 by end users, the need for content providersto use IPv6 in a commercial production setting will vary based on their particular business needsand demands. Akamai has scheduled its IPv6 readiness roadmap to meet customer needs basedon our current projections of adoption. We anticipate having Beta service available in 2H 2011,with Limited Availability in 1H 2012.Origin Transition PhaseEventually, after IPv6 matures, content providers will move their origin servers to being eitherdual stacked, or possibly even IPv6-only. Akamai will enable its customers to make this transitionon the customer’s schedule, without suffering significant limitations on their ability to deliver thebest possible experience to their end users. Content providers can make the switch when theyare fully ready and when they have access to a more mature marketplace of IPv6 solutions fromhardware and software vendors. Regardless of when this happens, Akamai will continue deliveringtheir content to their audience base over the best-performing routes. Origin Transition Phase Benefits • Continued industry-leading performance, reliability, and scalability to all end users (IPv4 and IPv6) • Provide seamless origin server transition to IPv6—no impact to end users • Leverage Akamai experience and best practices to streamline transition Akamai EdgePlatform www.example.com IPv4 IPv4 client IPv4 or IPv6 www.example.com IPv4 or IPv6 IPv4 or IPv6 depending Origin IPv4 IPv6 client on anticipated or IPv6 performanceFigure 4. In the Origin Transition Phase, Akamai will support IPv6 origin infrastructures. By using Akamai,content providers can delay making this shift for as long as needed.
IPv6: What the Transition Means for Content and Application Delivery 13ConclusionWith ready availability of IPv4 addresses coming to an end, IPv6 adoption will be criticalto the continued growth and success of the Internet. Despite the fact that current enduser adoption levels are very low, forward-looking content providers will want to startexperimenting with IPv6 and developing their transition strategy.During the IPv6 transition period, Web-enabled businesses will face significant challengesin providing the same high quality experience for their IPv6 users as they do for their IPv4users. In addition, they will be understandably hesitant to invest a lot of infrastructureresources to support a very small portion of their current user base. These issues havehindered IPv6 adoption to date.Akamai’s IPv6 services are aimed at helping to smooth and accelerate the IPv6 transitionby making it seamless for Web sites and end users alike. Using its proven EdgePlatform,Akamai will enable sites to deliver exceptional experiences to end users across the hybridInternet—without requiring disruptive changes to their origin networking infrastructure.This will enable companies to deliver high quality, high performance content and applicationsto both IPv4 and IPv6 connected users.As Internet growth continues, IPv6 has a critical role to play to ensure the availablyof addresses for new users and applications. Web-enabled businesses will need to ensuretheir applications are available over IPv6 in order to provide the best possible experienceto the Internet’s ever-expanding audience. Through the use of innovative technologyand service, Akamai aims to help customers with this critical transition.For more information about IPv6-enabled content and application delivery services fromAkamai, please contact your sales team or use the Contact Us link on www.akamai.com.