Case studies on IPv6 deployment Sample
In this report, the deployment and the strategies used for the deployment of IPv6 has been discussed. Two companies, namely COMCAST and AT&T have been considered to discuss the deployment of IPv6. A comparison of the strategies used by these companies in the way of deploying the IPv6 in their system has been done.
In Comcast, the cable modems use IP addresses and are managed by those addresses, unlike the DSL modems.
During the first phase certain types of directly connected CPE were supported, where a single computer is directly connected to the cable modem. Critically, the approach used by them is "native dual stack" that means that the customers will use both IPv4 and IPv6 addresses. However, it is likely that the other ISPs which are less prepared would be using tunnelling or a large scale NAT in the network. With the launch of Comcast's IPv6, it was considered to be reliable and high performance CMTSes from Arris. Comcast continued working with the vendors of another network equipment so as to ensure production grade. The support for IPv6 was available to all of the Comcast customers.
AT&T recognizes the potential of IPV6, is committed to a thorough testing of its capabilities, and has embarked upon a phased implementation plan to deploy IPv6 throughout its global network infrastructure over the next several years. The IPv6 has been adopted as a strategy by industry, which is backed by the policies of the government in some of these countries. Over the past 18 months, these efforts made a significant inroad in the way of validating IPv6 applications in multimedia and peer-to-peer (P2P) areas involving new categories of IP-aware devices (1).
The Internet Engineering Task Force (IETF) is a large, volunteer international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and its smooth operation. This organization is responsible for the primary technologies that make the Internet possible. Internet drafts, called Request for Comments, or RFCs, are the working documents of the IETF. As an indicator of the interest level in IP version 6, a search of published RFCs at http://www.rfc-editor.org reveals that there are 106 draft standard papers written for IP version 6 and various sub-topics related to the protocol. This is a notable amount of activities around the topic when one considers that BGP (Border Gateway Protocol), the routing protocol used by every single router on the internet today, yields only 47 results using the same search.
The IETF standards track is a progression of a standard document's progression through much iteration of development and peer review. The process begins with "Proposed Standard" and moves to "Draft Standard", before finally becoming an "Internet Standard". An Internet Standard is considered the final authority for development. Often vendors will implement protocols in hardware and software long before they have reached the final phase. In fact, vendors have frequently implemented protocols with no accompanying standard. It is considered better to follow standards to facilitate interoperability between vendors.
The original standard for IP version 4 was initially published in September 1981, as RFC 791 by Jon Postel. In December 1995, RFC 1883 proposed new standard for the Internet Protocol called IP version 6. (IP Version 5 was a real-time streaming protocol, which never materialized). RFC 2460 (1998) is the latest version to define the IPv6 standard.
An IP packet is comprised of a header and payload. The header is like an envelope that is addressed to a destination. The header also has many other functions such as signifying the priority level of the packet, the sending source, and the application type. Each machine, it passes through must universally understand all of the portions of the packet header. At every machine, the header is inspected to make forwarding decisions about the packet and to apply priority policy or security policy. RFC 2460 defines the IPv6 packet header format, extension headers and options. The RFC also covers flow labels, packet sizes, traffic classes and the effect of IPv6 on upper layer protocols. The header format is illustrated in Figure 7: IPv6 Packet Header.
This new and improved header format provides the pathway to greater functionality for this next generation protocol. In particular, it is the source and the destination address length, the flow label and the traffic class fields that provide for the majority of new features.
It is expected that IPv6 will coexist with IPv4, for a large duration. The constraint for the new network and its deployment here is the exhaustion of IPv4 address space. This will adversely affect the existing installations of IPv4 that requires more IPv4 addresses or access to the resources of IPv6 (2). With the improvement and expansion in the addressing capacity, inherent security and features of mobility, IPv6 can be considered as a significant improvement over the current protocol. It facilitates new developments focused on end-to-end communication models.
Here we have chosen two companies to compare their strategies of using IPv6. The two companies that are chosen:
COMCAST: The cable modems use IP addresses and are managed by those addresses, unlike the DSL modems. Earlier to manage cables, Comcast used Net 10 (RFC1918), but later that space got out dated or exhausted in 2005 and from then, Comcast was provided with a very large portion or rather a block of public IPv4 space for its management.
But later it was realized that IPv6 would be the best solution to deal with the problems
AT&T: AT&T recognizes the potential of IPV6, is committed to a thorough testing of its capabilities, and has embarked upon a phased implementation plan to deploy IPv6 throughout its global network infrastructure over the next several years.
With the growth of the global Internet, must its overall architecture should be evolved to provide space for the new technologies that will support the increasing numbers of applications, users, appliances, and services.
Hence, IPv6 is designed so as to meet the growing requirements and to allow a return to the environment globally where the rules of addressing the network will be transparent to the applications (3).
The address space of the current IP isn’t able to satisfy the large increasing number of users or the geographical needs of the expansion of the Internet, the requirements of the increasing new applications namely personal digital assistants (PDAs) that are Internet-enabled, integrated telephony services, home area networks (HANs), Internet-connected automobiles, and distributed gaming. IPv6 turned some network address bits from 32 bits (in IPv4) to 128 bits, which in turn will provide more globally unique IP addresses for each and every network device. The incorporation of unique IPv6 global addresses will simplify the mechanisms used to reach and to provide end-to-end security for network devices, crucial functionality to the applications and the services that increase the demand for the addresses.
Techniques such as address reuse with translation and temporary-use allocations have been used to extend the lifetime of IPv4. Although these techniques are going to improve the address space and satisfy the setup of traditional client-server, they are unable to meet the requirements of the emerging applications. The need for always-on environments (such as residential Internet through broadband, cable modem, or
Ethernet-to-the-Home) to be contactable precludes these IP address conversion, pooling, and temporary allocation techniques, and the “plug and play” required by the consumer’s further increases the requirements for addresses. The flexibility of the IPv6 address space helps to provide the support for the private addresses, but the use of Network Address Translation (NAT) should be reduced because addresses are widely available globally. The end-to-end security and quality of service (QoS) were reintroduced by IPv6, which are unavailable throughout an NAT-based network.
The following benefits are provided by IPv6:
- Larger address space is provided to reach globally and scalability
- A Simple header for the process of routing efficiency and performance
- Policies for network architecture flexibility and deeper hierarchy
- Efficient support for routing and route aggregation
- Server-less auto-configuration, easier renumbering, multi-homing, and improved plug and play support
- Mandatory IP Security (IPsec) supported for all devices
- Enhanced support for Mobile and mobile computing devices
- Improved multicast support with increased number of addresses and efficient mechanisms
They were in the early stages of the deployment of IPv6 with the availability of some IPv6 applications in the market and the first router products required creating a trade-off among the available IPv6 services. The main focus of the products was on the techniques of migration and transition that are required for the deployment, rather than on meeting the requirements of the high levels of traffic (4).
However, the success of IPv6 will ultimately depend on the accessibility of applications that operate over the IPv6. The benefit of IPv6 design is its ability to integrate into and coexist with the existing networks of IPv4.
The four key strategies for deploying IPv6 are as follows:
- Deployment of IPv6 over IPv4 tunnels: The IPv6 traffic will be encapsulated by these tunnels within the IPv4 packets, and are primarily used for communication between the sites that are isolated with IPv6 or provide a connection to the remote IPv6 networks over a backbone of IPv4. The techniques such as using manually configured tunnels, semiautomatic tunnel mechanisms such as tunnel broker services generic routing encapsulation (GRE) tunnels, and mechanisms of the fully automatic tunnel such as IPv4-compatible and 6to4 are involved.
- Deployment of IPv6 over dedicated data links: In this technique isolated IPv6 domains are enabled to communicate by using the same infrastructure as used for IPv4, but with IPv6 a separate Frame Relay or ATM PVCs, dense Wave Division Multiplexing (DWDM), or separate optical links will be used.
- Deployment of IPv6 over MPLS backbones: in this technique, the isolated IPv6 domains are allowed to communicate with each other, by using an MPLS IPv4 backbone. Though multiple techniques are available in the network at several points, but little change to the backbone infrastructure or reconfiguration of the core routers is required because forwarding is done by using labels instead of the IP header itself.
- Deployment of IPv6 using dual-stack backbones: with this technique the applications of IPv4 and IPv6 are allowed to coexist in a dual IP layer routing backbone. All the routers in the network are required to be upgraded to dual-stack with IPv4 communication by using the protocol stack of IPv4 and IPv6 communication using the IPv6 stack.
Eventually, as IPv6 is going to become a protocol of choice, these legacy IPv4 system mechanisms will be allowed to be a part of the overall IPv6 network. The translation between the IPv4 and IPv6 protocols of the end system, or on a dedicated server, or on a router within the IPv6 network, and, together with dual-stack hosts is done by using these mechanisms, A full set of tools provides for the incremental deployment of IPv6 without and disruption in the IPv4 traffic.
The cable modems use IP addresses and are managed by those addresses, unlike the DSL modems. Earlier to manage cables, Comcast used Net 10 (RFC1918), but later that space got out dated or exhausted in 2005 and from then, Comcast was provided with a very large portion or rather a block of public IPv4 space for its management.
But later it was realized that IPv6 would be the best solution to deal with the problems (5).
IPv6 technical trials are being conducted in their production network for more than a year, and they have been diligently working on the deployment of IPv6 for over 6 years. After a long period of challenging preparatory work, investment in significant technology, development of internal skills, and close collaboration with their technology partners, they announced that they have achieved a new critical milestone in the transition to IPv6 — they started deployingIPv6 in the pilot market to customers in selected areas (6).
During the first phase certain types of directly connected CPE were supported, where a single computer is directly connected to the cable modem. Critically, the approach used by them is "native dual stack" that means that the customers will use both IPv4 and IPv6 addresses. However, it is likely that the other ISPs which are less prepared would be using tunnelling or a large scale NAT in the network. These approaches are likely to result in breaking or slowdown of some applications (such as some real-time applications). The approach Native dual stack helps in reducing the chances of breaking or slowing down of applications, and it maintains a better and faster broadband Internet experience.
Finally, it can be considered to be the start of pilot market deployments as opposed to full national deployment. However, it cannot be said that this will be without technical bugs in the near term. The focus lies in the identification of any issues in final IPv6 transition and fixing them rapidly so that they can begin a national deployment.
Now the pilot market deployment of IPv6 has been started by them that are the first phase in the several phases for the deployment of IPv6. Certain types of directly connected CPE are directly supported, where a computer is connected directly to a cable modem. The cable modem will be responsible (a subset of DOCSIS 3.0 cable modems, which will expand over time) and the operating system will also be responsible (only Windows 7, Windows Vista, Mac OS X 10.7 / Lion), such that it must support stateful DHCPv6.
However, it may seem to be a small step, but their incremental approach was based on starting the deployment now and progressively expands it over time. This helped them to ensure if the transition is orderly and stable, and the performance of IPv6 is as expected. In the later phases home gateway devices (Apple, D-Link, Netgear, etc.) were supported as well as their commercial fibre-based customers.
It would be worthwhile to note that they were deploying native dual stack, by which the customer will get to use both IPv6 and IPv4 addresses. In other words, they were not using the tunnelling technology or Network Address Translation (NAT). If Used a tunnel, it would have resulted in additional overheads as compared to the using of native IPv6 as the traffic must be traversed a relay before reaching the destination and back. However, the NAT technologies are based on two layers of NAT, one for the home (in a home gateway device), and the other one within the network of the service provider a single IPv4 address across possible hundreds of customers or more are shared. Moreover, by Using NAT, several challenges may be posed as compared to not using NAT because the traffic has to traverse an NAT device before reaching the destination and back. In addition, it was notified that those two layers of NAT will result in the breaking of a number of applications that were important to the customers (7).
In contrast, of using the tunnelling and large scale NAT, native dual stack, possibly reduces the breakdown or slowdown of applications and always maintain a faster and better broadband Internet experience.
The support for IPv6 was launched by COMCAST for the home networking enabled customers; it was the second of the two phases of their initial rollout of IPv6. This phase was built on the basis of their earlier work where IPv6 support for standalone computers was enabled. By enabling the support for IPv6 in the areas in which it was launched for home networking customers (those using a home gateway / router), the customers were able to take advantage of and begin using IPv6. The launch of customer home networking enabled by IPv6 was also critical to their participation in the Launch of World IPv6.
With the launch of Comcast's IPv6, it was considered to be reliable and high performance CMTSes from Arris. Comcast continued working with the vendors of another network equipment so as to ensure production grade. The support for IPv6 was available to all of the Comcast customers. In particular, they were working closely with Cisco and expected that their CMTS platform will be ready soon to support the IPv6, reliably and at scale in production so that the deployment can be expanded beyond their Arris CMTS footprint.
With this milestone, Comcast provided foundationally IPv6 support for which they expected to expand and evolve over time. The initial launch of IPv6 customer home networking supported the allocation or delegation of an IPv6 prefix that was by default /64 in length. Based on their testing and the capabilities of today's devices, it was felt that allocating prefixes of this length will balance the earlier deployment of IPv6 with the help of advanced deployment configurations for the home networking. They continuously worked in the way of enhancing their support for the customers of home networking for IPv6 that began later in 2012. As the deployment for the nationwide rollout in 2012 was evolved, they planned to update the allocations of IPv6 in order to provide shorter prefixes that were based on the service and/or devices in use by the subscribers of the company, as well as the prefix size their device requests. They tried to offer a range of shorter prefix lengths that were important for the customers, as this would enable multiple networks and several exciting potential new services for home networking.
The support for Native dual stack remained central to the deployment of IPv6 in Comcast; this means that the customers who are having IPv6 for home networking will be provisioned with IPv6 in addition to IPv4. This approach allowed them to avoid the use of other types of transition technologies like tunnel and large scale Network Address Translation (NAT) in the near term. The experience and the best practices of the industry continued to suggest that the best path to a seamless IPv6 transition and optimal customer experience is offered by the native dual stack, which is paramount to Comcast.
The measurements of the updated IPv6 Launch network operator for November 2013 were available in the usual place. Comcast is continuously making rapid progress with the rollout of their IPv6 that can be evidenced by the strong growth trend over recent months.
AT&T recognizes the potential of IPV6, is committed to a thorough testing of its capabilities, and has embarked upon a phased implementation plan to deploy IPv6 throughout its global network infrastructure over the next several years.
To date, EU countries, Japan, China, Korea and India founded increasing difficulties in obtaining sufficient allocations of IPv4 address. Due to some historical reasons, the IPv4 address allocation is unevenly distributed in the favour of the U.S. These countries consider the deployment of IPv6 as a fresh start and a way to distribute IP addresses properly and equitably. Also, the IPv6 has been adopted as a strategy by industry, which is backed by the policies of the government in some of these countries. Over the past 18 months, these efforts made a significant inroad in the way of validating IPv6 applications in multimedia and peer-to-peer (P2P) areas involving new categories of IP-aware devices (1).
From the perspective of the U.S. mobile operator, as long as operators assign private IP addresses to the terminals and public addresses to elements of the network, the shortage of ipv4 was thought not to be a significant concern for the coming some years. The recent advances in technology of mobility and trends of emerging user application have highlighted the value of IPv6 for operators of mobile and the costs of not adopting IPv6 [8,9].opportunity. Real-time IP multimedia communications and emerging P2P applications have infused new thinking with the mobile terminal devices about how to leverage the best and to ensure the continued growth in enabling mobile device data.
The IPv6 visibility in U.S. public policies has been recently elevated. The response of U.S. government’s concern for cyberspace security, the promotion of North American IPv6 Task Force (NAV6TF) end-to-end IPsec based on IPv6 is a process for attainable security solutions. The expansion of its recommendations  calling for IPv6 deployment in the U.S. Government for a national business, economic, social and political reasons, starting with the U.S. Department of Defense (DoD) (8).
The advantages provided by it that has enabled innovative applications, which can leverage the demand for global public IP addresses by potential billions of mobile devices. In the following sections we consider these reasons to transition to IPv6:
- Exhaustion of ipv6
- Mandates of government
- Functional improvements of ipv6
- Leveraging of IPv6 for the new applications
Major improvements over IPv4 can also be seen in IPv6 that may benefit mobile IP and fixed network providers and network users whether enterprise or consumer. The key features of IPv6 are highlighted below:
Stateless Address Auto-Configuration is supported by improving Network Management, IPv6 that can significantly simplify efforts of the operator in configuration and management of fixed and mobile terminals (‘Plug-and-Play'). Auto-Renumbering of routers and terminal devices on the sites that are based on time-scoped public IPv6 addresses also facilitates the consolidation of the network.
The support of Native IPsec in IPv6 helps in enabling a robust end-to-end security for applications. Embedded encryption and authentication mechanisms are provided by IPsec (Encapsulated Security Payload and Authentication Header) for both TCP and UDP, which is even more secure than SSL.
In addition to Layer 2 of mobility management in the wireless network, Mobile IP can provide Seamless uninterrupted IP sessions via Fast Handovers and Binding Updates between the home address and the care-of address as the mobile terminal roams into a foreign network. The need for the Foreign Agent with auto-configuration and neighbour discovery by the mobile host can be removed by Mobile IPv6 in the foreign network. It also supports the routing of the forwarded traffic directly to the mobile host, (i.e. Avoidance of triangular or ‘trombone’ routing). For seamless handovers, Mobile IP is required where users change the access to the technologies, e.g. 3GPP to WLAN.
Route aggregation capability similar to the classless inter-domain routing (CIDR) in IPv4 is incorporated in IPv6 routing. The Unicast and Multicast routing of IPv4 have been extended with any cast routing capabilities.
The main feature worthwhile to note is its virtually limitless address space with 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses that are available with IPv6 compared to approximately 4 billion with IPv4. This will help in providing persistent public IP addresses to a virtually unlimited number of always-on devices including PCs and mobile phones and the emerging types of devices such as sensor networks and intelligent infrastructures. The integrated support of IPsec helps in deploying the capabilities which can be leveraged for improved security.
The adoption of IPv6 as the next generation protocol is required by the IPv4 public address space exhaustion so as to deliver IP services across the global internet. The transition to IPv6 was considered to be a gradual process which may take 3-4 years to execute in a transparent fashion. However, because of the exhaustion of IPv4 and the lack of support for IPv6 by vendors and carriers, the plan to adopt IPv6 was pushed out horizon of planning for most organizations. The risks associated with not adopting IPv6 were sooner elevated due to this fact and the lack of expertise around IPv6.
The Consulting department of AT&T provides a full suite of consulting services for IPv6 to assist customers with readiness and transition to IPv6. These services reflect the full life cycle of IPv6 in way of enabling the customers to engage the company in a flexible manner:
- IPv6 Readiness Assessment
- IPv6 Strategy and Architecture
- IPv6 Design and Engineering
- IPv6 Testing and Piloting
- IPv6 Transition Planning
A readiness assessment to be performed in an organization is the first and the most urgent need for IPV6 transition. This assessment helps to identify the impact of the IPv6 on different aspects of the environment and the costs and impacts of the adoption of IPv6 will be defined as it relates to overall asset and service provider readiness/compliance for supporting IPv6. The infrastructure elements such as routers and switches are provided by the Equipment vendors and the operating systems for PCs are in different phases of the readiness of IPv6 and aligning product refresh cycles with IPv6 readiness is critical. The Consulting services of AT&T provide an inventory of elements and use cases which are impacted by IPv6.
IPv4 and IPv6 protocols are totally independent protocols, and the environment supporting IPv6 will initially consist of islands of IPv4, IPv6 and dual stack IPv4/IPv6 components. Emerging technologies will be required for interconnecting these islands namely ISATAP, Taredo, GRE tunnels, 6to4 tunnels and IPv6/IPv4 translation. Moreover, the schemas for addressing, integration with DNS/DHCP, and dual homing architecture with internet carriers must be addressed. The Consulting services of AT&T provide the customers with an architectural framework for the integration of IPv6 in different phases within the current IPv4 environment and strategy for the deployment of IPv6 within the enterprise (9).
The AT&T Consulting service provides designs and expertise in the field of engineering so as to address the configuration and integration aspects of IPv6 architecture in detail. The main objective of this service is to focus on the development of the configurations of equipment, test plans and integration plans that are required to integrate the elements into an IPv6 environment. Detailed configuration and integration parameters are provided by the consultants for each element impacted by the integration of IPv6.
AT&T Consulting service may assist the customers with the deployment of lab environments for the concept testing as well as pilot deployments to educate the IT staff and validate the integration. These types of environments are developed for testing the functionality and integration of IPv6 into the legacy IPv4 environment.
The AT&T Consulting service also helps in the development of an overall plan for governance and the schedule for integration, which can be utilized for ensuring a seamless transition to IPv6. Development of the overall transition schedule is also included in the integration planning, resources and tasks encompassing inputs from the teams defined under the program governance model.
Comcast was not using the tunnelling technology or Network Address Translation (NAT). The reason behind this was that it would have resulted in additional overheads as compared to the using of native IPv6 as the traffic must be traversed a relay before reaching the destination and back.
On the other hand, AT&T was using the tunnelling technology for the deployment of IPv6 through IPv4. Hence, as compare to Comcast, AT&T was incurring more expenses than before because of incorporation of the tunnelling technology.
In contrast, of using the tunnelling and large scale NAT, native dual stack, possibly reduces the breakdown or slowdown of applications and always maintain a faster and better broadband Internet experience. Thus, Comcast was experiencing a reduced level of breakdown or slowdown of applications. Whereas AT&T was using a tunnelling technology that ultimately results in a breakdown or slowdown of applications.
Native IPsec in IPv6 helps the AT&T in enabling a robust end-to-end security for applications. Embedded encryption and authentication mechanisms are provided by IPsec (Encapsulated Security Payload and Authentication Header) for both TCP and UDP, which is even more secure than SSL.
With the deployment of IPv6, the end to end security prevails in the organization as a whole, but with the use of native dual stacks, the security level of AT&T was higher than the Comcast.
With the large number of available IP addresses, the scalability of the company increases, but if we compare these two companies, then it would not be wrong to say that the scalability in Comcast was more than the AT&T.
After measuring the performance, it would not be wrong to say that most of the major network operators all over the globe have worked a lot in the deployment of IPv6 for their subscribers, and a measurable increase in the volumes of IPv6 traffic can be seen at large aggregation points. The growth of this IPv6 traffic reflects that IPv6 will be the dominant Internet protocol within six years.
All of these measurements indicate that IPv6 deployment is happening at scale and in a global fashion. A very long tail of web content and services is there that is not capable of IPv6 yet, and many more networks are there that have to be deployed, but with the available data, we suggest that these challenges need to be addressed rather than despairing them. Anybody and it cannot predict the future is true especially when it is related to the future of the Internet, but for IPv6 deployment at least, the signs are promising.
Comcast observed that,
- 96 more bits, no magic
- Deployment problems are not at layer 3 but at layer 7 & 8
- Engaging vendors early helps
- Training & early Operation engagement are important steps
AT&T recognizes the potential of IPV6, is committed to a thorough testing of its capabilities, and has embarked upon a phased implementation plan to deploy IPv6 throughout its global network infrastructure. The exhaustion of IPv4 address space is inevitable, driven by increasing demands for public IP addresses for always-on mobile terminals, as well as other Internet devices and applications. Government initiatives on IPv6 are advancing on a number of fronts. New IPv6 applications are beginning to emerge to leverage the functional improvements available with IPv6, and these applications will grow as the IPv6 network infrastructure becomes more widely available.
AT&T has been involved for some time with testing and trials of IPv6 technology. Based on this experience, AT&T has established architecture for IPv6 and is deploying equipment to support IPv6 technology today. AT&T plans to launch commercial IPv6-based service offerings in 2009 with Dual Stack IPv4/IPv6 AVPN introduced in 2/09 and Dual Stack IPv4/IPv6 MIS by YE 09. AT&T is committed to supporting our enterprise customers when they decide the addition of IPv6 capabilities is appropriate for them.