Can Applications Benefit From IPv6?
Published: September 6, 2006
The Microsoft Windows Meeting Space feature in Windows Vista (now in beta testing) simplifies common activities faced during business meetings, presentations, and collaborative sessions. The feature relies on Internet Protocol version 6 (IPv6), the protocol developed to address the scalability limitations of today’s Internet. As we describe in this article, Windows Meeting Space gains many advantages from its use of IPv6. Moreover, available transition technologies ensure that this mainstream application can safely rely on IPv6 on existing networks, long before the protocol is deployed natively.
Overview of Windows Meeting Space
The Windows Meeting Space feature in Windows Vista simplifies common activities faced during business meetings, presentations, and collaborative sessions. The feature allows groups to instantly and securely form a shared, common session. Within this session, users can "project" their desktop or application to other participants or to a Windows Vista compliant network projector, share files with a group in a common work area and jointly edit the file, and pass notes to other session participants.
The following figure shows an example of using Windows Meeting Space to modify a presentation.
Windows Meeting Space operates entirely peer-to-peer, meaning that it can be used on any network, including corporate networks and public hotspots. Where connectivity is not available, the feature automatically creates an ad-hoc wireless network among the meeting participants.
Windows Meeting Space utilizes several services provided by the Windows Peer-to-Peer Networking platform, including:
In addition, the feature uses Web Service Discovery, Windows Distributed File Replication Service (DFRS), and Windows Remote Desktop Protocol (RDP) to respectively support meeting session discovery, file exchange, and desktop/application streaming.
Windows Meeting Space and IPv6
Windows Meeting Space uses Internet Protocol version 6 (IPv6). IPv6 was developed by the Internet Engineering Task Force (IETF) to serve the growing demands of today’s Internet. IPv6 is commonly associated with its large network address range, which was developed to support the exponential growth in the number of Internet-connected hosts and devices and prevent the threatened exhaustion of available IPv4 addresses. However, IPv6 provides several other features, including integrated support for IP security (IPsec) and simplified client address allocation.
By using IPv6, Windows Meeting Space gains several advantages:
Barriers to IPv6 Deployment and Development?
IPv6 support is available on Windows XP Service Pack 1, Windows XP Service Pack 2, and Windows Server® 2003. IPv6 is enabled by default on Windows Vista and Windows Server “Longhorn” (now in beta testing)
Many developers fear relying on IPv6 because it is not widely deployed on today’s Internet. However, as demonstrated by Windows Meeting Space, IPv6 can be used readily by mainstream enterprise and consumer applications.
Over small LANs, IPv6 requires no special network support. Each host automatically selects a link-local IPv6 address, and IPv6 traffic travels freely within most LAN environments. Similarly, over the Internet, hosts also select Teredo IPv6 addresses to operate seamlessly across most consumer home networks and NATs.
Within the enterprise environment, cross-subnet operation requires network-level support for IPv6. Most enterprises are not yet ready to create native IPv6 networks, but various tunneling technologies are readily available to support IPv6 operation over existing IPv4 corporate networks. The Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) enables IPv6-aware applications to co-exist with IPv4 applications and networks. To support ISATAP, many enterprises will not need to do anything special, because enterprise-grade routers support ISATAP. Many enterprises have rapidly enabled IPv6 connectivity by deploying an ISATAP router (supported by Windows Server 2003).
The potential code complexity and developer training were other important considerations in choosing to support IPv6 within the Windows Meeting Space feature. Fortunately, the transition from IPv4 to IPv6 (and indeed from IPv4 to dual IPv4/IPv6 support) proved to be quite straightforward from both perspectives. Support for IPv6 involves relatively minor changes to traditional Windows Sockets development—primarily requiring the use of version-agnostic data structures and explicit support for multiple active host IP addresses. In addition, Microsoft provides a handy Checkv4.exe tool to help catch programming errors that block IPv6 usage.
Windows Meeting Space relies on IPv6 to provide ubiquitous addressing, improved Internet-wide connectivity, and rapid auto-configuration in ad-hoc network environments. Use of IPv6 ensures that the feature can easily take advantage of Quality of Service (QoS) in the future and IPSec within enterprises that mandate its use. Finally, IPv6 future-proofs the feature for deployment within evolving network environments world-wide.
Though many developers have feared relying on IPv6 because of its limited deployment, Windows Meeting Space demonstrates that IPv6-based applications can still operate in existing IPv4 environments by relying on a combination of transition technologies (Teredo, 6to4, and ISATAP) and automatic link-level operation. Most important, IPv6-based applications require no or minimal new network configuration.
As a leader in enabling broad deployment of IPv6, Microsoft is providing full IPv6 compatibility within Windows Vista. Features such as Windows Meeting Space further demonstrate the value and viability of IPv6 in today’s enterprise and Internet environments. Developers should work to make their applications IPv6 aware, joining Microsoft in laying the foundation for the future of networking.
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