IPv6: Enabling True Mobile Convergence; Are always-on, fixed, 3G mobile services close to reality? - Wireless

Telecommunications, Feb, 2002 by Mitch Lewis

Next-gen network architectures will overturn the traditional concepts of fixed, mobile, voice and data communications. They will be based on multiservice backbones capable of carrying any type of service over any infrastructure, enabling true convergence of the multiple, separate services that dominate communications.

IPv6 is a major step toward making IP a viable platform for true multiservice, carrier-class networks. IPv6 was developed by the IETF to satisfy the requirements of future converged IP applications. It was designed to enable the performance and service capabilities required by the new mobile infrastructure (including packet-based and 3G networks), broadband networks and next-gen terminals, and to simplify interoperability and network management.

With the next generation of IP-based services, including packet-based and 3G mobile applications, video-on-demand, interactive gaming and VPNs, users will no longer need to endure time-consuming dial-up and log-on routines: Their devices will be always on.

Today, IP addresses are assigned dynamically as users log on. Always-on capability means this "cheat" is no longer available: Every device needs its own permanent IP address. Even before the mobile Internet, the reservoir of addresses with IPv4 was running low. IPv6 enables a staggering 340 billion billion billion billion (3.4x1038) unique addresses (compared with IPv4's 4 billion addresses), guaranteeing a globally unique IP address for each device for many years to come.

IPv6 has a strict hierarchical address system with small routing tables, allowing IP backbone designers to create a flexible, expandable, efficient routing hierarchy. Backbone routers do not need to store route table information on the reachability of every subnetwork, which simplifies the management and update process in what likely will be very large subnetworks, IPv4 has already started using CIDR (classless interdomain routing), which enables route aggregation and simplifies routing tables significantly.

IP does not provide a high level of QoS, and prioritizing different services and ensuring efficient delivery of real-time applications such as voice and video is a challenge. IPv6 offers a wider range of QoS functions, including bandwidth reservation and delay bounds.

IPv6 carries a traffic-flow identification field and a traffic class byte to support simple differentiated services. In addition, a flow label in the IPv6 packet header can be used to distinguish traffic flows for optimized routing. The flow label enables packets that need special handling to be identified, for example, informing routers that a certain amount of latency is required for video or audio streaming, or for assigning a specific level of security. While many operators are opting for ATM as the underlying network technology where detailed QoS is needed, IPv6 is a major step forward for optimizing native IF QoS.

A new level of network management is required, given the heightened complexity of multiservice networks with a common IF core that hooks up to PSTN, GSM, Internet and corporate LAN networks. In an IP environment it is essential to monitor connections, jitter, packet loss and delay. These issues become particularly important for real-time services such as voice and video. Fault management systems must generate alarms before the service quality is affected.

IPv6 allows autoconfiguration and renumbering of routers, which significantly reduce maintenance and expense. In addition, the routing hierarchy with its reduced routing tables minimizes operational workload.

With the growing volume of corporate data and high-value services handled by multiservice networks, security is a major consideration, especially when this information can be accessed by wireless devices anywhere in the coverage area. Traffic must be authenticated, authorized and protected end to end.

IPv6 has built-in data security capabilities based on flexible header extensions, ensuring that a packet actually is coming from the host indicated in the source address. This safeguards against packets with forged source addresses--one of the most common forms of intrusion. Encryption headers enable interoperable payload encryption in IP packets. Security headers can add a level of safety at the network level and be used directly between hosts.

Mobile networks have very stringent requirements for scalability, QoS and security. Standardization of IPv6 has reached a point where it is ready for commercial service and is being promoted through industrial forums of major operators and vendors.

Within a 3G network, IP has two main purposes. User-level IP provides communication between mobile devices and application hosts. Transport-level IP provides communication between network nodes in the mobile infrastructure. The two layers can use different connectivity protocols or IP versions. Workforces are becoming increasingly mobile, and enterprises are allowing their employees to log on to the company intranet from anywhere. IP needs to reflect this change in usage pattern.