Chris Metz

Transition from IPv4 to IPv6: A State-of-the-Art Survey

In the process of Internet evolution, the transition from IPv4 to IPv6 has become inevitable and fairly urgent. IANA (Internet Assigned Numbers Authority) has finally exhausted the global IPv4 address space, which leaves the community no choice but pushes forward the IPv6 transition process. IPv4 and IPv6 networks both will exist during the transition period, while the two are not compatible in nature. Therefore it is indispensable to maintain the availability, as well as to provide the inter-communication ability of IPv4 and IPv6. Years ago a series of transition techniques were actually proposed. However, because of their technical immatureness, they failed to cover the solution space well. Some of these techniques were even obsoleted by IETF due to their flaws. This paper reconsiders the basic problems and key difficulties in IPv4-IPv6 transition, and introduces the principles of tunneling and translation techniques. Then the paper surveys the mainstream tunneling and translation mechanisms raised since 1998, especially the new mechanisms proposed recently, capturing the aspects of technical principles, pros and cons, scenarios and applicability. Recommendations on mechanism selection for different scenarios are provided. Moreover, the paper looks into the characteristics and transition requirements of practical ISP networks, and proposes the usage and deployment strategy of the transition mechanisms in both backbone and edge networks.

The Transition to IPv6, Part II: The Softwire Mesh Framework Solution

For pt.1 see ibid., p.54-59 (2005). This work spawned an effort in the IETF to develop a generalized method for routing and tunneling different address families across uniform IPv4 or IPv6 backbone networks. Inspired by the CERNET2 effort, the IETF softwires working group has introduced a framework for a solution that offers a generalized, network-based capability for routing and tunneling multiple address families across native IPv4 or IPv6 backbone networks

4over6: network layer virtualization for IPv4-IPv6 coexistence

IANA exhausted its IPv4 address space in 2011, and IPv6 is the next generation to replace IPv4. However, the IPv6 transition techniques are still immature and holding back the development of the next-generation Internet. Hence, IPv4-IPv6 coexistence is becoming increasingly imminent. During the coexistence period, the Internet will consist of IPv4-only, IPv6-only, and dual-stack segments. Both the network infrastructure and operations must support IPv4-only, IPv6-only, and dual-stack accordingly. This article develops a 4over6 virtualization architecture that virtualizes IPv4-only networks over IPv6-only networks. This architecture enables two IPv4- only segments to communicate over an IPv6-only network by using an IPv4-in-IPv6 tunnel. The architecture can be examined in different areas such as addressing schema, layer 3 routing, and packet forwarding. The 4over6 virtualization architecture is being standardized in IETF. Various implementations and deployment scenarios are actively discussed in the ISP and vendor communities.

Beyond MPLS ... Less is More

Multiprotocol label switching possesses a simple data plane that has enabled new services and functions operating in many service provider networks. Yet, the MPLS control plane can impose both technical and operational challenges. This article explores these challenges and examines recent advances in IP routing technology suggesting that all services - including those that are MPLS-based - can be delivered over networks running only IP.

Multiprotocol label switching and IP. Part 2. Multicast virtual private networks

For pt.1 see ibid., vol.9, no.3, p.68-72 (2005). Part I of this series discussed a solution for running multiprotocol label switching virtual private networks (MPLS VPNs) across a service providers native IP network. Yet, MPLS VPNs support only unicast routing, whereas many of the enterprise customers that use the service run applications that require IP multicast. This article examines multicastVPN (mVPN), which provides the ability to support IP multicast across MPLS VPNs. Service providers can thus offer IP VPN services that support unicast and multicast applications.

COLAP: A predictive framework for service function chain placement in a multi-cloud environment

Network function virtualization (NFV) over multi-cloud promises network service providers amazing flexibility in service deployment and optimizing cost. Telecommunications applications are, however, sensitive to performance indicators, especially latency, which tend to get degraded by both the virtualization and the multiple cloud requirement for widely distributed coverage. In this work we propose an efficient framework that uses the novel concept of random cloud selection combined with a support vector regression based predictive model for cost optimized latency aware placement (COLAP) of service function chains. Extensive empirical analysis has been carried out with training datasets generated using a queuing-theoretic model. The results show good generalization performance of the predictive algorithm. The proposed framework can place thousands of virtual network functions in less than a minute and has high acceptance ratio.