Skip to main content

A sensible mobile IPv6 migration strategy


Listen to the podcast to learn more.

With mobile devices and new applications rapidly moving to support IPv6 and the remaining public IPv4 addresses being rationed, mobile operators need a strategy to migrate their networks to IPv6 - sooner rather than later. But this is easier said than done. In this blog, we’ll discuss a number of the IPv6 network migration alternatives and recommend the best approach for the mobile operator.

There are many obstacles facing mobile operators in migrating to IPv6. These include:

  • A large number of mobile devices, services, and applications that still only support IPv4
  • Network engineering designs using IPv4 addressing that don’t scale
  • Network migration costs in CAPEX/OPEX, time, and personnel
  • Overall migration complexity

While all of the above present significant challenges, the sheer complexity of the task at hand keeps network operations and IT organizations up at night.

How can the network be migrated to IPv6 with the least amount of network disruption that minimizes the CAPEX and OPEX of the operator? Which of the various options provides the best strategy to migrate to an IPv6 network?


The approach many mobile operators have taken is to delay the inevitable. They’re implementing methods that enable IPv4 only, IPv6 only, or IPv4/IPv6 capable devices and application services to peacefully coexist in the network. Often this involves deploying carrier grade network address translation (CG-NAT) routers in the network or implementing a dual-stack IPv4/IPv6 network architecture.

And while these methods work, they don’t achieve the goal of migrating the network to IPv6. These are highly inefficient transition strategies that require a significant capital investment in either new platforms (routers) or upgrades within the core network to support IPv6 or dual stack architectures. Not only is there additional capital cost required to support both IPv4 and IPv6 in the network, but there is on-going operational cost to maintain the network in this mode.


There are better, more sophisticated strategies available that let the mobile operator migrate to IPv6 but still provide support for IPv4 only devices and services.

One alternative that is gaining traction in the industry is to convert the mobile network to IPv6 but also implement 464XLAT (RFC 6877), which provides limited IPv4 access services and connections over an IPv6 network. 464XLAT requires the use of both stateful protocol translation (provider side translation, PLAT) in the core at the CG-NAT64 router and client side translator (CLAT) function, which is stateless protocol translation, in the user equipment (UE). CLAT is being implemented in more mobile devices with both Android and Windows support.

Figure 1. the 464XLAT function in a mobile network.

There are several advantages in implementing 464XLAT over an IPv6 mobile network:

  • Migrating to an IPv6 network simplifies operations and therefore is less costly than supporting IPv4 only or dual stack networks
  • Minimizes the required IPv4 addressing and network resources
  • Reduces the number of CG-NAT routers required in the network
  • Improves end-to-end IP network monitoring
  • Maintains quality of end-user services


Several mobile operators are aggressively migrating their networks to IPv6. This is evident from the deployment status provided by Akamai Technologies and the Internet Society World IPv6 Launch Organization, which shows the top 1000 web sites reachable via IPv6 networks.

It’s also evident from this status that many mobile operators have yet to devise a plan for IPv6 migration. The time is now to take action and develop that plan.


If you would like to learn more about this topic, listen to the podcast or read the white paper IPv6 Migration Strategies for Mobile Networks.


IpV6 Transition web pageIP Mobile Core web page7750 Service Router web page

To contact the author or request additional information, please send an email to

David Nowoswiat

About David Nowoswiat

Dave is a senior product marketing manager at Nokia with over 25 years of telecom and industry experience. Lately he’s been doing his part to help manufacturers in their digital transformation journey. In his spare time Dave plays sports, runs the odd marathon and enjoys good craft beer - not necessarily in that order. Reach Dave at David Nowoswiat | LinkedIn | David Nowoswiat | Google+

Wouter Reynders

About Wouter Reynders

Wouter Reynders has almost 10 years of experience in the IT/Telecommunications industry, with experience in IP/MPLS Network Design & Consulting, Business Development, Solution Consulting and Product Training in various roles during his career at Alcatel-Lucent for the EMEA region. Wouter focuses on Alcatel-Lucent’s IP/MPLS products (Metro Aggregation, IP Edge and IP Core Routing) and service provider solutions in the residential, business and mobile segments. Wouter completed his engineering studies in Gent, Belgium.

Article tags