Hi,
There are many possible choice for a soft transition of the Service Provider:
- Dual-Stack
The SP can run both protocols in the backbone for a while so he can test IPv6 Service by switching some part of the Network to IPv6 Only and see if it is OK. In case there is a problem he can get back to dual-stack, fix the issue and resume its testing until it is Ok and he can allow IPv6 Only.
- It is possible to provide IPv6 Service without upgrading the backbone to IPv6 Immediately using 6RD if the backbone is IPv4 or 6PE /6VPE (I did the dev-test for 6PE and 6VPE for CISCO for 3 years) if the backbone is IPv4/MPLS. This way the SP can start providing both IPv4 and IPv6 without upgrading the backbone. He can then move slowly to IPv6 with a Dual-Stack period not to switch immediately to IPv6 and allow to fallback if soething is not properly configured to work in IPv6 Only.
With 6VPE, the customer benefit of a dual-stack VPN and recently, CISCO has improved the Support of Multicast in MPLS which was main weakness of MPLS based solutions.
Once the SP has migrated to IPv6 Only, it is still possible to offer dual-stack, IPv4 and IPv6 service to its customers using DS-Lite or better, A+P when it will be available as A+P (dIVI-pd based) does not rely on CGN which has a couple of drawbacks for the SPs.
Once the Customer has migrated to IPv6 Only, it is also still possible to access some IPv4 resources (Networks, servers, applications) using NAT64.
I have a presentation for you:
http://www.slideshare.net/fredbovy/transition-to-ipv6-and-security
And you will find more on my page:
http://www.fredbovy.com
I will be glad to help you further.
Fred Bovy
15 years ccie #3013
18 years ccsi #33517 (former #95003)
IPv6 Forum Gold Certified Engineer
IPv6 Forum Gold Certified Trainer
Email: fred@fredbovy.com
Web: http://www.fredbovy.com
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