1. Applying IPv6 to LTE Network
Deoknyong Ko
New Connectivity TF
Network Technology R&D Center
SKtelecom

2. What’s the first things that pops into your mind when you hear the word, Korea?

3. What’s the first things that pops into your mind when you hear the word, Korea?

4. Which country invented the Internet
for the first time in the world ?
Which country was next ?

5. Which country invented the Mobile IPv6 Internet
for the first time in the world ?
Which country was next ?

6. What’s the first things that pops into your mind when you hear the word, Korea?

7. ※ The Market Share of Mobile Subscribers in Korea
LG U+
SKtelecom
50.5%
Wired Broadband
Mobile Platform
Semiconductor KT

8. Contents
Background
IPv6 Transition Schemes
FAQ

9. Contents
Background
IPv6 Transition Schemes
FAQ

10. Korean Status in The Past
Germany
France
United States
Romania
Japan

11. Korean Government’s Encourage
Subject　
Company　
Networks
Date
Operator
SKtelecom
On Commercial '
SKbroadband
On Field Trial ’ KT
Preparing
LGU+
(Only Voice)
Portal
Naver
Daum
Nate

12. Summary of Applying IPv6
Subject　
Purpose　
Networks
Transition Scheme
Date
Subscribers
Wired
Field Trial
HFC, G-PON
Dual Stack
’ 　
1 thousand　
Wireless
Commercial
LTE
Only IPv6 '
670 thousands　
※ Subscribers by Jan. 2015
IPv4
Networks
Dual Stack
(IPv4/IPv6)
Only IPv6
Networks
IPv4
Networks
Only IPv6
Networks

13. Why Did SKT Decide to
Adopt IPv6 ?

14. ※ Reference: http://www.google.com/intl/en/IPv6/index.html
Why Did SKT Decide to
Adopt IPv6 ?
CapEx for NAT equipment
∙ LTE device has 2 different IPv4 addresses by default in SKT.
∙ The number of connected device could exponentially increase.
※ Reference:

15. Why Did SKT Decide to Adopt IPv6 ?
Difficult to operate duplicated networks

16. ※ The statistics of IPv6 users. (http://6lab.cisco.com/stats)
Why Did SKT Decide to
Adopt IPv6 ?
Korean government’s encouragement
※ The statistics of IPv6 users. (
Norway
Belgium
Germany
United States

17. Which Networks to be migrated IPv6?
Applying IPv6 to only primary networks.
Legacy network will be replaced to LTE or G-PON.
Subject　
Networks
Applying IPv6
Note
Wireless
LTE O
Commercial
WCDMA X
Wi-Fi
Wired
G-PON
Field Trial
HFC
xDLS

18. Contents
Background
IPv6 Transition Schemes
FAQ

19. Access Networks (LTE EPC)
Summary of IPv6 Transition Schemes
Subject　
Transition Schemes
Backbone
Dual Stack
Access Networks (LTE EPC)
NAT64, 464XLAT

20. Transition Scheme for Backbone
We don’t even need to apply Only-IPv6 to the backbone.
Dual stack can support both IPv4 and IPv6 access networks.
There is no issue.

21. Transition Scheme for Access Network
Case#1: IPv6 is enabled on contents server
(End-to-End IPv6 connectivity)
Case#2: IPv6 is not enabled on contents servers

22. Transition Scheme for Access Network (contd)
Case#1: IPv6 is enabled on contents server
(End-to-End IPv6 connectivity)

23. Transition Scheme for Access Network (contd)
Case#2: IPv6 is not enabled on contents servers
SKT should support
that only-IPv6 subscribers can connect to
only-IPv4 contents server.
NAT64, DNS64

24. Algorithm of NAT64, DNS64 ① Customer tries to connect to www.naver.com
② LTE device asks DNS64 server what is an IP address of
③ DNS64 server responds ‘64:ff9b::
④ LTE device tries to connect to ‘64:ff9b::
⑤ NAT64 translate IPv6 packet to IPv4 packet

25. Drawback of NAT64 Algorithm
Some applications are Hard Coded as only IPv4 address instead of domain name.
∙ IPv6 LTE device doesn’t ask DNS64 server.
∙ Only IPv6 LTE device can’t interpret an IPv4 address.
Error occurred !!

26. 464XLAT Overview
RFC 6877, “464XLAT: Combination of stateful and stateless translation” (Information Track)
Provided by Android OS by default
T-Mobile USA and SKT adopted

27. 464XLAT Architecture 464XLAT has two operations, CLAT and PLAT Subject
Full Name
Customer-side translator
Provider-side translator
Location
In cellphone
In operator’s network
Translation
IPv4  IPv6
IPv6  IPv4

28. 464XLAT Operation LTE device has 3 outgoing interfaces Subject
Source Address
Data
Packet
LTE Data
Original
Allocated from P-GW (e.g. 2001:290::1)
CLAT
“ ” (dummy IPv4 address)
“LTE data interface ::464” (e.g. 2001:290::464)
Voice
LTE IMS
Allocated from P-GW (e.g. 2001:2b8::1)

29. 464XLAT Operation (contd)
If android OS find a hard coded for IPv4 address( ), android OS will transfer packet via CLAT interface.
CLAT
PLAT
( )
Content Server
( )
Src:
Dest:
Src:
Dest:
Src:
Dest:
Src: 2001:290::464
Dest: 64:ff9b::
Src: 2001:290::464
Dest: 64:ff9b::

30. Verify 464XLAT Schemes
Verified 15 hundreds applications while preparing the commercial service.
A few applications have trouble due to customer’s circumstance.

31. Contents
Background
IPv6 Transition Schemes
FAQ

32. Which handset OSs and models are supported an IPv6 service?
∙ We applied to only android OS not iOS.
∙ We applied to Galaxy Note 4 first. (‘ )
∙ We have applied to all new devices including tablet since then.

33. Do you support IMS service(VoLTE) also?
∙ Of course.
∙ We support an IPv6 service of LTE Data and LTE Voice.

34. Do you support international roaming service?
Do you support Wi-Fi service?
∙ Not yet.
∙ We don’t have a plan to launch now.

35. Do you support tethering service?
∙ Yes.
∙ LTE device allocates an IPv4 address not IPv6 address to laptop.

36. Do you satisfy the quality of IPv6 data and IMS service compared to IPv4 ?
∙ Yes.
∙ We can’t find the quality difference between IPv4 and IPv6 service.

37. Can I know about the increase of IPv6 users and IP deployment since commercial service ?
∙ I’m sorry but, I can’t inform that.
∙ IPv6 users and the CapEx for IP deployment are restricted document.

38. Can I know about the increase of IPv6 traffic since commercial service ?
∙ Recent IP equipment(ex> Router, P-GW) can’t distinguish between IPv4 traffic and IPv6 traffic.

39. Do you inform your customers that they are serviced by IPv6 ?
∙ No.
∙ Our aim is that our customer can’t recognize which service is provided.

40. How to utilize the collected Public IPv4 addresses ?
∙ Private IPv4 addresses were used to VoLTE Service.
∙ We are currently allocating Public IPv4 addresses to VoLTE service to raise voice quality.

41. Do you have a plan to launch the new BM based on IPv6 ?
∙ Yes.
∙ We are developing the cellular based IoT Service (ex> MTC, NB CIoT).