2015.5.6

Deoknyong Ko (engineer@sk.com)

Broadband Tech Lab

Network Technology R&D Center

SKtelecom

What’s the first things

that pops into your mind

when you hear the word, Korea?

What’s the first things

that pops into your mind

when you hear the word, Korea?

※ The Market Share of Mobile

Subscribers in Korea

SKtelecom

50.5% KT

LG U+

Wired Broadband Mobile Platform Semiconductor

Background

IPv6 Transition Schemes

Contents

FAQ

Background

IPv6 Transition Schemes

Contents

FAQ

Summary of Applying IPv6

Subject Purpose Networks Transition Scheme

Date Subscribers

Wired Field Trial HFC, G-PON Dual Stack ’12.5.29 1 thousand

Wireless Commercial LTE Only IPv6 '14.9.25 670 thousands

IPv4 Networks

Dual Stack (IPv4/IPv6)

Only IPv6 Networks

IPv4 Networks

※ Subscribers by Jan. 2015

Only IPv6 Networks

Why Did SKT Decide to Adopt IPv6 ?

Why Did SKT Decide to Adopt IPv6 ?

CapEx for NAT equipment

※ Reference: http://www.google.com/intl/en/IPv6/index.html

∙ LTE device has 2 different IPv4 addresses by default in SKT. ∙ The number of connected device could exponentially increase.

Difficult to operate duplicated networks

Why Did SKT Decide to Adopt IPv6 ?

NetworkA

NetworkB

NetworkA

NetworkB

PDN-GW#1

PublicNetwork

PDN-GW#2

Korean government’s encouragement

Why Did SKT Decide to Adopt IPv6 ?

※ The statistics of IPv6 users. (http://6lab.cisco.com/stats)

United States

Norway

Germany

Belgium

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 X

Wired

G-PON O Field Trial

HFC X

xDLS X

Contents

Background

IPv6 Transition Schemes

FAQ

Summary of IPv6 Transition Schemes

Subject Transition Schemes

Backbone Dual Stack

Access Networks (LTE EPC)

NAT64, 464XLAT

Transition Scheme for Backbone

Dual stack can support both IPv4 and IPv6 access

networks.

There is no issue.

We don’t even need to apply Only-IPv6 to the

backbone.

Dual Stack(Backbone)

IPv4 Access Networks

(WCDMA, Wi-Fi)

IPv6Access Network

(LTE)

PublicNetwork

Case#1: IPv6 is enabled on contents server

(End-to-End IPv6 connectivity)

Transition Scheme for Access Network

Case#2: IPv6 is not enabled on contents servers

PDN-GW

Dual StackNetwork

LTE Device(Only IPv6)

Dual Stack

Only IPv6

Case#1: IPv6 is enabled on contents server

(End-to-End IPv6 connectivity)

Transition Scheme for Access Network (contd)

Transition Scheme for Access Network (contd)

Case#2: IPv6 is not enabled on contents servers

PDN-GW

PublicNetwork

NAT64

DNS64

LTE Device(Only IPv6)

Only IPv4

Only IPv4

SKT should support that only-IPv6 subscribers can connect to

only-IPv4 contents server. NAT64, DNS64

Algorithm of NAT64, DNS64

PDN-GW

PublicNetwork

NAT64

DNS64

LTE Device(IPv6-Only)

IPv4-Only

IPv4-Only

① Customer tries to connect to www.naver.com

② LTE device asks DNS64 server what is an IP address of www.naver.com

③ DNS64 server responds ‘64:ff9b::www.naver.com’

④ LTE device tries to connect to ‘64:ff9b::www.naver.com’

⑤ NAT64 translate IPv6 packet to IPv4 packet

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 !!

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

464XLAT Architecture

464XLAT has two operations, CLAT and PLAT

Subject CLAT PLAT

Full Name Customer-side translator Provider-side translator

Location In cellphone In operator’s network

Translation IPv4 IPv6 IPv6 IPv4

464XLAT Operation

Subject Interface Source Address

Data Packet

LTE Data Original

Allocated from P-GW (e.g. 2001:290::1)

CLAT “192.0.0.4” (dummy IPv4 address)

“LTE data interface ::464” (e.g. 2001:290::464)

Voice Packet

LTE IMS Allocated from P-GW (e.g. 2001:2b8::1)

LTE device has 3 outgoing interfaces

464XLAT Operation (contd)

If android OS find a hard coded for IPv4 address(1.2.3.4),

android OS will transfer packet via CLAT interface.

CLAT PLAT

(5.6.7.8) Content Server

(1.2.3.4)

Src: 192.0.0.4 Dest: 1.2.3.4

Src: 2001:290::464 Dest: 64:ff9b::1.2.3.4

Src: 2001:290::464 Dest: 64:ff9b::1.2.3.4

Src: 5.6.7.8 Dest: 1.2.3.4

Src: 5.6.7.8 Dest: 1.2.3.4

Verify 464XLAT Schemes

Verified 15 hundreds applications while

preparing the commercial service.

A few applications have trouble due to

customer’s circumstance.

Background

IPv6 Transition Schemes

Contents

FAQ

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. (‘14.9.24)

∙ We have applied to all new devices including

tablet since then.

Do you support IMS service(VoLTE)

also?

∙ Of course.

∙ We support an IPv6 service of LTE Data

and LTE Voice.

Do you support international

roaming service?

∙ Not yet.

∙ We don’t have a plan to launch now.

Do you support Wi-Fi service?

Do you support tethering service?

∙ Yes.

∙ LTE device allocates an IPv4 address not

IPv6 address to laptop.

LTE Device(IPv6 Address)Laptop

(IPv4 Address)

PublicIPv6 Network

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.

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.

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.

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.

Do you launch the new BM based on

IPv6 ?

∙ Yes.

∙ We are developing IoT which is capable

of end-to-end IPv6 connection.