IPv6 Deployment Best Practice by China Telecom
Contents1.
Preface................................................................ 2
2.
Stage 1, CNGI Project.................................................. 2
3.
Stage 2, Commercial IPv6 project ....................................... 5
3.1 Phase 1 of Stage 2....................................................... 5
3.2 Phase 2 of Stage 2....................................................... 6
3.3 Current situations....................................................... 6
3.4 Obstacles................................................................ 711. Preface

China telecom’s IPv6 history can be divided into 2 stages:
Stage 1, from 2003 to 2010, the main tasks are technical research,
test bed construction and its pilot, and the main purpose is to test andacquire experience.
Stage 2, from 2011 to 2015, match the period of China government’s
12th 5-year plan, according to NDRC’s IPv6 project schedule, this stage
can be divided into 2 phases:
Phase 1(2011-2013) - Small scale commercial deployment;
Phase 2(2014-2015) - Large scale commercial deployment

2. Stage 1, CNGI Project

China telecom had participated in NDRC’s CNGI(CNGI is China Next
Generation Internet, which is launched by National Development and Reform
Commission (NDRC) of China, together with other seven ministries. CNGI
is a national program for promoting research and development of IPv6 andother new Internet technologies in China.) project in stage 1.
CNGI’s core network has more than 40 GigaPops nodes, covering morethan 20 provinces around China. Meanwhile, it also implements high speed
connection with the international next generation Internet. This highspeed network provides compatible platform for further network
application research and experiment.
CNGI demonstration network is composed of six core networks, accessnetwork/CPN, and Internet exchange center (CNGI-IX). The six corenetworks are built by China Telecom, CERNET, China Unicom, China
Netcom/CAS, China Mobile and China Railcom respectively, but China
telecom takes on a leading role in CNGI construction. The maximum
bandwidth of CNGI backbone network is 10Gbps. The following figure1
presents the topology of CNGI backbone networks, with colored points
according to their conductors. Each operator implements its core networkby its own design, which results in unnecessary GigaPops located within
the same city, like Beijing, Shanghai and Guangzhou.

2Figure1. CNGI Demonstration Core Network
Although those six core networks are built by different telecom
carriers respectively, they are all under the framework of CNGI project.
CNGI program requires that each core network is reachable by the otherone. Internet exchange center is one of the major approaches to realizethat goal. There are two Internet exchange centers in CNGI, which arereferred to as CNGI-IX. The first one is built by CERNET, located inBeijing, and the second one is referred to as CT-CNGI-SHIX, which is builtby China Telecom in Shanghai,. These two CNGI-IXes backup each othermutually. Figure 2 shows the connection between CNGI-IXes and the six core
networks. On the top of providing interconnection, these CNGI-IXes act
as the gateway to the international NGI networks as well.

3Figure2. CNGI-IX connection topology
China Telecom’s CNGI network is called CT-CNGI; the topology isillustrated as Figure 3:

Figure3. CT-CNGI topology
4CT-CNGI has 7 super POPs in 7 major cities of China, including Beijing,
Shanghai, Guangzhou, Hangzhou, Nanjing, Changsha and Xi’An. In addition,
there is a Lab inter-connection among China Telecom’s three subsidiary
Research Institutes.
As mentioned above, CT-CNGI-SHIX (AS38035) is being operated andmaintained by China Telecom. Before 2010, all participants of
CT-CNGI-SHIX (China Telecom, China Mobile, China Unicom, CERNET, BT,SingTel, NTT and KDDI) built eBGP peer with IX-R (AS38035). The topologyof CT-CNGI-SHIX is described as figure 4:

Figure4. CT-CNGI-SHIX topology

3. Stage 2, Commercial IPv6 project

Apart from CNGI, NDRC launched a commercial V6 deployment project inthe end of 2011 for 3 tier 1 ISPs in China (China Telecom, China Unicomand China Mobile), and it is called stage 2.

3.1 Phase 1 of Stage 2
As far as construction scale, in Phase 1(small scale commercialdeployment)，duration is from 2011 to 2013，CT plans to upgrade native
IP backbone(ChinaNet) to support dual stack, upgrading 6PE/6VPEs of MPLS
backbone(CN2) to provide IPv6 VPN service;
At the same time, upgrading and reforming IPv6 infrastructure (BOSS,metro area network, etc.) in 10 provincial branches for fixed network,including 21 MANs (Solutions: Dual stack, NAT444, DS-Lite) and 14 IDCs(Solutions: Dual stack, NAT64);
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For NAT444, it is a solution to solve private IPv4 address shortage
problem, once operators deploy private V4 address widely, IPv6 upgrading
would not be essential, they will lose the motivations on V6 migration.
On contrary, DS-Lite solution is a more positive approach to solve
the IPv6 challenge. DS-Lite only requires the assigning of IPv6 addresses
for users. So the network infrastructure must first be IPv6-enabled.
Therefore, through this way, IPv6 is mandatory, and substantiallyencourages the service providers to deploy IPv6.
In ICP transition scenario, from the operators’ point of view, weprefer upgrading their service to dual-stack. If V4 content can beaccessed by V6 end users via NAT64 gateway without software upgrading andre-coding, ICP will lose their motivations to migrate to IPv6, just likenegative influence of NAT444 in broad band access network scenario.
In terms of the goal of user numbers, CT plans to provide 3 million
real IPv6 end users in fixed network.

3.2 Phase 2 of Stage 2
In phase 2(Large scale commercial deployment ,2014-2015), the maintask of this period is to expand the scale of construction, CN2 upgrade
to fully support dual stack, include all P and PE routers; Finishing IPv6
infrastructure (BOSS, metro area network, etc.) upgrading and reformingin 30 provincial branches for fixed network, including 160 metro area
networks and 70 IDCs.

3.3 Current situations
By the end of June this year, the network infrastructure improvements
is basically completed, including the dual stack transition for all
ChinaNet PoPs, core CR, part of SR dual-stack upgrading in 21 MANs of 10provinces, as well as setting AFTR/CGN function card for hundreds of BRAS.
The 14 IDCs has realized the IPv6 ready through software upgrading,equipment replacing and architecture re-design and so on.
The majority of provincial branches have already realized thebusiness operation support system transition, to support IPv6 end to end
6process for users (opening accounts, resources reservation, service
opening, business activation, fault warning, authentication andbilling).

3.4 Obstacles
The IPv6 function and feature supporting of home gateway is imperfectand immature, need bulk replacement, resulting in costs increasing;Market share of Win 7/8 are still limited, makes a barrier to user
migration;
ICP little transition efforts result in deficient content andservice.
The commercial IPv6 network interconnection is not yet implemented
between the three operators as well as with overseas (ChinaNet, CN2 and21 dual-stacks enabled MANs are isolated IPv6 island at present);
Commercial IPv6 IX must be built as soon as possible.

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