Download Problems in China Telecom

Problem Statement of
China Telecom
Guoliang YANG
[email protected]
2017/5/25
Problems and Challenges for
China Telecom
1. Address Pool Exhaustion
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2. Protocol Incompatibility
Predicted extinction date
Worldwide
2010.10
Asia
2012.8
China Telecom
2013.3
CT status quo ( Unit: million )
Total Space
1
Motivation
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Different protocol Packet format
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Different treatment for software
2
Technology
91
Exhausting speed 17per yr
4. Lack of transition experience
Giant network scope and large
numbers of service platforms need
Considerable human and material
resources
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4
Deployment
No practical criteria referenced
for IPv6 transition
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3. Inactive Industry Chain
3
Environment
ICP
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For network management, product development
and service flow, no mature experiences and
examples can be learned from.
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Government
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Network
Customer
No clear guidelines from government
No drivers for ICP
Users do not care
Long Life cycle of ROI
(ROI, Return on Investment)
Contents
application
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IPv4 Contents Transition
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Transition Technology Selection
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network
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Problems in deploying Dual Stack
 NAT444 authentication
 User tracing
 Impact on internet application
Problems in deploying tunnels
 incapable multicast service in Ds-lite
Problems in deploying protocol translation
 Infeasible fixed range port in DIVI
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users
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Address planning strategy
Unavailable PPPoEv6 in Windows XP
Transition Technology Selection

Considerations which need to be made when applying
various transition technologies to existing networks.
Various transition technologies may have different
impacts to the services:
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Dual Stack with Carrier Grade NAT444
Tunnel technologies
Protocol Translation
Problems in deploying Dual Stack
Carrier Grade NAT444: Authentication

Single-Sign-On of the website：
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The user’s IPv4 private address is allocated by BRAS after AAA process, so, only
user's private ipv4 address is mapped with the user account in AAA system. In
some cases, website may make SSO authentication with user’s IP address via
carrier’s AAA server.
User accesses the Internet website with public address, while the address in the
carrier’s AAA Server is private address. So the user can not be authorized.
VPN authentication

In L2TP and NAT444 environments with user creating VPN itself, if the user
wants to access the enterprise internal network via VPN, some authentication
protocol such as EAP, may not be supported in these two environments.

AAA authentication
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In some cases, dual stack users may establish dial-up sessions to BRAS to get
IPv4 and IPv6 address separately.
BRAS may probably send different radius authentication request packets to AAA.
According to current anti-attack policies in AAA server, the AAA server will deal
with the first request packet and ignore the other ones.
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Problems in deploying Dual Stack
Carrier Grade NAT444: User tracing
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Flow Analysis System and Behavior Analysis System
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The existing Flow Analysis and Behavior Analysis System of Carrier is centralized
and deployed in backbone. In NAT444 environment, they both need to be placed
before NAT device, in order to collect users’ data and analysis their behavior
accurately by their IPv4 address.
Problems in deploying Dual Stack
Carrier Grade NAT444: Others

Internet user access the private network users
initiatively. Currently two access methods are
considered in the metropolitan area network:
Communication between Private IP host, the traffic will
not go through NAT444 device.
 Communication between Private IP host and Public one,
the traffic will go through NAT444 device.
For the user who wants to visit a website which is provided
by private address host, it is not accessible.
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NAT444 doesn’t support the current PPTP VPN.
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Problems in deploying tunnel
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What is the sequence of deployment for tunnel
technologies:
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6RD、DS-lite and L2TP, etc
6RDDS-lite or directly to DS-lite?
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Incapable multicast service in DS-Lite:
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For China Telecom, the IPTV multicast replication point is located in BRAS.
There is a trend to move down the replication point to access node.
In the DS-Lite scenario, the IPTV multicast replication point will be at AFTR
which will lead some performance problems and conflict with the above
trend.
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What is the investment benefit and maintenance cost of
different tunnel technology?
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Problems in deploying protocol translation
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Infeasible fixed range port in DIVI
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DIVI assigns a fixed range of ports to the HG, for
users sake, it is infeasible and unfair for customers.
Much larger traffic will pass the DIVI gateway
than other technology
Address Planning Strategy
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When IPv6 is deployed, how to plan the IP
address pool in a large scale network is a
problem.
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IPv4 Contents Transition
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Lacking business driven and technology driven for IPv4
Internet contents Providers (ICP) to provide IPv6
contents. For example, the lifecycle of online games is
short and deploying IPv6 has long lifecycle of ROI.
(Return on Investment)

ICPs need carriers’ guidelines or solutions about the
IPv4 contents transition.

How ICP can provide IPv6 services with the least
changes?
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Thank you
2017/5/25