Overview on I Pv 6 in 3GPP networks David Kessens <david ...

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30 Ιουν 2012 (πριν από 5 χρόνια και 1 μήνα)

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Overview on IPv6
in 3GPP networks
David Kessens <david.kessens@nsn.com>Introduction
• A quick refresher: Mobile networking and IP
• Current support in Nokia and Nokia Siemens Networks
products
• Common problems
• Conclusion
2 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610A quick refresher: 3GPP network
User’s IP plane
GTP tunnel
Application
S G S N G G S N
RNC
S erver
C ore Network
UTRAN
Transport IP plane
• User and transport planes are completely independent, i.e. the transport plane can
run on a different IP version than the user plane
• UTRAN and Core Network transport can theoretically run on different IP versions
• More info in: draft-korhonen-v6ops-3gpp-eps-03.txt
3 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610PDP Context
S ame PDP (IP) address and APN
G G S N
IS P X
PDP C ontext X (APN X, IP address X, QoS )
1 1
PDP C ontext X2 (APN X, IP address X, QoS 2)
PDP C ontext selection
S G S N
based on TFT (downstream)
IS P Y
G G S N
PDP C ontext Y (APN Y, IP address Y, QoS)
PDP C ontext Z (APN Z, IP address Z, QoS )
IS P Z
4 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610
APN Z APN Y APN X3GPP and Dual-Stack bearer management logic
• Internet Access Point can be configured as: IPv4v6, IPv4-only, or IPv6-
only
• When IPv4v6 is configured: if a handset and a network both actually
support IPv4v6 type of bearer, it will be used, otherwise parallel IPv4 and
IPv6 bearers may (Rel-8) or shall (Rel-9) be activated
• Parallel bearers are needed when:
• Legacy SGSN downgrades IPv4v6 requests to IPv4 requests
• Network knows mobile may handover to network (segment) not
supporting IPv4v6 type of bearers (ESM cause #52 “only single stack
allowed” is returned)
• Applications see similar dual-stack access in either cases
• Network can always reject IPv4v6 and force single stack bearer, either
IPv4 or IPv6
– ESM cause #50 (IPv4-only allowed) or #51 (IPv6-only allowed)
When IPv6-only is configured, fallback to IPv4-only is needed in case of
roaming network is not supporting IPv6 type of bearer
5 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610IPv4/IPv6 address family selection
• A phone is provisioned with parameters for bearer
establishment:
if a bearer is IPv4-only or IPv6-only, there’s no choice
• If a phone is provisioned with dual-stack bearer, but an
application, a peer, or both are IPv4-only or IPv6-only, there
is no choice either
• Only when an application, a network, and a peer are all dual-
stack, a selection between IPv4 and IPv6 address families
can be made
• Operating system can prefer IPv4 or IPv6. Commonly IPv6 is preferred, but
sometimes IPv4
• Middleware software, e.g. runtime environments, can alter OS’s preferences
• Applications can alter preferences of OS and/or middleware
6 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610Dual stack access via handset
10.0.0.2
IPv4v6
• Dial-up:
IPv4v6 PDP
Internet
PPP
(PC gets the
IPv4 address and
2001:0db8:1::/64
the IPv6 prefix of
the PDP)
NAPT &
DHC P
server
192.168.0.2
192.168.0.1
10.0.0.2
IPv4v6
IPv4v6 PDP
IPv4v6
Internet
LAN
• C ellular Router:
2001:0db8:1::/64
IPv6 ND
2001:0db8:1::/64
(PC gets an IPv4
Proxy
address from a
handset implementing
NAPT. IPv6 address is
Additionally for IPv6, DHC Pv6
Prefix Delegation (R FC 3633) is
configured from proxied
introduced in 3GPP release-10
/64 prefix (R F C 4389).
7 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610State of IPv6 support in Symbian
• An application can use IPv4 or IPv6 PDP contexts but not
both (easily)
– In WLAN native dual-stack is supported for an application
– One application can be using IPv4 PDP context while another uses
IPv6
• With help of HTTP proxy or NAT64/DNS64, access to IPv4
domain can be provided over IPv6-only 3GPP connection
IPv4
IPv4
Internet
Internet
NAT64
DNS64
IPv6 Core
IPv6 Core
IPv6 PDP
IPv6
GGSN
IPv6
Internet
Internet
Nokia
5230
Customer 8 confidenti a l IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610
8IPv6 support in Maemo (MeeGo) devices
• Maemo devices are currently IPv4-only
– Maemo community originated IPv6 add-on has been recently made
available that enables dual-stack in 3GPP and WLAN accesses for
N900 for testing purposes
– Instructions are here: http://n900-ipv6.garage.maemo.org/
• IPv4 and IPv6 PDP contexts can be opened for the same or
different APNs With help of HTTP proxy or NAT64/DNS64,
access to IPv4 domain can be provided over IPv6-only 3GPP
connection
IPv4
IPv4
GGSN
Internet
Internet
IPv4 PDP
IPv6 PDP
IPv6
IPv6
Internet
N900
Internet
Customer 9 confidenti a l IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610
9Flexi Network Gateway IPv6 Capabilities
Current Release 2H/2010
2011
IPv6 features
IPv6 features IPv6 features
• IPv6 PDP context & EPS bearer and Dual-
• DHCP support
• Dual-Stack
Stack IPv4/v6 EPS bearer
for prefix
PDP Context
• L3-L7+ Service awareness and DPI for IPv4 &
delegation and
(R9)
IPv6
stateless
• ePDG
• GRE tunneling and dynamic & static routing,
DHCPv6
support
including support for OSPFv3
parameter
including
• Dual-Stack APN
configuration
IPv6 type
• Parameter configuration using PCOs
• Partial IPv6
bearers and
(DNS[46], etc)
support on the
transport
transport plane
• IPv4/IPv6
• L2TP
interworking
10 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610Deployment status
• We are now getting focused on deployment:
– Handset and network device support for IPv6 exists for many years
▪ Transition technologies did not get as much attention
– For example: Tušmobil, T-mobile USA, TeliaSonera
• Despite the positive news, we still need more deployment &
regular user exposure to hash out all issues!
– Different transition approaches might we warranted
– Scaling and software issues are to be expected
11 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610Common problems
• Business case is relatively hard to explain
– what is the true cost of lower Internet traffic/size growth compared to
an Internet with less NAT ?
• Most deployments so far were the initiative of one or a few
enthusiastic individuals without permission from higher up
– is this good enough to get started ?
The good news: the impending IPv4 run out seems to be a
wakeup call for many players
12 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610Common problems
• Packet forwarding is easy, but network management can be
problematic
– other people in organization are ignorant about IPv6: no process, no
system support
– examples:
▪ provisioning for subscriptions stopped ipv6 service at TeliaSonera during
live test deployment
▪ should a user always get the same prefix ?
• IPv4 to/from IPv6 interworking needs more practical
experience with regular end users
13 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610Conclusion
• Dual stack is preferred, but … :
– customer mix is different for different operators
– customers with relatively simple access profile (web, mail) might be
entirely satisfied with ipv6 only access
– dependency on capabilities of customer handsets
– dual stack PDP context can come at a cost from a resources
perspective but solution is not far away
• Network and handset vendors are ready
– we have experience now with small groups of customers, need more
experience under load and with more ‘average’ users, especially
regarding IPv4 to/from IPv6 interworking technologies
– large installed base of legacy handsets
• IPv6 education/knowledge throughout most organizations is
still relatively low
14 IPv6 on 3GPP networks: a brief overview / Google IPv6 Implementers Conference / Mountain View / 2010610