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Ipv6 in The 3G Network: Confidential
Ipv6 in The 3G Network: Confidential
Ipv6 in The 3G Network: Confidential
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IPv6 for mobile - why??
Address space problem
• Projected over 1 billion mobiles by 2005
• Not enough IPv4 addresses especially in Asia
• Eg-. In China, there 100+ million handsets and far less IP
addresses…
• IPv6 addresses – unique address / addresses
• Eliminate the use of NAT
• Overcome addressing / compatibility problems
Operational advantages – eg stateless autoconfiguration
Mobile IPv6 more efficient, can be used in future
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IPv6 Recap:
New header format
Ver. Traffic Flow Label Ver. Hdr Type of Total Length
Class Len Service
Source Address
Source Address
(128 bits)
Destination Address
Options...
IPv4Header
Destination Address
(128 bits)
IPv6 Header
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IPv6 Recap:
Key changes in IPv6 header
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Text Representation of Addresses
IPv4-embedded: 0:0:0:0:0:FFFF:13.1.68.3
or ::FFFF:13.1.68.3
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General Format of Unicast Addresses
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Configuring Interface IDs
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IPv6 for 3G – How?
Extend GPRS / GTP to handle IPv6 addresses during
PDP setup
Methods to obtain IPv6 address
• Static
• Dynamic
• Stateless
• Stateful – using DHCPv6 (for increased control)
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Dynamic Stateless Autoconfiguration
MT BSS / UTRAN SGSN GGSN
1. Activate PDP Context Request (PDP type = IPv6, PDP Address = empty, …)
7. Neighbor Solicitation
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Recommendations from the IETF
IPv6 WG to 3GPP
Uniqueness: Each prefix must not be assigned to
more than one primary PDP context
Allow 3GPP nodes to use multiple identifiers within
those prefixes, including randomly generated
identifiers
Multiple prefixes may be assigned to each primary
context
Work in progress…
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Types of Transition Mechanisms
Dual Stacks
• IPv4/IPv6 coexistence on one device
Tunnels
• For tunneling IPv6 across IPv4 clouds
• Later, for tunneling IPv4 across IPv6 clouds
• IPv6 <-> IPv6 and IPv4 <-> IPv4
Translators
• IPv6 <-> IPv4
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Transition Scenario –
Dual IPv4/IPv6 Stack
Native IPv4
Network
IPv4 Host
Native IPv6
Network
IPv6 Host
GGSN
Dual Stack
v4/v6 host
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Tunnel and Transition Types (many!)
Configured tunnels - Router to router
Automatic tunnels
• Tunnel Brokers (RFC 3053)
• Server-based automatic tunneling
• 6to4 (RFC 3056)
• Router to router
• ISATAP (Intra-Site Automatic Tunnel Addressing Protocol)
• Host to router, router to host, Maybe host to host
• 6over4 (RFC 2529)
• Host to router, router to host
• IPv64
• For mixed IPv4/IPv6 environments
• DSTM (Dual Stack Transition Mechanism)
• IPv4 in IPv6 tunnels etc….
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Transition Scenario –
Tunneling Options Diagrams - Gopinath Rao Sinniah, AIMST
IPv6 IPv4
Network Network IPv6
Network
RBS
GGSN
IPv6 IPv6
host host
IPv4 IPv6
Network Network IPv4
Network
RBS
GGSN
IPv4 IPv4
host host
v4/v6
IPv4 PDP Routers Practical transition; within backbone constraints
Context
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Network Address Translation - Protocol Translation
(NAT-PT)
IPv6 IPv4
IPv4 Pool: 120.130.26/24 Network Network
IPv6 prefix: 3ffe:3700:1100:2/64
Mapping Table
DNS
Inside Outside
3ffe:3700:1100:1:210:a4ff:fea0:bc97 120.130.26.10
Source = 120.130.26.10
Source = 3ffe:3700:1100:1:210:a4ff:fea0:bc97 Dest = 204.127.202.4
Dest = 3ffe:3700:1100:2::204.127.202.4 NAT-PT
Source = 204.127.202.4
Dest = 120.130.26.10
v4host.4net.org
Source = 3ffe:3700:1100:2::204.127.202.4 204.127.202.4
Dest = 3ffe:3700:1100:1:210:a4ff:fea0:bc97
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QoS in the Mobile – 3G Network
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3GPP Release 5
End-End QoS Framework
T3.207 – End-end QoS architecture:
Complements 23.107 describes Quality of Service for the "GPRS Bearer Service“ (main developments in Rel4)
Introduces a PDF – Policy Decision Function (policy Server) to interwork between applications and IP bearer service (GGSN = Policy Enforcement Point). Also possible mapping between
GPRS and IP bearer services.
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QoS requirements in UE and GGSN
UE GGSN
Capability
DiffServ Edge Function Optional Required
RSVP/IntServ Optional Optional
IP Policy Enforcement Optional Required (*)
Point
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23.107
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UMTS bearer attributes defined for each bearer traffic
class
Conversational Streaming class Interactive class Background class
Traffic class class
Traffic handling X
priority
Allocation/Retention X X X X
priority
Source statistics X X
descriptor
Signalling indication X
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Value ranges for UMTS Bearer Service Attributes
Conversational Streaming class Interactive class Background class
Traffic class class
Maximum bitrate <= 16 000 (2) <= 16 000 (2) <= 16 000 - <= 16 000 -
(kbps) overhead (2) (3) overhead (2) (3)
Delivery order Yes/No Yes/No Yes/No Yes/No
Maximum SDU size <=1 500 or 1 502 (4) <=1 500 or 1 502 (4) <=1 500 or 1 502 (4) <=1 500 or 1 502 (4)
(octets)
SDU format (5) (5)
information
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Mapping from R97/98 GPRS QoS attributes to
Release 99 onwards
Resulting R99 Attribute Derived from R97/98 Attribute
Name Value Value Name
Traffic class Interactive 1, 2, 3 Delay class
Background 4
Traffic handling priority 1 1 Delay class
2 2
3 3
SDU error ratio 10 -6
1, 2 Reliability class
10-4 3
10-3 4, 5
Residual bit error ratio 10-5 1, 2, 3, 4 Reliability class
4*10-3 5
Delivery of erroneous SDUs 'no' 1, 2, 3, 4 Reliability class
'yes' 5
Maximum bitrate [kbps] 8 1 Peak throughput class
16 2
32 3
64 4
128 5
256 6
512 7
1024 8
2048 9
Allocation/Retention priority 1 1 Precedence class
2 2
3 3
Delivery order yes' yes' Reordering Required
SGSN and the GGSN(Information in the
PDP Contexts)
'no' 'no'
Maximum SDU size 1 500 octets (Fixed value)
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IP CoS Basics
Key Functions
Per-flow Rate Traffic
Policing Priority Congestion
Classification
Queuing Avoidance
&
Marking SP
W
R
R
• IP Flow RED
• IP Precedence bits, DSCP Byte
• MPLS CoS bits
100%
• Incoming Physical Interface Stream
• Incoming Logical Interface
• Destination IP address
• Application (stateful) etc…
100% 100%
PLP=1 PLP=0
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Converged Network CoS Design
In a voice / best effort network, three classes (at least) of service are necessary:
• IP network control traffic
• Low bandwidth requirements, not sensitive to latency, jitter
• Must not be starved
• Voice signaling and bearer traffic
• Highest latency and jitter requirements
• Best effort data traffic
• Whatever capacity is left
More complex configurations may or may not be needed in other network
designs (e.g. with VPN service)
More classes = more complexity, no way around this.
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Real World Case Study –
Customer QoS allocations
MPLS Forwarding Behaviour Traffic Type Hardware Drop
EXP Queue Probability
Bits
000 Best Effort IP Traffic Queue 0 -
(UMTS Best Effort Class)
001 Assured Forwarding 12 Queue 2 High
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Real World Case Study –
Customer QoS allocations
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What is Diff-Serv TE ?
Diff-Serv: scheduling/queuing behavior at each node depends on traffic type (indicated by
DSCP/EXP setting ) - hop by hop QoS
MPLS TE: use of constraints to control placement of LSPs. Typically, various traffic
classes share the same LSP. Bandwidth reservations do not take account of the classes of
traffic involved.
MPLS Diff-Serv TE:
• Traffic divided into up to eight Class-Types.
• CSPF and RSVP take the Class-Type into account when computing path of LSP.
• Results in More granular bandwidth reservation.
On each link in network, can have separate bandwidth constraints for each type of traffic
• E.g. limit the bandwidth taken by voice LSPs on a link to a maximum of 40%, data
LSPs take the rest.
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CoS / QoS & Forwarding
Diff-Serv-aware MPLS Traffic Engineering
Guaranteed bandwidth for MPLS
• Combines MPLS DiffServ and DiffServ TE
• Provides strict point to point QoS guarantees
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Components of DS-TE
Three components:
• Per-class admission control – RSVP extensions, IGP
extensions
• Per-class input policing at the edge – LSP Policing
• Per-class scheduling (one queue for all traffic of a given
class) – DiffServ
• Aggregated scheduling: a class queue carries many LSPs
THE RESULT:
• Admission control + policing at the edge + dedicated
queue = guaranteed bandwidth
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Looking into the future
3G Release 6
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3G Release 6 TS 23.221
H.248
RTP
or
UDP/IP or AAL2 AAL2 TDM
Iu cs ATM
Iu b IP
NodeB
PSTN
Iu ps
USIM IP/AAL5
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Service based charging and control
Convergence of service differentiation, service specific policies and charging policies
• IP flow-based charging
• Enable differentiated online and offline charging for the traffic flows belonging to different
services (a.k.a. different service data flows) even if they use the same PDP Context.
• Dynamic policy control enhancements (also ties in with QoS)
• Enable service based local policy control over IP bearer resources to evolve separately from
SIP services.
Requirements:
• Ability to classify IP traffic into services based on content (stateful. Eg- URI)
• Ability to apply flexible charging rules and service based local policy control based on
service classification
• Ability to enforce IP bearer policies for multiple services
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Service based charging and control
Online Charging System*
Gy Gx Gq
Timescale:
• 3GPP Release 6
• Early realization by some vendors at the GGSN
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3G complimentary access technologies
Access technologies that compliment a 3G FDD network by providing high-speed data
services in hot-spot areas
• 802.11 based WLAN, HSDPA, TDD / portable broadband
Requirements:
• Existing core networks to support connectivity to WLAN, TDD access networks
• Allow access to PS services (e.g. IMS) from WLAN access networks
• Ability to handle additional transport capacity as a result of higher bandwidth
Timescale:
• 3GPP Release 6 for basic WLAN inter-working scenarios
• Realization of basic scenarios by many vendors
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3G complimentary access technologies
Intranet / Internet
3GPP Visited Network
3GPP AAA Wf CGw/CCF
Wr/Wb Proxy
WLAN Access Network
Wg
WLAN Wn Wireless Access
Ws/Wc
UE
Gateway
Scenario 3
Wn
3GPP AAA Wx HSS
Server
Wm
D W
'/
Gr
Wo
HLR
'
f
Packet Data
Gateway
OCS CGw/
CCF
Wi
PS Service Network
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Agenda
Mobile overview and the transition to 3G
2.5G data networks
3G - phases of deployment. Focus areas:
• Layer 2/MPLS migration
• IP RAN and transition techniques
• IP Multimedia subsystem and QoS
• ‘Push to Talk’ example
• IPv6
WLAN integration options
Case studies
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High level Scenarios
VPN / Network level integration
Authentication / billing integration
• Web logon: SMS delivered password
• SIM integration
3GPP work – ongoing (GRPS/WCDMA)
Real time handover
• Mobile IP
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VPN / Network Level integration
eg- Leading Asian Wireless Operator
Integration of VPN access for mobile corporate users regardless of access type
Outsource remote access management from corporates, and aggregate users in a layer
3 VPN – common point of subscriber management
Network diagram:
Mobile users mapped
into corporate VPNs
IPSEC / L2TP
(RFC 3193)
MPLS
MPLS Backbone
WiFi User with native
Windows Client
Native
L2TP
M Series (P)
LAC E Series (PE)
GGSN & Tunnel
3G and PHS users Gateway
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Authentication / Billing integration
First approach: web login approach for WLAN
• Username and password login or/
• One time password delivered by SMS/text message
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GPRS/CDMA Example
Telstra Corp. Australia
Mobile centric service, launched in August 2003
Public WLAN access to the Internet and corporate VPNs
Available in hotspot locations throughout Australia
• Target of 600 hotspot locations in 2004
• International roaming through the Wireless Broadband Alliance
Use of centralised control functions (E Series + SDX)
The "Wireless Hotspot" service is expected to become our "workhorse" mobile data
network, especially for corporate users, providing greater bandwidth in high traffic
locations than our cellular GPRS and 1xRTT mobile networks.
- Ted Pretty, Telstra Mobile Group Managing Director
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Mobile Operator focus –
Simple billing for Telstra mobile customers
Time based billing; hourly rate
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How it works - Step One
• User opens up web
browser and tries
to go to Google
• Session directed
to captive portal
software (SDX)
• Choice to enter
mobile phone
number or
username and
password
• Mobile phone
number entered
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Step Two
• One-time password
sent via SMS to
user’s mobile
phone
• Received password
entered into
portal page
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Step Three
• Upon successful
authentication,
captive portal is
released and
original web
destination is
loaded.
• Mini-logout
window to
facilitate signoff.
• Usage billed to
user’s mobile
phone bill once finished
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Authentication on WLAN using
802.1X and EAP on 802.11 - overview
Access Point
RADIUS
Association Ethernet Server
Access blocked
802.11 Associate-Request 802.11 RADIUS
802.11 Associate-Response
EAPOW-Start EAPOW
EAP-Request/Identity
EAP-Response/Identity Radius-Access-Request
EAP-Request Radius-Access-Challenge
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Maintaining subscriber control when using
802.1x/EAP environment
“Transparent RADIUS relay” concept
802.1x access points have Radius client, EAP messages encapsulated in Radius messages
Host MAC address in the calling-station-attribute
Radius relay (BRAS) uses @domain name to forward Radius request to an external EAP capable
Radius proxy or server
BRAS relay stores Host MAC address and awaits authorization data (VR to use, IP pool/address to
use, filters, etc)
DHCP request, based on the host MAC address, creates subscriber interface in proper context
allocates IP address, assign default policies. SDX with no Web login
Access point creates Radius authentication and accounting (stop)
IDAS = Integrated
Policy Control
DHCP Access Server
Bridge
d circu
it
802.1x AP Premium Content
IDAS
Internet
Radius
Relay MPLS VPN
GRE, routed, DSL, FR,ATM, LL, MetroE
802.1x AP
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PWLAN and Mobile
3GPP standards org defined five scenarios for PWLAN integration with 3G
• From common authentication to seamless handover of voice service
• Specified 802.1x based authentication
• Part of 3GPP Release 6, specified in TS 23.234
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Authenticating against the GSM HLR
Existing database with all mobile subscriber information
Existing provisioning and customer care systems are used
EAP/SIM can offer GSM equivalent authentication and encryption
Gateway between RADIUS/IP and MAP/SS7 is required
• Eg Funk Software Steel Belted Radius/SS7 Gateway
• Ulticom Signalware SS7 software
• Sun server E1/T1 interface card
• An overview of the product is in this attachment:
• Major vendors Ericsson, Siemens, Nokia all have or are developing their own offer
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802.1x EAP/SIM authentication from HLR
Transparent RADIUS relay
GW MAP HLR
SS7
EAPoL
RADIUS
RADIUS
Gr Interface
Client -
Authentication
DHCP Discover
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Tight integration proposed by 3GPP
HLR
EAPoL
RADIUS
RADIUS
Gr Interface
Client -
Authentication
Create PDP Context {IP, transparent mode APN,
IMSI/NSAPI, MSISDN, dynamic address requested}
Create PDP Context Response {End User Address}
DHCP Discover
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Real time handover…
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Overview of Mobile IPv4 (RFC2002)
CN
5. 4.
FA HA
Internet
1. and 2. 3.
MN
1. MN discovers Foreign Agent (FA)
2. MN obtains COA (FA - Care Of Address)
3. MN registers with FA which relays registration to HA
4. HA tunnels packets from CN to MN through FA
5. FA forwards packets from MN to CN or reverse tunnels through HA (RFC3024)
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Mobile IP Interworking with UMTS/GPRS
Recommends use of FA Care Of Addresses (CoA), not collocated, to conserve IPv4 addresses
Source:
3GPP
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Registration Process to GGSN FA
IPv4 - Registration UMTS/GPRS + MIP , FA care-of address
4. Create PDP
5. Activate PDP Context Response
Context Accept (no PDP address)
(no PDP address)
6. Agent Advertisement
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Overview of Mobile IPv6
Removes need for external FA in future 3GPP systems
CN
4. 3.
HA
Internet
1. 2.
MN
1. MN obtains IP address using stateless or stateful autoconfiguration
2. MN registers with HA
3. HA tunnels packets from CN to MN
4. MN sends packets directly to CN or via tunnel to HA
• Binding Update from MN to CN removes HA from path.
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3G- Mobile Data Networks
To Summarise…
Interworking different wireless access types is possible in many ways – benefits to the
end users
Short term migration of FR and ATM over MPLS infrastructure can help cut network
and operations costs
Mobile networks are moving to IP both at network transport and
application layer…
• IP UTRAN option – IP out to the base station site
• IP Multimedia subsystem – native IP clients in devices
• Push To Talk is a wildcard; could accelerate IP requirements in the mobile network
before 3G becomes widescale
MPLS, QoS / DiffServ TE, IPv6 and transition techniques are key
requirements in the new mobile carrier network!
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Thank you…!
My contact details:
Email snewstead@juniper.net
Mobile +852 6277 1812
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