IPv6 in 2G and 3G Networks

John Loughney

North American IPv6 Forum 2004

• Introduction• Relevant IPv6 Status in the IETF• Relevant IPv6 Status in 3GPP• Relevant IPv6 Status in 3GPP2• Conclusion

What IPv6 Brings• Resolves the address space limitation of IPv4• Enables global peer-to-peer services across different networks

• What is possible with IPv4 in limited scale, is globally possible with IPv6

• Less complexity in network maintenance• No private address spaces• No NATs (savings both in equipment and maintenance costs)

• End-to-end security features are easier to deploy with global addresses

IPv6

+44 3 1234567 +44 9 7654321

1080::1:1:2:ABBA:CAFE

END-TO-END PHONE CALL

END-TO-END IP M ULTIM EDIA CONNECTION

1080::AAAA:1:2:3:4

IPv6 Products…Gaining Momentum• Symbian 7.0 supports IPv6.• Microsoft WinXP and Windows server 2003 supports IPv6.• Linux, HP-UX, AIX, VMS, & Solaris 8 shipping IPv6.• Most infrastructure vendors support IPv6

• Nokia shipping IPv6 in IPSO 3.3• Cisco announced IPv6 support from IOS 12.2(1)T.

• Applications• Sendmail, Apache Web server and Squid webcache are IPv6 enabled.• New breed of applications such as 3Degrees are IPv6 only.

• For a current list see: • http://www.ipv6forum.com/navbar/links/v6apps.htm• http://www.ipv6.org/v6-apps.html

Dual Stack Handsets • One common misconception is that IPv6 stack,

especially dual stack, is heavy on terminals.• IPv6 TCP/IP stack size is comparable to IPv4 TCP/IP

stack.• Dual stack (IPv4 and IPv6) size is NOT multiple times the

size of IPV4 stack.• Dual stack (v4/v6) is comparable (only about 15% bigger than)

IPv4 TCP/IP stack.

• Direct correspondence between IPv4 socket library and IPv6 socket library – porting does not require major changes in applications.

Applications Benefiting from IPv6

• Peer-to-peer type of applications.• Push-to-Talk• SIP based multimedia and VoIP• Peer-to-peer games

• IPsec VPNs

IPv6 inIPv6 in

IPv6 in 3GPP Specifications• Support for IPv6 (for user traffic) was fully introduced in

3GPP Release 99.• IPv6 address allocation mechanism was updated in 2002

to allocate a globally unique (/64) prefix (instead of a single address) for every primary PDP context.

• IP Multimedia Subsystem (IMS) - multimedia service infrastructure introduced in Release 5 specifies IPv6 as the only IP version in the IMS to avoid IPv4-IPv6 transition and interworking problems.

Transition to IPv6 in 3GPP networks• 3GPP networks have specific requirements and

scenarios for transition.• Analyzed in the IETF v6ops Working Group

• Transition Scenarios for 3GPP Networks - RFC 3574 • 3GPP Analysis - draft-ietf-v6ops-3gpp-analysis-10.txt

• GPRS transition scenarios:1. Dual Stack UE connecting to IPv4 and IPv6 nodes 2. IPv6 UE connecting to an IPv6 node through an IPv4 network 3. IPv4 UE connecting to an IPv4 node through an IPv6 network 4. IPv6 UE connecting to an IPv4 node5. IPv4 UE connecting to an IPv6 node

• IMS transition scenarios:1. UE connecting to a node in an IPv4 network through IMS 2. Two IPv6 IMS connected via an IPv4 network

PoC and NATs

Client, Private IPv4 address 1PoC Server, PublicIPv4 address 3

Client, PrivateIPv4 address 2

UDP port = 6538

The UDP inactivity timer in NAT can cause the public UDP port 6538 to be assigned to a different mobile, if the mobile does not send any data within a certain amount of time, e.g. in 40 seconds …

NAT

There can be NO NATs betw een the PoC term inal and PoC

Server!

• Even though PoC connections use a PoC server in the network, private addresses cause problems similar to other SIP signaling cases.

• UDP inactivity timers are used with NATs and cause some problems:

The mobile would need to send keep-alive packets to every used public UDP socket in about 30 seconds. This generates unnecessary “overhead” traffic and would be very bad for the battery life.

The mobiles could easily use up all of the operators public IPv4-addresses due to the refreshments, the public UDP ports can’t be assigned to new mobiles.

Thus, for performance reasons, NATs should not be used for PoC !!

Inter-Operator PoC Connectivity with IPv4

Operator 1

Operator 2

Operator 3

Operator 5

Operator 6

Operator 7

Operator 4 Operator 8

Private IPv4

Private IPv4

Private IPv4

Private IPv4

Private IPv4

Private IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

Public Public IPv4

”NAT”

”NAT”

”NAT”

”NAT”

”NAT”

”NAT”

”NAT”

”NAT”

Private IPv4

Private IPv4

• Lots of PoC users require port reservations that can use much of the operator’s public IPv4 address space.

• Current GPRS networks use private addresses almost exclusively.

IMS - IP Multimedia Subsystem

GGSN IMS(IPv6)

Fixednetw ork

W LAN

• IP Multimedia Subsystem (IMS) is an architecture for mobile multimedia services.

• IMS is an application that needs IPv6 to be successful and widely deployed.• For roaming and inter-operator cases.• IMS uses Session Initiation Protocol (SIP)

• IMS enables peer-to-peer applications

IMS with IPv6M ulti-country/operator SIP-connectivity network

Client, Public IPv6 address 1Client, Public IPv6 address 2

PublicIP-routing domain(inter-operatorconnections)

CSCF CSCFSIP Signaling:A’s address = Public IPv6 Address 1

Media from B to A:Sent to Public IPv6 Address 1

• Peer-to-peer connections can be expanded to inter-operator and inter-country whenever the operator wants to do so …

IPv6 basics (for IMS services)

Native IPv6 orIPv6-in-IPv4 tunnels

CSCF

IM S APN IM S APN

HLR

DNS

SGSN

HLR

DNS

SGSN

APNs supporting IPv6 and IPv6 over IPv4 tunneling.

DNS supporting IPv6 APNs & IPv6 address records (AAAA

records)

HLR needs to support provisioning ofPDP-contexts with type = IPv6

IPv6 capable Firewalls

GGSN GGSN

IPv6 capable servers (e.g. IMS)

Support for IPv6 PDP context signaling in SGSN. IPv6 capable terminals

CPS site routerwith IPv6 over IPv4

tunneling(may not be needed)

Turning IPv6 onis quite simple• GGSN & SGSN supporting IPv6

• HLR, DNS and Firewallsw update

• HLR, DNS and GGSN configurations

• IPv6 server site has an IPv6-capable router

• IPv6-capable terminals

IPv6 inIPv6 in

IPv6 in 3GPP2• 3GPP2 IS-835C specifies Simple IPv6

• /64 addresses through PPP.• no duplicate address detection.

• Mobile IP• MIPv6 is now RFC 3775!• 3GPP2 will incorporate this now that MIPv6 has after RFC status in

the IETF.• 3GPP2 standardization plan for MIPv6 is to be part of IS-835 Rel D

(to be published mid-2004)• 3GPP2 may also need some context transfers between PDSN’s

when MIPv6 is deployed.

• 3GPP2 and 3GPP are Co-operating on IMS• 3GPP2 IMS supports both IPv4 and IPv6

Transition Scenarios for 3GPP2 Operators

• Many possible scenarios for network transition.• Simple IPv4 -> Simple IPv6• Mobile IPv4 -> Simple IPv6• Mobile IPv4 -> Mobile IPv6

• Various choices for upgrading network• Upgrade mobile terminals and PDSNs and some services to dual-

stack. Leave operator core network as IPv4.• Upgrade only mobile terminals and some services to dual-stack.

Employ transition mechanism on mobile.

IPv4 and IPv6 Network

PDSNPDSN OperatorNetwork

OperatorNetwork

EDGEEDGEROUTERROUTER IPv6

InternetIPv6Internet

IPv4Internet

IPv4InternetOperator

IPv4 Services

IPv4 Host

IPv6 HostIPv4/IPv6 Host

IPv4/IPv6 Host

ROUTER2ROUTER2

ROUTER1ROUTER1

Operator Network

DST

IPv4/IPv6 Host

Operator IPv6 Services

Dual-Stack• Mobile Perspective

• Mobile can open an IPv4 only, IPv6 only or both IPv4 and IPv6 connection with the PDSN.

• Mobile can add or remove IP or IPv6 NCPs at any time.• Mobile will use DNS to determine the address family of the end-host.• Mobile will decide to use either IPv4 or IPv6 based on the address

family of the end-host.

• Network Perspective• PDSN and Edge router must be upgraded to dual-stack.• PDSN can tunnel IPv6 packets over IPv4 if the operator core

network is IPv4 only.• PDSN IPv4 -> dual-stack upgrades are usually software upgrades.

IPv4/IPv6 Host

Dual Stack Access

PDSNPDSN OperatorNetwork

OperatorNetwork

EDGEEDGEROUTERROUTER IPv6

InternetIPv6Internet

IPv4Internet

IPv4InternetOperator

IPv4 Services

IPv4 Host

IPv6 HostIPv4/IPv6 Host

IPv4/IPv6 Host

ROUTER2ROUTER2

ROUTER1ROUTER1

Operator Network

DST

Operator IPv6 Services

IPv6 packets

IPv6 tunneled over IPv4

IPv6 packets

IPv4 packets

Advantages of Dual-Stack

• Does not require tunneling on the wireless link.• Pricing issues on wireless usage.• Bandwidth and latency issues on the wireless link

• Services can be upgraded to IPv6 in a phased manner.• Use of DNS records (AAAA or A records) is the central

control point for transitioning services.• Software upgrades required for network entities, for the most

part.

Summary• IPv6 resolves IPv4 address space limitations and

enables peer-to-peer connectivity in global scale• Co-existence of IPv4 and IPv6.

1.Enable IPv6 in end nodes and networks2.Make applications use IPv6.

• Enabling IPv6 in mobile network is relatively straight-forward.• IMS era is here

• Commercial IMS network elements & IMS services (file sharing, peer-to-peer gaming, ...) piloting in 2004

• Wide-scale, commercial IMS deployment in from 2005 onwards• IPv6 is an important enabler for IMS

However, IPv6 can be used for more than just IMS.

• Connecting People