1

NoticeContributors grant a free, irrevocable license to 3GPP2 and its Organization Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner’s name any Organizational Partner’s standards publication even though it may include portions of the contribution; and at the Organization Partner’s sole discretion to permit others to reproduce in whole or in part such contributions or the resulting Organizational Partner’s standards publication. Contributors are also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution.This document has been prepared by the contributors to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on the contributors. Contributors specifically reserve the right to amend or modify the material contained herein and nothing herein shall be construed as conferring or offering licenses or rights with respect to any intellectual property of the contributors other than provided in the copyright statement above.

Title: Local BreakoutSource: Rajarshi Gupta/Peerapol Tinnakornsrisuphap/Jun Wang

QUALCOMM Incorporated

Ryuhei Munakata, Tsunehiko Chiba

KDDI

Date: March 31, 2008

Recommendation: Discuss and adopt.

3GPP2 Meeting, March, 2008

2

Background

• CAN rev 0 can already support Local Break out at the AGW through dual IP addresses, for example:– IPv4 and CMIPv4

– IPv4 and IPv6

– IPv6 and CMIPv6

• However two same type of IP addresses are not supported, for example: – Pure IPv4 and Network PMIP IPv4

• This document further enables local breakout to fix the bugs when network PMIP is used– Currently we only have one level LinkID to represent both AGW and LMA/HA

– We propose to introduce level 1 LinkID representing AGW and leave current LinkID to be represent LMA/HA

3

Requirements

• Using PMIP above AGW– Allow local services to be accessible directly from AGW, without going

through LMA– Examples: Inter-technology handoff, Position Location

– Allow breakout-aware applications to use IP interface via AGW– Example: VoIP (SIP via LMA and data via AGW)

– Avoid application-specific configuration in the AGW

• Allow operator to control IP connectivity via the various interfaces

4

Local Breakout Goals

• Allow ATs to communicate with local nodes, at multiple levels

– Under the same local router

– Under the same AGW (having LMA as the first hop router)

• Allow ATs to communicate with nodes on the internet without going through the core network

– For AGW breakout, traffic can bypass home network

• eBS can keep track of accounting of packets

AT

eBS

AGW

Correspondent Node

LMA

Local Services under AGW (Position location,

Inter-technology handoff)

Red = Level 2Blue = Level1, Local breakout at AGW

5

Multiple levels of LinkID

• eBS provides multiple LinkIDs to AT– LinkIDs correspond to the owner entity at

each level– Level1 LinkID identifies AGW

– Level2 LinkID identifies LMA

• At AT– Each LinkID is associated with a different IP

interface

• When an AT is handing off between eBS, new eBS can provide multiple LinkIDs

– If LinkID is the same, AT continues to use the same IP interface

– If different LinkID, AT needs to create new IP interface

• Same concept as in existing UMB

AGW-b

eBS1

LMA/HA-a

eBS2

AGW-c

AT1

LinkID-Level2 identifies LMA/HA-aLinkID-Level1 identifies AGW-b

AT2

LinkID-Level2 identifies LMA/HA-aLinkID-Level1 identifies AGW-c

6

Additional implicit GRE key within same binding

• eBS and AGW need to demultiplex packets for Level 1 and Level 2 – IP address is not adequate since it leads to extra processing overhead

– Also does not support broadcast packets as broadcast packet on forward-link on different interfaces will have the same destination IP address (e.g., broadcast address) so it is not possible to distinguish the target IP interface

• Solution– A single binding is assigned in PMIP

– AGW is assigned only one GRE key (say k)– Where k is an even number

• But, eBS and AGW know implicitly that – GRE key k is mapped to the Level 1 address, while key k+1 is mapped to the Level 2

address of the same user

• eBS and AGW accept packets with both keys

7

Packet demultiplexing at various nodes

• On the RL– AT

– Separates packets for two levels into two LinkIDs

– eBS – Sends Level 1 and 2 packets to AGW within GRE tunnel,

using keys k and k+1

– AGW – Forwards Level 2 packets (GRE key k+1) to LMA

– Forwards Level 1 packets (GRE key k) to local nodes

• On the FL– AGW

– Receives packets from LMA which it sends to eBS with GRE key k+1

– Receives packets from local nodes which it sends to eBS with GRE key k

– eBS– Receives packets in GRE tunnel with keys k and k+1

– Sends to AT on appropriate LinkIDs

– AT– Receives packets for each level on separate LinkIDs

LMA

AGW

eBS

AT

LMA

AGW

eBS

AT

Key

kK

ey k

+1

Key

kK

ey k

+1

GRE tunnel

GRE tunnel

8

Changes to TSG-A/X Spec

• X.S0054 Changes:– X.S0054-100 Addendum:

– eBS and AGW procedures for processing packets with GRE keys k and k+1– Change LinkID format to include Level indication– Allow to send multiple LinkID instances to the SRNC– Clarify pure Simple IP is at level 1 IP interface

– X.S0054-220 Addendum: – Clarify Network PMIP is at level 2 IP interface– DHCP received from Level 2 IP interface should be sent to the LMA/HA for

system configuration

– X.S0054-910 Addendum: – Allow to send multiple LinkID instances to the SRNC

– X.S0054-610: – No need to have DHCP vendor option for IWSF Address discovery from UMB

to HRPD handoff

• A.S0020-0 Addendum Changes:– Level 1 Local Breakout

– eBS and AGW procedures for processing packets with GRE keys k and k+1 – Adding two LinkIDs in DAP Record and IPT-Notification(FLSE) message

9

Conclusions

• Generalized design supporting local breakout at AGW

• Standards based design supports roaming without special configuration

• Minor enhancements to current UMB standards– If no local breakout is used, design reverts to current UMB behavior

• Design extensible to more levels of local breakout