IETF-77-NETEXT Meeting

Fast Handoff using Dormant Bindings in PMIPv6<draft-jeyatharan-netext-pmip-dormant-binding-00>

ByMohana Jeyatharan

&Chan-Wah Ng

IETF-77-NETEXT Meeting

Scenario and Assumptions• Scenario

• MN looses connection via IF1 and makes a handoff to IF2 which can be in idle mode or connected mode

• Assumption on operationAll packets sent to oMAG cannot

reach MN bcos • During sudden disconnection, one

cannot do make before break handoff

• oMAG does not know nMAG address bcos the access types are generally owned by different operators

LMA

nMAG oMAG

Source Access WLAN

Source Access WLAN

MN

Target Access 3G

IF2(prefix P2) IF1(prefix P1)

Vertical handoff from unstable interface to stable interface

IETF-77-NETEXT Meeting

Problem• Problem being tackled

• When disconnection happens, triggering vertical handoff via connected interface will take some time and cause packet loss in downlink. Handoff delay in uplink

• Packet loss will happen in downlink

• Incoming packet loss period::to~t1/t2

• Uplink handoff delay will happen

• Outgoing handoff delay::t3-to

nMAG oMAG LMAMN

3G WiFI

Reg PBU(P1)

Handoff attach

Dereg PBU(P1)

PBA(P1)

RA(P1, P2)

Data

Disconnectionto

t1

t2

t3

IETF-77-NETEXT Meeting

Objective

• Objective of Solution• To set up forwarding state in the system

such that• All downlink packets received at oMAG after

disconnection are immediately sent to the new MAG

• All downlink packets received at LMA after de-registration PBU are immediately sent via target access

• For uplink packets, all packets are sent to LMA via stable connection almost immediately after disconnection

IETF-77-NETEXT Meeting

Solution Features

• A dormant binding is informed to the system in advance with the following rules• When disconnection is notified/detected, send

packets to target access• oMAG sends downlink packets to target access• LMA sends downlink packets to target access• MN sends uplink packets via target access

• When dormant trigger request is received, set up forwarding at network entities a priori so that packet loss can be eliminated when disconnection happens

IETF-77-NETEXT Meeting

Solution Operation

nMAG oMAG LMAMN

3G WiFI

Dereg PBU(P1)

RA(P1, P2)

Data

Dormant binding triggerDBU

DBA

Dormant binding state

createdDormant binding state created

WiFi Disconnection

PBA(P1)Data

Data

Data

Un solicited PBA(P2)

Data

Data

Tunnel setup

IETF-77-NETEXT Meeting

Dormant Binding operation when MAG changes

• Target Access MAG Changes• MN connects to nMAG via

3G and sends PBU [1]

• LMA that has dormant binding state will send unsolicited DBA to unstable/source access MAG [2]

• nMAG address informed

• Unstable/source access MAG will reset tunnel with Target access MAG [3]

LMA

nMAG oMAG

Source Access WLAN

Source Access WLAN

MN

Target Access 3G

IF2(prefix P2) IF1(prefix P1)

[1]PBU [2]Un-DBA(nMAG)[3]Tunnel creation

IETF-77-NETEXT Meeting

Message Structures• Dormant Binding Update [DBU]: PBU with Dormant

Binding Mobility Option carrying stable interface IP address

• Dormant Binding Acknowledgement [DBA]: PBA with Dormant Target Address Mobility Option carrying Target MAG IP address

• Unsolicited PBA: is a normal PBA with a new flag “u” set to 1. Will have HNP mobility option and MN-ID mobility option

• Unsolicited DBA: is a normal PBA with a new flag “u” set to 1. Will have Dormant Target Address mobility option and MN-ID mobility option

IETF-77-NETEXT Meeting

Any Questions?

• Is the work Useful?

• Possibility of considering as a WG item?