Authors: A. Dutta, J. Burns, K.D Wong, R. Jain, K. Young Telcordia Technologies

Authors: A. Dutta, J. Burns, K.D Wong, R. Jain, K. Young

Telcordia Technologies

Henning Schulzrinne, Columbia University

Multi-layered Mobility Management for Survivable Network

IMM-Milcom’01– 2

Outline

Motivation Related Work Technology Description

– SIP based Mobility Management

– MIP-LR (Mobile IP with Location Register)

– MMP (Micro Mobility Management)

Integrated Approach Simulation/Experimental Results Conclusions/Future Work


Motivation Propose an Integrated Mobility Management Approach for Survivable

Network that will:– Support Personal mobility independent of user location across domains

using unique URI scheme– Support session and service mobility independent of the network attached– Provide continuous connectivity support for Real-Time (RTP/UDP/IP- e.g.,

audio/video streaming) and Non-Real-time (TCP/IP- e.g., ftp, telnet) application

– Provide intra-domain and inter-domain terminal mobility (pre-session and mid-session)

– Survivability and reliability by replicating server functionality in the nodes in the air and on the ground

– Bound by handoff delay and latency budget for real-time application– Use best features of each mobility management scheme


Multimedia Protocol Stack

Media Transport

App

lica

tion

Dae

mon

Ker

nel

Phy

sica

lN

etw

ork

H.323SIP

RTSP RSVP RTCPRTP

TCP UDP

IPv4, IPv6, IP Multicast

PPP AAL3/4 AAL5 PPP

SONET ATM

ADDSI

V.34

SignalingQuality of Service

media encaps(H.261. MPEG)

ICMP IGMP

SAP

802.11

DNSLDAP

MIP-LR MIP variant

MMP

188-220

SDP

MIPv6

App

lica

tion DHCP/DRCP

Application Layer approach

Network Layer

HCLOS EPLRS SINCGARS

Lin

k


Related Work and Brief Comparison

QUALITATIVE COMPARISON OF DIFFERENT APPROACHESIntra-domainencapsulation

Inter-domainencapsulation

Changesto end-systems

Trianglerouting

Infrastructurechange

Fasthandoff

MIP Yes Yes No Yes No NoMIP-RO Yes Yes Yes No No NoMIP-RR Yes Yes No Yes No YesMIP-FF Yes Yes No Yes Yes Yes

CIP No Yes No Yes Yes YesHAWAII No Yes No Yes Yes YesMIP-LR No No Yes No No YesTeleMIP Yes Yes No Yes Yes Yes

SIP No No No No No Yes


IMM Technology Description

Multi-layer approach to mobility management involves the following components

Application-based component– Session Initiation Protocol (SIP) and Domain Name Service (DNS) servers

interact with Lightweight Directory Access Protocol (LDAP) servers to provide location update and personal mobility while providing continuous connectivity for real-time applications (e.g., streaming audio/video).

Network layer component– Mobile IP with Location Registers (MIP-LR) significantly improves Mobile IP

survivability and performance by allowing replication of the MIP home agent functionality; handles non-real-time application (ftp,telnet, chat).

Local mobility component– Micro-mobility Management Protocol (MMP) inherits cellular systems principle

for mobility management, passive connectivity and handoff control but is designed for IP paradigm. Sets up forwarding caches for each mobile host to handle intra-domain micro-mobility.


Expected Performance Improvement of each mobility component

MMP provides increase in throughput of 100% (goal of ~1000 kb/s throughput compared with baseline of ~500 kb/s throughput at 60 handoffs/min)

Mobile IP provides reduced bandwidth for large degrees of local mobility

MIP-LR provides 50% reduction in management overhead (goal is latency of ~10.5 ms vs. baseline of ~18.5 ms in MIP case for a packet size of 1Kbyte in a small campus environment)

Mobile IP registration adds overhead

Application-layer approach provides 50% latency improvement (reduction from ~27ms to ~16 ms for large packets)

Mobile IP triangular routing increases latency

Application-layer approach provides 35% more bandwidth utilization

Mobile IP requires IP-in-IP encapsulation (20-byte header overhead)

Performance ImproveentState of the Art


SIP Based Mobility Key Features

Mobility as part of application layer signaling – No need to change kernel in the end terminals for RTP/UDP application unlike Mobile IP– Interaction with DNS, HTTP, LDAP for location management– Provides session, service mobility and personal mobility using unique URI scheme

Redundancy/survivability– Determine multiple SIP servers during auto-configuration

Via DRCP configuration option, multicast discovery, use of SRV record in DNS Retransmission during call setup using session timer or switches to secondary server

Hierarchical SIP registration– No need to go back to home registrar, register in the visiting domain - less delay– Registration gets proxied to other SIP servers - Hierarchical registrars - Optimized

Performance– No triangular routing—reduces delay

– No IP-IP tunneling—reduces network load and saves overhead

When both CH and MH move– Use SIP’s Record Route feature to go through SIP server

When SIP server also moves Use Dynamic DNS


SIP-Based Mobility in Military Environment

CorrespondentHost

SIPServer

LDAPDNS

StreamServer

SIPServer

LDAPDNS

StreamServer

1. Register2. Invite

3. Client moved

5. INVITE Proxy message

7. Re-invite

ServerRe-directServer

ServerServer

On-going MediaSession (RTP)

DRCPDNS

192.4.8.18

MobileNode Pre-session

Move

MN

192.6.10.18

SIP

Domain 1 Domain 2

6. Proxy

1B1A

Proxying Registration4. Invite

192.6.11.20MN

Mid-sessionMove

192.4.8.20

Server

CH moves


Mobile IP with Location Registers (MIP-LR) Basic Principles Uses Location Register (LR) databases like commercial cellular

systems– Home Location Register stores location, performs authentication, no

tunneling

– Visitor Location Register performs authentication and registration

Upper protocol layers (TCP, UDP) remain unaware of host mobility

MIP-LR is especially suited to military networks as compared to Mobile IP since it provides– Better performance: less delay and network load on ground

and ACN avoiding triangular routing and IP-IP encapsulation

– Better survivability: allows multiple replicated LRs and LRs placed outside the vulnerable area in ACN


MIP-LR Mobility in Military Environment

CorrespondentHost (CH)

HLR 3

LDAPDNS

StreamServer

8. Update CH

DHCP/DRCP

j.k.l.mMobile Node

Domain 1 Domain 2

HLR 4

LDAPDNS

StreamServer

4. Query

4. Query

HLR 1 VLR 1VLR 2 HLR 2

1. Move

2. Register

7. Movep.q.r.s

5. New address

a.b.c.d

6. Data Packets

3. Register

3. Register3. Register


Micro-Mobility Management Protocol (MMP)

Features (of using MMP for local mobility management)– Forwarding caches for each mobile host to handle intra-domain mobility.– Fast handoffs – reduced data losses at handoffs– Passive connectivity/paging capabilities– Minimal signaling overhead, and no encapsulation overhead makes efficient use of low-

bandwidth links Extended version of MMP improves over other proposed forwarding-cache-based local

mobility schemes such as Cellular IP and HAWAII– Military requirements

Robustness, reliability Network mobility Hierarchical network

– More robust to gateway failure: multiple gateways possible– More robust to node failure: multiple paths to gateway(s) allowed– Optimizes period of gateway beacon messages

Application to military environment– Variations

Large domain version - Large number of MMP nodes under a gateway Small domain version - (e.g., Gateway/MMP node does co-exist in the same host in the smallest domain

version)


MMP - Multiple Paths, Multiple Gateways Illustration

Can be exploited by nodes with multiple layer 2 (radio) links, but does not require all nodes to have multiple layer 2 links– Each node has primary gateway (and optionally a secondary gateway)– For primary gateway, has primary interface (and optionally, a

secondary interface) Concept illustrated below

– Black links: primary path to primary gateway– Blue links: secondary path to primary gateway– Magenta links: path to secondary gateway– Beige links: additional radio links that are none of the above

X X X

Gateway 2Gateway 1

1 2

Mobile Node

CH

X - Cross-over-node1,2 - MMP Node

CH- Correspondent Node


Integration of Mobility Components

gatewaygateway

Brigade TOCBrigade TOC Brigade TOC

Brigade TOC

Shorter range ground radio links

Brigade TOC

Domain 1Domain 2

CH MH

MMP for (Intra-domain Mobility)

SIPServer MIP-LR

SIPServer

MIP-LR

SIP server

MIP-LR

MIP-LR

DRCPSIP

Server

a.b.c.dInter-domain

moveIP address

changes

l.m.n.x

l.m.n.x l.m.n.x

SIP, MIP-LR for Inter-domain mobilitySIP - Real-time traffic

MIP-LR - Non-Real-time traffic

Subneta.b.c.0 l.m.n.0

l.m.p.0l.m.q.0

Intra-domain move IP address does not change

MH MH


SIP-MIP transport delay vs. Packet size (Simulation)

Total number of hops = 12, N=4, M=4, P=4, p=1

SIP/MIP Latency vs. Packet size

0

10

20

30

40

50

60

70

80

90

100

0 300 600 900 1200 1500

Packet Size in bytes

La

ten

cy

in

ms

ec

MIP-SD

SIP-SD

MIP-D

SIP-D

SD - Signaling + DataD - Data


Experimental Test-bed Results (SIP vs. Mobile IP)

SIP vs MIP Utilization Gain

0.2

0.3

0.4

0.5

0 100 200 300 400 500 600 700 800 900 1000 1100

Bytes per packet

SIP

B/W

Gai

n

SIP B/W Gain35% Utilization Gain

40%utilization


Experimental Results (SIP vs. Mobile IP) Latency

SIP vs. MIP Latency

5

10

15

20

25

30

35

40

0 100 200 300 400 500 600 700 800 900 1000 1100

Packet Size in bytes

Late

ncy

in m

sec

SIP

MIP

16 msec

27 msec


MMP Comparison with MIP (TCP Throughput) - Simulation

0

5

10

15

20

25

30

0 0.02 0.04 0.06 0.08 0.1

link latency (s)

kb

yte

/s

base MMP

base MIP

MMP SS


Experimental Results (MMP vs. Mobile IP) Downlink

0

50

100

150

200

0 2 4 6 8 10 12 14

handoffs per minute

TCP

thro

ughp

ut (k

byte

/s)

MMPMIP 0MIP 250MIP 500

(100% Throughput increase)


MIP-LR vs MIP analytical model results

Cost ratio of MIP-LR to MIP, for a = b = f = 2, d = 1, c = r =1

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0 10 20 30 40 50 60 70 80 90 100

Packet-to-Mobility Ratio, p

C

LR

/C

MIP

ld = 1 kB

ld = 100B


Experimental Results (MIP-LR vs MIP)

MIP-LR vs. MIP Delay

4

6

8

10

12

14

16

18

20

0 100 200 300 400 500 600 700 800 900 1000 1100

Bytes per packet

Ro

un

d t

rip

tim

e in

Mse

c

MIP

MIP-LR

50% reduction in management overhead


Conclusions/Future Work Integrated Mobility Management approach takes advantage of

best features of each Mobility Management component Server based component provides survivability, redundancy

and reliability features Each mobility component provides better performance

compared to traditional Mobile IP approach Integrated Mobility Management is being prototyped in the

laboratory test-bed An application layer approach to MIP-LR is being investigated Scalability analysis and deployment scenario in the military

networks are some of the future work


Backup Slides


Location Server

Location Server

SIP /Redirect Server

Client

Client(ibc)

Client

Client

1

2 3 45

67

8 9

1011

INVITE [email protected] id:[email protected]

callee

Abc.com Xyz.edu

[email protected] [email protected]

INVITE lisa@ibc

200 OK

200 OK

ACK [email protected] id: [email protected]

ACK lisa@ibc

200 OK200 OK

1

2

3

4

5

67

8

9



302 moved temporarilyLocation [email protected]

200 OK

ACK [email protected]

200 OK

SIP signaling using proxy server

SIP signaling using redirect server

(caller)

[email protected]

callee

(caller)

[email protected]

SIP/Proxy server

Xyz.edu

Abc.com

SIP Server modes of operation (Proxy & Re-Direct)

SIPUA

SIPUA


SIP Mobility Basic Flows

Caller A (SIP UA) SIP Re-direct server/registrar Callee B (SIP UA) Callee B (new location)

INVITE BREGISTER

180 RINGING

200 OKACK

RTP Media stream Callee movedduring call

INVITE

302 moved temporarily

ACK

Re-register

Re-INVITE with new Contact address

SIP signaling and RTP/UDP session remains intact

LDAPDatabase

Userapplication


SIP Protocol Design Flows

CH (SIP UA) SIP server MH (SIP UA) MH (new location)

REGISTER

RTP Media stream MH movedmid-call

INVITE MN

Re-INVITE with new Contact (IP)address in SDP

SIP signaling and RTP/UDP application remains intact

LDAPDatabase

ACN

LDAPDatabase

Ground

DISCOVERmultiple

SIP servers

LDAPDatabase

Ground

LDAPDatabase

ACN

DISCOVER multiple SIP servers

Moved temporarily

Proxy Registration

INVITE

Configuration & registration

Proxy INVITE

DOMAIN 1 DOMAIN 2

OK

ACK


SIP Mobility - Basics

CH

HA

FA

Home Network

MN

Tunnelled data

data

data

CH

SIPServer

Home Network

MN

1

2

3

4

5

Plain Mobile IP

CH

SIPServer

Home Network

MNmoves MN

Foreign Network

SIP Personal Mobility

SIP Mid-session mobility

1

2

3

4

1. SIP INVITE 2. 302 client moved

3. SIP INVITE4. SIP OK

5. Data

1. MN moves2. MN re-invites

3. SIP OK4. Data

CH

SIPServer

Home Network

MNmoves MN

Foreign Network

SIPServer

CH

When both move


MIP-LR Design: Protocol Flow

Registration Accept

MH HLR 1New VLR HLR 2 HLR 3 CH

Registration

Registration

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Registration Accept

Query

(FAILED)

MH Care of Address

Data Packets sent directly

GROUND ACNGROUND


An Abstraction of Basic MMP

MMP(micro-mobility)

MIP-LR, MIP, etc.(macro-mobility)

gatewaygateway

Internet


Large Domain vs. Small Domain Implementation

What is optimal size of domain?– Too many mobile nodes in a domain may cause scalability problems

– Too few mobile nodes in a domain may not exploit use of micro-mobility scheme

– How many mobile nodes in a brigade, ACN coverage area, and what is the variability in this number? What are mobility rate statistics?

Large domain: gateway at ACN, has following advantages:– Large micro-mobility domain => more efficient mobility management

signaling, fewer inter-domain handoffs

Small domain: gateway on the ground, e.g. in brigade TOC or lower in the hierarchy, has following advantages:– Continues to operate if/when the ACNs leave or fly out of range


SIP/MIP Throughput Gain Simulation

SIP-MIP Throughput GainSimulation

0.2

0.25

0.3

0.35

0.4

0.45

0 200 400 600 800 1000

Packet size in bytes

Th

rou

gh

pu

t G

ain

SIP-MIP Gain


Simulation Results (SIP vs. Mobile IP) Latency

SIP-MIP Latency Simulation

0

5

10

15

20

25

30

35

0 100 200 300 400 500 600 700 800 900 1000

Packet size in bytes

Lat

ency

in m

sec

MIP Latency

SIP Latency


Results from analytical model MIP vs. MIP-LR

Mean delays of MIP and MIP-LRp = 5, t r = 2.5 ms, c = d = f = 1, l c = 100 Bytes

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0 256 512 768 1024 1280

Data packet length (Bytes)

Del

ay (

s)

MIP: a=b=10

MIPLR: a=b=10

MIP: a=b=5

MIPLR: a=b=5


MMP - Registration Call Flow

MN IRR IRP G/FA FAuS HA CNBS/FLA

beaconRoaming

detection

Cache initRegistration

Registration Reply

Authentication

Mobile IP reg.

Mobile IP reg. response

Authentication response


MMP - Other Call Flows

MN IRR IRP G/FA FAuS HA CNBS/FLA

Keep-aliveroute update

Registration Reply

Mobile IP reg.

Mobile IP reg. response

Mobile IPKeep-aliveRegistration

PagingKeep-alive paging update

Registration

Documents

Authors: A. Dutta, J. Burns, K.D Wong, R. Jain, K. Young Telcordia Technologies