1. 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

2. 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

3. IMM-Milcom’01– 3 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

4. IMM-Milcom’01– 4 Multimedia Protocol Stack Media Transport Application Daemon Kernel Physical Network H.323 SIP RTSP RSVPRTCP RTP TCPUDP IPv4, IPv6, IP Multicast PPPAAL3/4AAL5PPP SONETATM ADDSI V.34 Signaling Quality of Service media encaps (H.261. MPEG) ICMPIGMP SAP 802.11 DNS LDAP MIP-LR MIP variant MMP 188-220 SDP MIPv6 Application DHCP/DRCP Application Layer approach Network Layer HCLOS EPLRS SINCGARS Link

5. IMM-Milcom’01– 5 Related Work and Brief Comparison

6. IMM-Milcom’01– 6 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.

7. IMM-Milcom’01– 7 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

8. IMM-Milcom’01– 8 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

9. IMM-Milcom’01– 9 SIP-Based Mobility in Military Environment Correspondent Host SIP Server LDAP DNS Stream Server SIP Server LDAP DNS Stream Server 1. Register 2. Invite 3. Client moved 5. INVITE Proxy message 7. Re-invite Server Re-direct Server On-going Media Session (RTP) DRCP DNS 192.4.8.18 Mobile Node Pre-session Move MN 192.6.10.18 SIP Domain 1Domain 2 6. Proxy 1B 1A Proxying Registration 4. Invite 192.6.11.20 MN Mid-session Move 192.4.8.20 Server CH moves

10. IMM-Milcom’01– 10 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

11. IMM-Milcom’01– 11 MIP-LR Mobility in Military Environment Correspondent Host (CH) HLR 3 LDAP DNS Stream Server 8. Update CH DHCP/ DRCP j.k.l.m Mobile Node Domain 1Domain 2 HLR 4 LDAP DNS Stream Server 4. Query HLR 1 VLR 1 VLR 2 HLR 2 1. Move 2. Register 7. Move p.q.r.s 5. New address a.b.c.d 6. Data Packets 3. Register

12. IMM-Milcom’01– 12 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)

13. IMM-Milcom’01– 13 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 12 Mobile Node CH X - Cross-over-node 1,2 - MMP Node CH- Correspondent Node

14. IMM-Milcom’01– 14 Integration of Mobility Components gateway Brigade TOC Shorter range ground radio links Brigade TOC Domain 1 Domain 2 CH MH MMP for (Intra-domain Mobility) SIP Server MIP-LR SIP Server MIP-LR SIP server MIP-LR DRCP SIP Server a.b.c.d Inter-domain move IP address changes l.m.n.x SIP, MIP-LR for Inter-domain mobility SIP - Real-time traffic MIP-LR - Non-Real-time traffic Subnet a.b.c.0 l.m.n.0 l.m.p.0 l.m.q.0 Intra-domain move IP address does not change MH

15. IMM-Milcom’01– 15 SIP-MIP transport delay vs. Packet size (Simulation) Total number of hops = 12, N=4, M=4, P=4, p=1 SD - Signaling + Data D - Data

16. IMM-Milcom’01– 16 Experimental Test-bed Results (SIP vs. Mobile IP) 35% Utilization Gain 40% utilization

17. IMM-Milcom’01– 17 Experimental Results (SIP vs. Mobile IP) Latency 16 msec 27 msec

18. IMM-Milcom’01– 18 MMP Comparison with MIP (TCP Throughput) - Simulation

19. IMM-Milcom’01– 19 Experimental Results (MMP vs. Mobile IP) Downlink (100% Throughput increase)

20. IMM-Milcom’01– 20 MIP-LR vs MIP analytical model results

21. IMM-Milcom’01– 21 Experimental Results (MIP-LR vs MIP) MIP-LR vs. MIP Delay 4 6 8 10 12 14 16 18 20 010020030040050060070080090010001100 Bytes per packet Round trip time in Msec MIP MIP-LR 50% reduction in management overhead

22. IMM-Milcom’01– 22 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

23. IMM-Milcom’01– 23 Backup Slides

24. IMM-Milcom’01– 24 SIP Server modes of operation (Proxy & Re-Direct) SIP UA SIP UA

25. IMM-Milcom’01– 25 SIP Mobility Basic Flows Caller A (SIP UA) SIP Re-direct server/registrar Callee B (SIP UA)Callee B (new location) INVITE B REGISTER 180 RINGING 200 OK ACK RTP Media stream Callee moved during call INVITE 302 moved temporarily ACK Re-register Re-INVITE with new Contact address SIP signaling and RTP/UDP session remains intact LDAP Database User application

26. IMM-Milcom’01– 26 SIP Protocol Design Flows CH (SIP UA) SIP server MH (SIP UA) MH (new location) REGISTER RTP Media stream MH moved mid-call INVITE MN Re-INVITE with new Contact (IP)address in SDP SIP signaling and RTP/UDP application remains intact LDAP Database ACN LDAP Database Ground DISCOVER multiple SIP servers LDAP Database Ground LDAP Database ACN DISCOVER multiple SIP servers Moved temporarily Proxy Registration INVITE Configuration & registration Proxy INVITE DOMAIN 1 DOMAIN 2 OK ACK

27. IMM-Milcom’01– 27 SIP Mobility - Basics CH HA FA Home Network MN Tunnelled data data CH SIP Server Home Network MN 1 2 3 4 5 Plain Mobile IP CH SIP Server Home Network MN moves MN Foreign Network SIP Personal Mobility SIP Mid-session mobility 1 2 3 4 1. SIP INVITE 2. 302 client moved 3. SIP INVITE 4. SIP OK 5. Data 1. MN moves 2. MN re-invites 3. SIP OK 4. Data CH SIP Server Home Network MN moves MN Foreign Network SIP Server CH When both move

28. IMM-Milcom’01– 28 MIP-LR Design: Protocol Flow Registration Accept MH HLR 1New VLRHLR 2HLR 3CH Registration (a) (b) (c) (d) (e) (f) (g) Registration Accept Query (FAILED) MH Care of Address Data Packets sent directly GROUND ACN GROUND

29. IMM-Milcom’01– 29 An Abstraction of Basic MMP MMP (micro-mobility) MIP-LR, MIP, etc. (macro-mobility) gateway Internet

30. IMM-Milcom’01– 30 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

31. IMM-Milcom’01– 31 SIP/MIP Throughput Gain Simulation

32. IMM-Milcom’01– 32 Simulation Results (SIP vs. Mobile IP) Latency

33. IMM-Milcom’01– 33 Results from analytical model MIP vs. MIP-LR

34. IMM-Milcom’01– 34 MMP - Registration Call Flow MNIRRIRPG/FAFAuSHACNBS/FLA beacon Roaming detection Cache init Registration Registration Reply Authentication Mobile IP reg. Mobile IP reg. response Authentication response

35. IMM-Milcom’01– 35 MMP - Other Call Flows MNIRRIRPG/FAFAuSHACNBS/FLA Keep-alive route update Registration Reply Mobile IP reg. Mobile IP reg. response Mobile IP Keep-alive Registration Paging Keep-alive paging update Registration