1. 1 © 2001, Cisco Systems, Inc. Updated_03-09-01 Mobile IP Lessons Learned The early years

2. 2 © 2001, Cisco Systems, Inc. Updated_03-09-01 Who needs Mobile IP anyway? 2Updated_01-02-01 © 2001, Cisco Systems, Inc.

3. 3 Updated_03-09-01 © 2001, Cisco Systems, Inc. A Word from the Nay Sayers Nomads dont have any problems today Dynamic addressing works just fine We dont have enough v4 addresses as it is

4. 4 Updated_03-09-01 © 2001, Cisco Systems, Inc. Cellular Mobility User can handover mid flow Simplifies layer 2 macro mobility Easier to manage than dynamic address pools Important part of 3G standards Cleaner user experience

5. 5 Updated_03-09-01 © 2001, Cisco Systems, Inc. Multiple Media Networks Cost based network selection Go between 802.11, cellular, satellite, etc Supported in Ciscos IOS Mobile Network

6. 6 Updated_03-09-01 © 2001, Cisco Systems, Inc. Clients Host device ProsCons Terminal Based Laptops, PDAs, etc More features Hard to deploy and manage Embedded Proxy Handset, Network Access pt. Transparent to attached clients, Easier to manage Tied to media, fewer features, less security Mobile Router Router Clients not mobile, Central Management Harder to provision and deploy

7. 7 © 2001, Cisco Systems, Inc. Updated_03-09-01 Infrastructure What you really need to know to keep your job. 7Updated_01-02-01 © 2001, Cisco Systems, Inc.

8. 8 Updated_03-09-01 © 2001, Cisco Systems, Inc. SAM, An Engineers Best Friend Scalability – Bigger is better Availability – Uptime is king Manageability –Knowledge is power

9. 9 Updated_03-09-01 © 2001, Cisco Systems, Inc. Scalability Maximum number of users per box Number of users per rack Max Users Throughput, registration rate & memory

10. 10 Updated_03-09-01 © 2001, Cisco Systems, Inc. Did you know… …there is a significantly higher proportion of signaling traffic to user traffic required for mobility management than traditional dynamic IP routing Thats why we use Mobile IP. Traditional routing protocols would not scale with the quantity and frequency of mobility updates

11. 11 Updated_03-09-01 © 2001, Cisco Systems, Inc. Registration Rates Even with large foreign agent provinces each user may reregister every 1-2 hours 1 million users reregistering every 2 hours is ~140 registrations per second. With 200k users per HA thats 28 registrations per second Province – The geographic area covered by a single foreign agent interface

12. 12 Updated_03-09-01 © 2001, Cisco Systems, Inc. AAA requirements Every registration requires a Security Association lookup SAs can be stored locally or in a AAA server How do you handle 140 queries per second per million users?

13. 13 Updated_03-09-01 © 2001, Cisco Systems, Inc. AAA Deployment strategies ProsCons Centralized Easy to manage and provision Hard to scale, Latency can be a problem Distributed No WAN concerns or latency problems Hard to plan, manage, deploy and provision Central + Cache Best of both worlds Cache Management Problems

14. 14 Updated_03-09-01 © 2001, Cisco Systems, Inc. Tunnel requirements 1 tunnel per Foreign Agent 1 tunnel per co-located care of address Tunnels can limit scalability

15. 15 Updated_03-09-01 © 2001, Cisco Systems, Inc. Availability Uptime is king 100% SYSTEM uptime is the goal Remember, system uptime is not box uptime

16. 16 Updated_03-09-01 © 2001, Cisco Systems, Inc. HA Availability MN does not learn about HA failure until re-registration Bindings are stateful HA usually hosts a large number of subscribers

17. 17 Updated_03-09-01 © 2001, Cisco Systems, Inc. Ciscos HA Redundancy Built on HSRP Replicates bindings in near real time Transparent to Mobile Node Bindings AND cached Security Associations are replicated

18. 18 Updated_03-09-01 © 2001, Cisco Systems, Inc. Manageability Fast response to outages Capacity Planning Performance management

19. 19 Updated_03-09-01 © 2001, Cisco Systems, Inc. RFC 2006 MIB Good fault management support Total and per user counters for registrations and errors Poor capacity/performance management support Must iterate through the binding table to count bindings Cisco MIB supports enhanced features

20. 20 Updated_03-09-01 © 2001, Cisco Systems, Inc. Extracting Performance data HA Registration throughput and performance haRegistrationAccepted & haRegRepliesSent vs time faRegRepliesRelayed & haRegRepliesSent vs time FA Registration throughput and performance faRegRequestsReceived & faRegRequestsRelayed vs time faRegRepliesRelayed & faRegRepliesRelayed vs time

21. 21 Updated_03-09-01 © 2001, Cisco Systems, Inc. Internet Deployment Updated_01-02-01 © 2001, Cisco Systems, Inc.

22. 22 Updated_03-09-01 © 2001, Cisco Systems, Inc. Realities of MIP Deployment The Internet was designed to support Broadband and Dial-up Security concerns force tight network implementation Mobility doesnt fit naturally

23. 23 Updated_03-09-01 © 2001, Cisco Systems, Inc. Ingress filtering A classic problem in MIP Network designers block incoming traffic with an internal source address Unicast RPF is probably a more dangerous problem Reverse Tunnels offer a solution HA Internet 10.1.2.0 10.1.2.45

24. 24 Updated_03-09-01 © 2001, Cisco Systems, Inc. Ingress filtering A classic problem in MIP Network designers block incoming traffic with an internal source address Unicast RPF is probably a more dangerous problem Reverse Tunnels offer a solution HA Internet 10.1.2.0 10.1.2.45

25. 25 Updated_03-09-01 © 2001, Cisco Systems, Inc. Path MTU Discovery Many network designers block all inbound ICMP Triangle routing causes problems not normally seen TCP Session opens, but hangs Windows support black hole detection

26. 26 Updated_03-09-01 © 2001, Cisco Systems, Inc. WAP MTU length problems WAP relies on IP fragmentation Fragmentation occurs at WAP gateway servers MTU Fragments cant be fragmented Gateway MTU must be <= path MTU including tunnel

27. 27 Updated_03-09-01 © 2001, Cisco Systems, Inc. Private Addressing Good for Walled Gardens Large Scale NAT can be difficult No support for overlapping addresses in the FA

28. 28 © 2001, Cisco Systems, Inc. Updated_03-09-01 It is worth it! Updated_01-02-01 © 2001, Cisco Systems, Inc.

29. 29 Updated_03-09-01 © 2001, Cisco Systems, Inc. Dont Worry A Mobile IP network is just as easy to build as any IP network. There are just a few new rules.

30. 30 Updated_03-09-01 © 2001, Cisco Systems, Inc. Sweet Rewards Seamless IP connectivity Transparent user experience Limitless Possibilities

31. 31 Updated_03-09-01 © 2001, Cisco Systems, Inc. Are you Ready? There are plenty of challenging problems ahead, but the reward is great.

32. 32 Updated_03-09-01 © 2001, Cisco Systems, Inc. Fire Away? Questions?