1. I. Matta1 On the Cost of Supporting Mobility and Multihoming Vatche Ishakian, Ibrahim Matta, Joseph Akinwumi Computer Science Boston University

2. I. Matta Mobility = Dynamic Multihoming  Hosts / ASes became increasingly multihomed  Multihoming is a special case of mobility  RINA (Recursive InterNetwork Architecture) is a clean-slate design – http://csr.bu.edu/rina  RINA routing is based on node addresses m Late binding of node address to point-of-attachment  Compare to LISP (early binding) and Mobile-IP  Average-case communication cost analysis  Simulation over Internet-like topologies

3. What’s wrong today? one big, flat, open net Network Transport Data Link Physical Applications Network Transport Data Link Physical Applications Network DL PHY Web, email, ftp, …  There’s no building block  We named and addressed the wrong things (i.e. interfaces)  We exposed addresses to applications www.cs.bu.edu 128.197.15.10 128.197.15.1 128.10.127.25 128.10.0.0 128.197.0.0 TCP, UDP, … IP protocol

4. RINA offers better scoping Network Transport Data Link Physical Applications Network Transport Data Link Physical Applications Network DL PHY TCP, UDP, … IP Web, email, ftp, … IPC Layer  The IPC Layer is the building block and can be composed m An IPC Layer has all what is needed to manage a “private” network, i.e. it integrates routing, transport and management  E2E (end-to-end principle) is not relevant m Each IPC Layer provides (transport) service / QoS over its scope  IPv6 is/was a waste of time! m We can have many layers without too many addresses per layer

5. 5 RINA: Good Addressing – private mgmt  Destination application is identified by “name”  Each IPC Layer is privately managed m It assigns private node addresses to IPC processes m It internally maps app/service name to node address BA I1I1 I2I2 want to send message to “Bob” IPC Layer To: B “Bob”  B Bob IPC Layer

6. 6 RINA: Good Addressing - late binding  Addressing is relative: node address is name for lower IPC Layer, and point-of-attachment (PoA) for higher IPC Layer  Late binding of node name to a PoA address  A machine subscribes to different IPC Layers BA I1I1 I2I2 want to send message to “Bob” BI2BI2 To: B Bob IPC Layer B,, are IPC processes on same machine I1I1 I2I2

7. I. Matta7 RINA: Good Routing  Back to naming-addressing basics [Saltzer ’82] m Service name (location-independent)  node name (location-dependent)  PoA address (path-dependent)  path  We clearly distinguish the last 2 mappings  Route: sequence of node names (addresses)  Late binding: map next-hop’s node name to PoA at lower IPC level sourcedestination

8. 8 Mobility is Inherent  Mobile joins new IPC Layers and leaves old ones  Local movement results in local routing updates CHMH

9. 9 Mobility is Inherent  Mobile joins new IPC Layers and leaves old ones  Local movement results in local routing updates CH

10. 10 Mobility is Inherent  Mobile joins new IPC Layers and leaves old ones  Local movement results in local routing updates CH

11. I. Matta Compare to loc/id split (1)  Basis of solutions to the multihoming issue  Claim: the IP address semantics are overloaded as both location and identifier  LISP (Location ID Separation Protocol) ’06 EID x  EID y EID x -> EID y EID x  EID y RLOC 1x  RLOC 2y Mapping: EID y  RLOC 2y 11

12. Compare to loc/id split (2)  Ingress Border Router maps ID to loc, which is the location of destination Egress BR  Problem: loc is path-dependent, does not name the ultimate destination EID x -> EID y EID x  EID y RLOC 1x RLOC 2y Mapping: EID y  RLOC 2y 12

13. I. Matta LISP vs. RINA vs. …  Total Cost per loc / interface change = Cost of Loc / Routing Update +   [ P cons *DeliveryCost + (1-P cons )*InconsistencyCost ]  : expected packets per loc change P cons: probability of no loc change since last pkt delivery  RINA’s routing modeled over a binary tree of IPC Layers: update at top level involves route propagation over the whole network diameter D; update at leaf involves route propagation over D/2 h, h is tree height 13

14. I. Matta LISP 14

15. I. Matta LISP 15

16. I. Matta RINA 16

17. I. Matta RINA 17

18. I. Matta RINA 18

19. I. Matta MobileIP 19

20. I. Matta LISP vs. RINA vs. … RINA 8x8 Grid Topology RINA uses 5 IPC levels; on average, 3 levels get affected per move LISP 20

21. Simulation: Packet Delivery Ratio  BRITE generated 2- level topology  Average path length 14 hops  Random walk mobility model  Download BRITE from www.cs.bu.edu/brite I. Matta21 RINA LISP

22. Simulation: Packet Delay I. Matta22 LISP RINA

23. I. Matta Bottom Line: RINA is less costly  RINA inherently limits the scope of location update & inconsistency  RINA uses “direct” routing to destination node  More work: prototyping 23

24. I. Matta RINA papers @ http://csr.bu.edu/rina Thank You Questions? http://csr.bu.edu/rina 24