On the Cost of Supporting

Transcription

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

2 Mobility = Dynamic Multihoming Hosts / ASes became increasingly multihomed Multihoming is a special case of mobility RINA (Recursive InterNetwork Architecture) is a clean-slate design RINA routing is based on node addresses 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 I. Matta

3 What s wrong today? one big, flat, open net Applications Transport Network Data Link Web, , ftp, TCP, UDP, IP protocol Network DL DL Applications Transport Network Data Link Physical PHY PHY Physical There s no building block We named and addressed the wrong things (i.e. interfaces) We exposed addresses to applications

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

5 RINA: Good Addressing private mgmt want to send message to Bob Bob To: B A Bob B IPC Layer IPC Layer B I 1 I 2 Destination application is identified by name Each IPC Layer is privately managed It assigns private node addresses to IPC processes It internally maps app/service name to node address 5

6 RINA: Good Addressing - late binding want to send message to Bob Bob A IPC Layer B To: B B I 2 IPC Layer I 1 I 2 B, I 1, I 2 are IPC processes on same machine 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 6

7 RINA: Good Routing source destination Back to naming-addressing basics [Saltzer 82] 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 I. Matta 7

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

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

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

11 Compare to loc/id split (1) Basis of solutions to the multihoming issue Claim: Ca the IP address semantics are overloaded oaded as both location and identifier LISP (Location ID Separation Protocol) 06 EID x -> EID y EID x EID y RLOC 1x RLOC 2y EID x EID y Mapping: EID y RLOC 2y I. Matta 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 RLOC 1x RLOC 2y EID x EID y Mapping: EID y RLOC 2y 12

13 LISP vs. RINA vs. Total Cost per loc / interface change = Cost of Loc / Routing Update + ρ [ P cons*deliverycost + (1-P cons) )*InconsistencyCost ] ρ: 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 I. Matta 13

14 LISP I. Matta 14

15 LISP I. Matta 15

16 RINA I. Matta 16

17 RINA I. Matta 17

18 RINA I. Matta 18

19 MobileIP I. Matta 19

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

21 Simulation: Packet Delivery Ratio BRITE generated 2- level topology Average path length 14 hops Random walk mobility model Download BRITE from RINA LISP I. Matta 21

22 Simulation: Packet Delay LISP RINA I. Matta 22

23 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 I. Matta 23

24 RINA papers Thank You Questions? I. Matta 24