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

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 –  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

What’s wrong today? Network Transport Data Link Physical Applications Network Transport Data Link Physical Applications Network DL PHY Web, , ftp, …  We exposed addresses to applications  We named and addressed the wrong things

RINA offers better scoping Network Transport Data Link Physical Applications Network Transport Data Link Physical Applications Network DL PHY TCP, UDP, … IP Web, , ftp, … IPC  E2E (end-to-end principle) is not relevant m Each IPC layer provides service / QoS over its scope  IPv6 is/was a waste of time! m We don’t need too many addresses within an IPC layer

5 RINA: Good Addressing  Destination application is identified by “name”  App name mapped to node name (address)  Node addresses are private within IPC layer m Need a global namespace, but not address space m Destination application process is assigned a port number dynamically BA I1I1 I2I2 want to send message to “Bob” IPC Layer To: B “Bob”  B Bob IPC Layer

6 RINA: Good Addressing  Late binding of node name to a PoA address  PoA address is “name” at the lower IPC level  Node 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

I. Matta 7 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)  Map next-hop’s node name to PoA at lower IPC level sourcedestination

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

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

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

I. Matta Compare to loc/id split (1)  Basis of any solution 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

Compare to loc/id split (2)  Ingress Border Router maps ID to loc, which is the location of destination 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

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

I. Matta LISP

I. Matta LISP

I. Matta RINA

I. Matta RINA

I. Matta RINA

I. Matta MobileIP

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

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

Simulation: Packet Delay I. Matta 22 LISP RINA

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

I. Matta RINA Thank You Questions?