Transcript 3rd Edition: Chapter 1 - Tokyo Metropolitan University

On the Cost of Supporting
Mobility and Multihoming
Vatche Ishakian, Ibrahim Matta, Joseph Akinwumi
Computer Science
Boston University
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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

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
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What’s wrong today?
one big, flat, open net
Applications
Transport
Web, email, ftp, …
TCP, UDP, …
Network
Applications
IP protocol
Transport
Network
Network
Data Link
DL
DL
Data Link
Physical
PHY
PHY
Physical
128.10.0.0
128.197.0.0
www.cs.bu.edu
128.197.15.10
 There’s no building block
 We named and addressed the wrong things (i.e. interfaces)
 We exposed addresses to applications
RINA offers better scoping
Applications
Web, email, ftp, …
Transport
TCP, UDP, …
Network
IP
Data Link
Physical
IPC Layer
Applications
IPC Layer
Transport
Network
Network
DL
PHY
DL
PHY
Data Link
IPC Layer
Physical
 The IPC Layer is the building block and can be composed

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

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
RINA: Good Addressing – private mgmt
Bob
want to send message to “Bob”
A
“Bob”B
B
IPC Layer
I1
To: B
I2
IPC Layer
 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
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RINA: Good Addressing - late binding
Bob
want to send message to “Bob”
A
B
IPC Layer
To: B
I1
BI2
IPC Layer
I2
B, I1 , I2 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
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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
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Mobility is Inherent
MH CH
 Mobile joins new IPC Layers and leaves old ones
 Local movement results in local routing updates
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Mobility is Inherent
CH
 Mobile joins new IPC Layers and leaves old ones
 Local movement results in local routing updates
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Mobility is Inherent
CH
 Mobile joins new IPC Layers and leaves old ones
 Local movement results in local routing updates
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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
EIDx  EIDy
EIDx -> EIDy
RLOC1x  RLOC2y
EIDx  EIDy
Mapping: EIDy  RLOC2y
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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
EIDx -> EIDy
RLOC1x RLOC2y
EIDx  EIDy
Mapping: EIDy  RLOC2y
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LISP vs. RINA vs. …
 Total Cost per loc / interface change =
Cost of Loc / Routing Update +
r [ Pcons*DeliveryCost + (1-Pcons)*InconsistencyCost ]
r:
expected packets per loc change
Pcons: 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/2h, h is tree height
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LISP
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LISP
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RINA
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RINA
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RINA
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MobileIP
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LISP vs. RINA vs. …
8x8 Grid Topology
RINA uses 5 IPC levels; on average, 3 levels get affected per move
LISP
RINA
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Simulation: Packet Delivery Ratio
 BRITE
generated 2level topology
 Average path
length 14 hops
 Random walk
mobility model
 Download
BRITE from
RINA
LISP
www.cs.bu.edu/brite
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Simulation: Packet Delay
LISP
RINA
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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
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RINA papers @
http://csr.bu.edu/rina
Thank You
Questions?
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