Post on 11-Jan-2016
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On the Cost of Supporting Mobility and Multihoming
Vatche Ishakian, Ibrahim Matta, Joseph AkinwumiComputer ScienceBoston 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
What’s wrong today?one big, flat, open net
Network
Transport
Data Link
Physical
Applications
Network
Transport
Data Link
Physical
Applications
Network
DL DL
PHY 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.edu128.197.15.10
128.197.15.
1
128.
10.1
27.2
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128.10.0.0 128.197.0.0
TCP, UDP, … IP protocol
RINA offers better scoping
Network
Transport
Data Link
Physical
Applications
Network
Transport
Data Link
Physical
Applications
Network
DL DL
PHY PHY
TCP, UDP, …
IP
Web, email, ftp, …
IPC Layer
IPC Layer IPC Layer
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
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RINA: Good Addressing – private mgmt
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
BA
I1I2
want to send message to “Bob”
IPC Layer
To: B
“Bob”B
Bob
IPC Layer
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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
I1 I2
want to send message to “Bob”
BI2
To: B
Bob
IPC Layer
IPC Layer
B, , areIPC processeson same machine
I1 I2
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RINA: Good Routing
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
source destination
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Mobility is Inherent
Mobile joins new IPC Layers and leaves old ones Local movement results in local routing updates
CHMH
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Mobility is Inherent
Mobile joins new IPC Layers and leaves old ones Local movement results in local routing updates
CH
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Mobility is Inherent
Mobile joins new IPC Layers and leaves old ones Local movement results in local routing updates
CH
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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
EIDx EIDy
RLOC1x RLOC2y
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
EIDx EIDy
RLOC1x RLOC2y
Mapping: EIDy RLOC2y
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LISP vs. RINA vs. … Total Cost per loc / interface change =
Cost of Loc / Routing Update +
[ Pcons*DeliveryCost + (1-Pcons)*InconsistencyCost ]
: 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. …
RINA
8x8 Grid TopologyRINA uses 5 IPC levels; on average, 3 levels get affected per move
LISP
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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
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RINA
LISP
Simulation: Packet Delay
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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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