Transcript slides - Department of ECE UCF

Meta-Headers: Top-Down
Networking Architecture with
Application-Specific Constraints
Murat Yuksel
University of Nevada, Reno
Reno, NV
[email protected]
http://www.cse.unr.edu/~yuksem
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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Motivation: The trends

The variety of applications possible is
increasing, especially in wireless
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wireless peer-to-peer, mobile data, community
wireless
The size is increasing:
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million-to-billion nodes
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vehicular networks, sensor networks, MANETs
The dynamism is increasing:
What is unavoidable?: More dynamism, more
disruption tolerance, more entities, and more
varieties
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Motivation: The big picture

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Mobile, ad-hoc, dynamic
Unstructured
Cross-layer & layered invariants
Presentation
Application
Application
Transport
Transport
Transport
(TCP, UDP)
(TCP, UDP)
Network
Network
Data Link
Data Link
Session
Physical
(a) OSI
(IP)
(Ethernet 802.3)
Network & MAC
(IP, Mobile IP,
802.1x)
Physical
Physical
(Fiber, Cable)
(RF, Fiber, Cable)
(b) Wireline
(c) Wireless
Application-Specific
Application
Application
?
Network
& Routing
?
Physical
Hardware-Specific

Static
Structured
Layered invariants
Network-Specific

(RF, FSO, Fiber, Cable)
(d) MANET, peer-to-peer
Economics always has the bigger force: economically attractive
applications will keep forcing more vertical components into the stack!
We need a systematic way of implementing vertical components
to avoid an unhealthy monolithic stack architecture.
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Motivation: Response to the trends

Wireless research has been responding with
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optimizing via cross-layer designs
adding custom-designed vertical components to the
stack
Old hat: layered vs. cross-layer tradeoff
Bottom-up cross-layer has been the main
approach

Scarcity of wireless resources dominated the
economics
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Motivation: Response to the trends

A paradigm shift: wireless resources are
becoming massively available

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Community wireless
WiFi hotspots
Google WiFi, AT&T Metro WiFi
Spectrum resources may still be scarce but
connectivity is already ubiquitous
The key metric to optimize is becoming
application utility rather than the wireless
resources
App-specific vertical designs are needed..
We need top-down cross-layer designs in addition to the
traditional bottom-up ones.
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Why not continue merging layers?
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Merging layers:
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Which layers must be absolutely isolated?
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A greedy approach
Makes it hard to standardize – bad for sw engineering
Application, Network, Physical?
Integrating lower level functions with a higher
layer function will prevent them becoming a
substrate for other higher layer protocols

Cellular provisioning in the US – jailbreaks
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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Motivation:
Application Layer Framing (ALF)

Layering was a main component of the e2e architecture..
“a major architectural benefit of such isolation is that it
facilitates the implementation of subsystems whose
scope is restricted to a small subset of the suite’s
layers.”
Clark and Tennenhouse, SIGCOMM’90

But, Integrated Layer Processing (ILP) was there too!


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To achieve better e2e efficiency and resource optimization
ILP never become a reality due to the lack of a systematic way
of doing it.
An ALF-based approach is needed:
network protocol services at lower layers can best be
useful when applications’ characteristics and intents are
to theMiami,
lower
IEEEconveyed
GLOBECOM FutureNet,
FL, layers.
Dec 2010
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Meta-Headers: A vertical design tool
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A packet meta-header:
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vertically travels across the network stack
establishes a vertical communication channel among
the traditional layers
co-exist with the traditional per-layer packet headers
Applications can communicate their intent
across all the protocol layers by attaching the
meta-headers to data.
<meta-headers, message>
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Headers vs. Meta-Headers
Application-specific packet
meta-headers
message
Application
H4 MH4 MH3 MH2 MH1
message
Layer 4
H3 H4 MH4 MH3 MH2 MH1
message
Layer 3
H2 H3 H4 MH4 MH3 MH2 MH1
message
Layer 2
H1 H2 H3 H4 MH4 MH3 MH2 MH1
message
Layer 1
message
Application
MH1 MH2 MH3 MH4
message
Layer 4
MH1 MH2 MH3 H4
message
Layer 3
MH1 MH2 H3
H4
message
Layer 2
MH1 H2
H3
H4
message
Layer 1
H3
H4
message
Explicit Meta-Headers
Traditional packet headers
Application-specific packet
meta-headers
H1
H2
Implicit Meta-Headers
Traditional packet headers
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H4 MH4 MH3 MH2 MH1
Protocol 2
message
Layer 4
Layer 3
H3
H4 MH4 MH3 MH2 MH1
message
H4 MH4 MH3 MH2 MH1
message
Layer 4
Layer 3
H3
H4 MH4 MH3 MH2 MH1
Service 1
message
Demultiplexing with
meta-headers
Protocol 1
Demultiplexing with
traditional headers
Meta-Headers: Demultiplexing
Service 2
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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Informing Applications about Lower
Layer Services

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How will upper layers know about the service
primitives of the layers lower than the one
below?
Reactive – Meta-Headers in Reverse Direction
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detect lower layer services in an on-demand manner
as connections arise
meta-headers rewritten by lower layers in reverse
direction
Requires a closed-loop – connectionless or multireceiver services may not work
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Informing Applications about Lower
Layer Services (cont’d)
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Proactive – Pre-informed Designer
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inform layer k designers about services of layers k-2
and below apriori
too much complexity as the number of lower layer
services increases – rank ordering might help
May not be desirable by ISPs
Regional service discovery via broadcasting –
connectionless
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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End-to-End Coordination
1
Applicationspecific packet
meta-headers
Application at
source prepares
meta-headers with
default options and
sets flags to probe
for available
services
message
Application
MH1 MH2 MH3 MH4
message
Layer 4
MH1 MH2 MH3 H4
message
Layer 3
MH1 MH2 H3 H4
message
Layer 2
MH1 H2 H3
H4
message
Layer 1
H1 H2 H3 H4
message
Traditional
packet headers
SOURCE
2
5
Application at
source readjusts
meta-headers for
joint vertical
optimization of
end-to-end
performance.
4
Feedback loop for
conveying end-to-end
multi-hop L1-L4 services,
possibly as a sequence of
options over multiple hops.
Optional
feedback
loop for
conveying
available
L1-L3
services
Optional feedback
loop for local
optimization of
last hop(s) of the
end-to-end path.
Meta-headers are filled
with summary of
available end-to-end L1L4 services, and fed back
to the source application.
Application
MH1 MH2 MH3 MH4
message
Layer 4
MH1 MH2 MH3 H4
message
Layer 3
MH1 MH2 H3 H4
message
Layer 2
MH1 H2 H3
H4
message
Layer 1
H1 H2 H3 H4
message
DESTINATION
3
Meta-headers may
or may not get
converted to
traditional headers.
Meta-headers are filled
with available L1-L3
services, and
optionally fed back to
the source application.
MH1 MH2 MH3 H4
message
Layer 3
MH1 MH2 H3 H4
message
Layer 2
MH1 H2 H3
H4
message
Layer 1
H1 H2 H3 H4
message
ROUTER
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
A dynamic
end-to-end
negotiation..
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An optimization perspective
Meta-header
probes
questing lower
layer services
Meta-headers
filled with
available
services
Application-Specific Application-Specific
View of the Network Constraints
E
Vertical
optimizations are
possible
B
(application-based
cost)
Lagrange
multipliers
(pieces of Q2
and Q3)
(quality
constraints)
Top-Down Value Choice
Optimization Framework
More dynamic
Meta-headers as
Lagrange
multipliers
Application
Lagrange
multipliers
(pieces of E)
Q3
Q2
(per-layer
state)
W3
(per-layer
state)
Network State
Information
Value
Choices
(implicit)
(per-layer
constraints)
Network Resource
Constraints
W2
(implicit)
(per-layer
constraints)
Network
Link State
Information
Link Resource
Constraints
Links
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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Summary
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A top-down networking architecture with metaheaders
Vertical optimizations at finer temporal and spatial
granularity
A variety of top-down optimizations:
 Top-down routing (layers 5, 3)
 Top-down QoS/value management (layers 5, 3, 2)
 Top-down dynamic transport (layers 4, 3, 2)
A new class of optimization problems aiming to
improve joint performance of multiple layers while
respecting the isolation among them.
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
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THE END
Thank you!
This work is supported in part by the U.S. National Science
Foundation awards 0721600 and 0721609.
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