ieee globecom futurenet, miami, fl, dec 2010 1 meta-headers: top-down networking architecture with...
Post on 30-Mar-2015
214 Views
Preview:
TRANSCRIPT
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
1
Meta-Headers: Top-Down Networking Architecture with Application-Specific Constraints
Murat YukselUniversity of Nevada, Reno
Reno, NV
yuksem@cse.unr.eduhttp://www.cse.unr.edu/~yuksem
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
2
Motivation: The trends
The variety of applications possible is increasing, especially in wireless wireless peer-to-peer, mobile data, community
wireless The size is increasing:
million-to-billion nodes The dynamism is increasing:
vehicular networks, sensor networks, MANETs
What is unavoidable?: More dynamism, more disruption tolerance, more entities, and more varieties
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
3
Motivation: The big picture
(a) OSI
Transport
Network
Data Link
Physical
Session
Presentation
Application
(b) Wireline
Transport(TCP, UDP)
Network (IP)
Data Link(Ethernet 802.3)
Physical(Fiber, Cable)
Application
(c) Wireless
Transport(TCP, UDP)
Network & MAC (IP, Mobile IP,
802.1x)
Physical(RF, Fiber, Cable)
Application
(d) MANET, peer-to-peer
?
Network & Routing
?
Application
Physical(RF, FSO, Fiber, Cable)
Ap
plicati
on
-Sp
ecifi
c
Hard
ware
-Sp
ecifi
c
Netw
ork
-Sp
ecifi
c
Static Structured Layered invariants
Mobile, ad-hoc, dynamic Unstructured Cross-layer & layered
invariants
We need a systematic way of implementing vertical components to avoid an unhealthy monolithic stack
architecture.
Economics always has the bigger force: economically attractive applications will keep forcing more vertical components into
the stack!
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
4
Motivation: Response to the trends
Wireless research has been responding with 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
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
5
Motivation: Response to the trends
A paradigm shift: wireless resources are becoming massively available 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.
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
6
Why not continue merging layers?
Merging layers: A greedy approach Makes it hard to standardize – bad for sw
engineering
Which layers must be absolutely isolated? 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
7
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! 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 conveyed to the lower layers.
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
8
Meta-Headers: A vertical design tool
A packet meta-header: 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>
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
9
Headers vs. Meta-Headers
Application
Layer 4
Layer 3
Layer 2
Layer 1
message
H4 messageMH1MH2MH3MH4
H3 H4 messageMH1MH2MH3MH4
H3H2H1 H4 messageMH1MH2MH3MH4
H3H2 H4 messageMH1MH2MH3MH4
Traditional packet headers
Application-specific packet meta-headers
Application
Layer 4
Layer 3
Layer 2
Layer 1
Traditional packet headers
Application-specific packet meta-headers
Explicit Meta-Headers
message
messageMH4MH3MH2MH1
MH1 messageH4MH3MH2
H2MH1 H3 messageH4
MH1MH2 messageH4H3
H3H2H1 H4 message
Implicit Meta-Headers
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
10
Meta-Headers: Demultiplexing
H3 H4 messageMH1MH2MH3MH4
Layer 3
Layer 4
Protocol 1 Protocol 2
Dem
ult
iple
xin
g w
ith
tr
ad
itio
nal h
ead
ers
H4 messageMH1MH2MH3MH4
H4 messageMH1MH2MH3MH4
Layer 3
Layer 4
Service 1 Service 2
Dem
ult
iple
xin
g w
ith
m
eta
-head
ers
H3 H4 messageMH1MH2MH3MH4
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
11
Informing Applications about Lower Layer Services
How will upper layers know about the service primitives of the layers lower than the one below?
Reactive – Meta-Headers in Reverse Direction 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 multi-
receiver services may not work
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
12
Informing Applications about Lower Layer Services (cont’d)
Proactive – Pre-informed Designer 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
13
End-to-End Coordination
Application
Layer 4
Layer 3
Layer 2
Layer 1
message
messageMH4MH3MH2MH1
MH1 messageH4MH3MH2
H2MH1 H3 messageH4
MH1MH2 messageH4H3
Traditional packet
headers
Application-specific
packet meta-headers
H3H2H1 H4 message
Application
Layer 4
Layer 3
Layer 2
Layer 1
Layer 3
Layer 2
Layer 1
H2MH1 H3 messageH4
MH1MH2 messageH4H3
H3H2H1 H4 message
Optional feedback loop for conveying available L1-L3 services
1Application at
source prepares meta-headers with default
options and sets flags to probe for available services
2Meta-headers
may or may not get converted to
traditional headers.
3Meta-headers are
filled with available L1-L3 services, and optionally fed back
to the source application.
4Meta-headers are filled
with summary of available end-to-end
L1-L4 services, and fed back to the source
application.
5Application at
source readjusts meta-headers
for joint vertical optimization of
end-to-end performance.
H3H2H1 H4 message
MH1MH2 messageH4MH3
H2MH1 H3 messageH4
MH1MH2 messageH4H3
MH1MH2 messageH4MH3
MH1MH2 messageMH4MH3
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 local optimization of
last hop(s) of the end-to-end
path.
SOURCE
ROUTER
DESTINATION
A dynamic end-to-end negotiation..
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
14
An optimization perspectiveApplication
Top-Down Value Choice Optimization Framework
Application-Specific View of the Network
Application-Specific Constraints
Value Choices
E(application-
basedcost)
Q3(per-layer
state)
B(qualityconstraints)
Meta-header probes questing lower layer services
Meta-headers filled with available services
Q2(per-layer
state)
W2 (implicit)(per-layer constraints)
Network
Network State Information
Network Resource Constraints
Links
Link State Information
Link Resource Constraints
W3 (implicit)(per-layer constraints)
Lagrange multipliers (pieces of E)
Lagrange multipliers (pieces of Q2 and Q3)
Vertical optimizations are possible
More dynamic
Meta-headers as Lagrange multipliers
IEEE GLOBECOM FutureNet, Miami, FL, Dec 2010
15
Summary A top-down networking architecture with meta-
headers 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
16
Thank you!
THE END
This work is supported in part by the U.S. National Science Foundation awards 0721600 and 0721609.
top related