Center (SPICE), Xanthi

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21 Νοε 2013 (πριν από 3 χρόνια και 9 μήνες)

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Workshop at
Space Internetworking
Center (SPICE),
Xanthi


Delay
Tolerant Networking and
Content/Service
-
Centric Networking

Torsten Braun

Universität

Bern

braun@iam.unibe.ch

rvs.unibe.ch



Overview

>
Computer Networks and Distributed Systems @ U Bern


>
Content
-

and Service
-
Centric Networking in

Mobile and Delay
-
Tolerant Networks


>
Conclusions and Outlook

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

2

Research Projects @ Computer Networks
and Distributed Systems

>
Opportunistic Routing for

Highly Mobile Ad
-
hoc Networks

>
Authentication, Authorization,
Accounting, and Auditing in Wireless
Mesh Networks (A4
-
Mesh)

>
Mobile/Wireless

Content
-
Centric
Networks

>
Traffic Adaptivity in

Wireless Sensor Networks

>
Location Based
Analyser


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Torsten Braun: Service
-
Centric Networking

3

A4 Mesh: Environmental Monitoring with
Wireless Mesh Networks

Torsten Braun: Service
-
Centric Networking

Thomas
Staub
, Benjamin
Nyffenegger,
Desislava

Dimitrova
, Torsten
Braun:
Operational
Support of
Wireless Mesh Networks
Deployed for Extending
Network
Connectivity, 1st
International Workshop on
Opportunistic Sensing and
Processing in Mobile
Wireless Sensor and
Cellular networks
(
MobiSense
),
Bilbao,

May 9
-
11
, 2011

Xanthi, September 6, 2011

4

EU FP7 Wisebed (until 6/2011):

WSN Testbed Management System

5

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

TARWIS Experiment Configuration

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

6

Recent WSN Experiments

>
Maximally Traffic
-
Adaptive and Energy
-
Efficient MAC Protocol
[EWSN 2010] and

Software
-
based Energy Usage Estimation [EWSN 2011]

>
Adaptive Forward Error Correction

>
TCP Support


Local data and acknowledgement retransmissions


Adaptive retransmission timeouts based on activity monitoring and
path length detection


Duplicate suppression


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

7

Motivation for Content
-
Centric Networking

>
Today’s network traffic is dominated by information retrieval
rather than point
-
to
-
point communication between machines
or humans.

>
Today: huge amount of data sent redundantly on a link

>
Circuit communication model is not considered as appropriate
any more.

>
Future communication architecture should focus on
information objects instead of nodes.

>
Today, wires and memories solve complimentary issues:


Wires move information in space.


Memories move information in time.

>
Future communications architecture should unify both issues.

[modification of slides on CCN from NDN and
CCNx

projects]

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

8

Traditional Web
Retrieval

/ Web Services

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Torsten Braun: Service
-
Centric Networking

9

web server

/

web service

DNS server

s
earch engine /

s
ervice registry

u
ser’s

end
system

Related Work

>
Peer
-
to
-
Peer Networks


Construction of overlay networks


Content / service discovery,

e.g., using distributed hash tables, flooding, random walks, etc.

>
Web Caching


P
roviding content for local users

>
Content Distribution Networks


Routing and redirection of HTTP requests


Cache management

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

10

Content
-
Centric Networking (CCN)

>
[Jacobson et al., ACM
CONEXT, December
2009]

>
Combination of content lookup and message routing

>
Idea: describe the users’ interests in the message header,

but not where to get it.

>
Messages (using XML encoding)


Interest:
content name, selector


Data:
content name, signature (info), data

>
Hierarchical content names


Example: /unibe.ch/
braun
/lecture/20100405

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

11

Related Projects

>
NDN = Named Data Networking,
www.named
-
data.net


>
CCNx

= Open Source Core Software Project for

Content
-
Centric Networking,
www.ccnx.org

>
Scalable and Adaptive Internet Solutions (SAIL),

www.sail
-
project.eu


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

12

IP Model

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Torsten Braun: Service
-
Centric Networking

13

FIB

FIB:
Forwarding

Information Base

Processing of Interest Message in CCN

1.
Longest prefix match on content name in
Content Store (CS)
:

returning data and discarding Interest

2.
Pending Interest Table (PIT)
match:

adding request to PIT and discarding Interest

3.
Forwarding Information Base (FIB)
match:

forwarding of Interest
towards
data


FIB population
by announcements of content
availability

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

14

CCN Model:
M
atch in Content Store

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

15

FIB

CS: Content Store

FIB:
Forwarding

Information Base

PIT:
Pending

Interest Table

Name

CS

Name

Data

PIT

CCN Model:

Match in

Forwarding Information Base


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

16

FIB

CS

Name

PIT

CS: Content Store

FIB:
Forwarding

Information Base

PIT:
Pending

Interest Table

CCN Model: Match in

Pending Interest Table


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

17

FIB

CS

Name

PIT

x

CS: Content Store

FIB:
Forwarding

Information Base

PIT:
Pending

Interest Table

Content Distribution

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

18

/unibe.ch/
braun
/lecture/20100405


1

3

2

4

5

7

6

Naming

>
Any kind of names are possible → flexible naming

>
Naming approaches

>
2 phases: mapping of
ID to locator,
routing to data source

>
1 phase:
direct ID
-
based routing to
data source

>
Examples


/unibe.ch/
braun
/lecture/20100405


/weather/
greece
/20110906


CCNx

support for simple operations


%C1.org.ccnx.frobnicate~1~37


command in the namespace
org.ccnx


operation is
frobnicate
, which takes 1 and 37 as arguments

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

19

Routing

>
Longest Prefix Match Routing (as in IP)

>
But: different FIB entry semantics


IP: IP address prefix
can be reached
via an outgoing interface for
an existing FIB entry


CCN: content name prefix
might

be reached
via an outgoing
interface for an existing FIB entry

>
FIB entries should be populated proactively for known content.

>
Alternatively, searching for content, e.g., using broadcasting

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

20

Content
-
Centric Networking

>
Advantages


Automatic content distribution


< 1 round
-
trip
-
time


Minimization of latency


Minimization of bandwidth (cf. multicast)


Local congestion control


Built
-
in security

>
Drawbacks


Routing (and naming) as open issue


Lacking support of flexible services

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

21

Service
-
Centric Networking (SCN)

>
CCN is content
-
centric and encodes a few operations on content
as extensions of names.

>
Proposal: Service
-
Centric Networking


E
xtension of content
-
centric networking to support services,
possibly operating on content.


Description of a service using content naming scheme,

e.g., /google.com/file
-
service


Service request to invoke a service in Interest message


Service response in Data message

>
Services


Infrastructure services, e.g., cloud computing services


Client
-
oriented services, e.g., web services, remote procedure calls


Continuous content retrieval and streaming services,

e.g., A/V conferencing, streaming


In
-
network processing, e.g., sensor data aggregation and fusion

22

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

Advantages of SCN

>
Low delay and efficient network resource utilization due to


No need for separate service lookup and service registry


C
aching of service data; extended caching of multimedia data
(transcoding) or sensor data (data fusion)


Optimized service selection

(
considering load, delay metrics for service request routing)


Location
-
based services

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

23

Uniform Naming for Services (Functions)
and Content (Data)

>
Services perform (data) processing and are represented by
functions

to be invoked. Content stores for
data
.

>
Service
-
centric networking should support both data and functions.

>
Object
-
orientated
programming paradigm
integrates
both

functions
and data into objects.

Method calls
among objects
to
invoke
functions.

>
Proposal: Object names for both services (functions) and content
(data), e.g.,


/
youtube.com/rendering


/unibe.ch/
braun
/lecture/20100405

>
Advantages of object
-
oriented approach


Uniform naming


Services can be implemented as a set of cooperating objects


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

24

SCN Object Types

25

content

data

read

1: Content Object

2: Service Object

content

data

read

3: Content/Service Object

function3

function1

function2

function1

function2

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

Example: Audio/Video Mixing

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

26

mix

video

1

read

client

video

2

read

video

3

read

write

write

write

Service request/response

SCN router

Service
-
Centric Network

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

27

Continuous Data Flows

>
CCN Interest messages must be continuously submitted for
continuous data flow, e.g., VoIP, streaming, sensor information

>
Option: deployment of states (cf. gradients in directed Diffusion)
to support continuous forwarding

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

28

Moblity

and DTN Support

Interests

Origin of
Interest

Data

/youtube.com/movies/
crazystupidlove

me

-





⽵/楢攮捨⽢牡畮⽴慬歳⽳灩捥

畳u爱

硸x





Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

29

Encounter

Possible message exchange at encounter

1.
Exchange of interests

2.
Exchange of relevant data

Possibly two phases: own vs. others’ interests


CCN:
Forwarding

of

Data
is

based

on PIT
entries
,
no

usage

in mobile
networks

CCNx in Mobile Environments

>
Benefits:


Broadcast property of the wireless medium


Flexible communication


routes not important


No beaconing required


Reduced average delay / less hops due to
possible caching

>
Problems: challenging evaluation


Repeatability


Unpredictable wireless environments


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

30

Experimentation

Platform

Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

31

Conclusions and Outlook

>
Service
-
Centric Networking as a new paradigm extending
content
-
centric networking using an object
-
oriented naming
concept to be integrated into DTN environments

>
Open Issues


Implementation architectures


Service management and composition


Routing


Service parameter support


Mobile ad
-
hoc networks


Delay
-
tolerant networks




Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

32

Further Reading

>
Torsten Braun, Volker
Hilt
, Markus Hofmann, Ivica
Rimac
,
Moritz Steiner, Matteo
Varvello
:



Service
-
Centric

Networking
,

Fourth

International Workshop on
the

Network
of

the

Future ,
Kyoto, Japan, June

9,
2011

>
Thomas
Staub,
Reto
Gantenbein
,
Torsten
Braun
:
VirtualMesh
:
an
emulation

framework

for

wireless

mesh

and

ad hoc
networks

in
OMNeT
++, SIMULATION
, Vol. 87,
No
.
1
-
2, p.66
-
81,
January
, 2011


>
see

rvs.unibe.ch/
research
/
publications


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

33

Thanks for your attention !

>
rvs.unibe.ch/
research


Xanthi, September 6, 2011

Torsten Braun: Service
-
Centric Networking

34