Post on 03-Feb-2022
Internet Connectivity Sharing inInternet Connectivity Sharing inInternet Connectivity Sharing in Internet Connectivity Sharing in MultiMulti--path Spontaneous Networks: path Spontaneous Networks:
C i d I t ti N t kC i d I t ti N t kComparing and Integrating NetworkComparing and Integrating Network--and Applicationand Application--Layer ApproachesLayer Approaches
Paolo BellavistaCarlo GiannelliCarlo Giannelli
1.7.2010 - Mobilware'10DEIS, Università degli Studi di Bologna,
Viale Risorgimento, 2 - 40136 Bologna Italypaolo.bellavista@unibo.it
AgendaAgenda
Spontaneous networkingSpontaneous networkingopportunities and technical challenges
Internet connectivity sharingInternet connectivity sharingmulti-hop, multi-path, heterogeneous, opportunisticopportunisticlayer-3 vs. layer-7 approaches
RAMP middlewareRAMP middlewarelayered architecture
i iddl f iliti f ti dprimary middleware facilities for supporting and facilitating app developmentpreliminary experimental results
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
preliminary experimental results
1/18
SpontaneousSpontaneous NetworkingNetworking (1)(1)gg ( )( )
Impromptu interconnection of mobile and fixed nodesilli t h t t dusers willing to share content and resources
Maximize resource/service utilization by potentially interconnected nodes
heterogeneous wireless technologiesboth infrastructure and ad-hoc connectivitymultiple connectivity opportunities
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
multiple connectivity opportunitiessporadic/opportunistic Internet connectivity
2/18
Spontaneous Networking (2)Spontaneous Networking (2)Node cooperation to
id i l h ti it
UMTS Base Station
IEEE 802.11Access Point
provide single-hop connectivitymanage multi-hop connectivitysupport peer-to-peer services
CDA
E
IEEE 802.11IBSS
BluetoothPi tsupport peer to peer services
FB G
interface providing ad hoc connectivity
Piconet
Bluetooth Piconet
IEEE 802.11IBSS
l h l k
Peer-to-peer resource sharing (Internet connectivity file sharing )
single‐hop link
(Internet connectivity, file sharing, …)service advertising: NodeA provides lesson notesservice discovery: NodeF looks for nodes that share filesservice invocation: NodeF browses and downloads notes stored on NodeA
NodeA and NodeF may reside in different layer 3
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
NodeA and NodeF may reside in different layer-3 networks
3/18
Spontaneous Networking:Spontaneous Networking:Technical ChallengesTechnical ChallengesTechnical ChallengesTechnical Challenges
Heterogeneous nodes and connectivityIEEE 802 11 Bl t th Eth tIEEE 802.11, Bluetooth, Ethernetseveral operating systems
Decentralized and loosely-coupled networkDecentralized and loosely-coupled network management
localized provisioning of layer-2/3 connectivityinterconnection of heterogeneous layer-3 networks
Erratic and unpredictable behaviord b l /d i f knodes abruptly create/destroy pieces of network
nodes dynamically join/move/leave
Scenario and management complexity makes hard the development of novel applications from
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
hard the development of novel applications from scratch => need for middleware solutions
4/18
RAMP: Real AdRAMP: Real Ad--hoc hoc MultiMulti--hop Peerhop Peer--toto--peerpeerMultiMulti hop Peerhop Peer toto peerpeer
Easy-to-use middleware supporting spontaneous network management transparent in relation tonetwork management, transparent in relation to
operating systemswireless technologieslayer-3 network configurationsnode mobility
Unicast and broadcast comm. supportper-packet sendUnicast, sendBroadcast, p p , ,receive
Peer-to-peer service provisioning and discoveryi i i fi d iper-service registerService, findService
RAMP Java prototype available on MS Windows
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
RAMP Java prototype available on MS Windows XP/Vista/7, Linux, and Mac OS X
5/18
RAMP RAMP Layered ArchitectureLayered ArchitectureLayered ArchitectureLayered Architecture
Service Layerhigh-level features for
sendUnicastsendBroadcastreceive
S i
registerServicefindServices
gpeer-to-peer service offering and discoveryDiscovery: mission-oriented E2E Comm
ServiceLayer
localservices
ServiceManager
Discovery
Discovery: mission orientedTTL-bound broadcastServiceManager: registration and advertising
CoreLayer
Dispatcher Listener XHeartbeater
E2E Comm
and advertisingservice invocation via Core Layer
Core LayerCore Layerlow-level primitives for end-to-end communicationE2EComm: communication primitives for data en/decapsulation into RAMP packetsRAMP packetsHeartbeater for local IP addresses gathering and single-hop neighbors discoveryDispatcher: actual inter-node packet forwarding
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
Dispatcher: actual inter-node packet forwardinglistener-based plug-in for run-time packet management
6/18
Internet Connectivity SharingInternet Connectivity Sharingin Spontaneous Networksin Spontaneous Networksin Spontaneous Networksin Spontaneous Networks
Border Nodes (BNs) with di t I t t ti itdirect Internet connectivity share their access UMTS
Base StationIEEE 802.11Access Point
Layer-3 (L3) approachoperating system default
t t t lti hC
DAIEEE 802.11
IBSSgateway to create multi-hop pathsat most one path for each
dF
B
E
G
BluetoothPiconet
nodeLayer-7 (L7) approach
packets managed and interface providing d h ti it
default gateway
Bluetooth Piconet
IEEE 802.11IBSS
L3 multi‐hop path
single‐hop link
packets managed and dispatched by RAMPsimultaneous exploitation of different paths and
ad hoc connectivityL3 multi‐hop path
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
different paths and different access
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Guidelines for InternetGuidelines for InternetConnectivity SharingConnectivity SharingConnectivity SharingConnectivity Sharing
L3 and L7 approaches togetherL3: minimum routing and communication overhead but localL3: minimum routing and communication overhead, but local decisions may affect remote nodesL7: multi-path enabling and operating system transparent, but increased communication overheadincreased communication overheadmultiple modes of combining L3 and L7 approaches
Context aware path selection (see also MMHC)Context-aware path selection (see also MMHC)quantitative metric for dynamic path evaluationlimited information dissemination to minimize overhead
Differentiated metrics at service initialization and provisioning timeprovisioning time
first, coarse-grained evaluation based on rather static context informationthen finer grained dynamic re evaluation based on context
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
then, finer-grained dynamic re-evaluation based on context related to actual run-time performance
8/18
Internet Internet ConnectivityConnectivity SharingSharing::ApplicationApplication ComponentsComponentsApplicationApplication ComponentsComponents
InternetServiceBNs directly connected to the InternetregisterService to advertise Internet connectivity provisioningprovisioning
InternetClientInternetClientRAMP node requiring Internet connectivityfindService to discover BNs providing connectivity
Layer3Managerlayer-3 gateway modification Dispatcher listener monitoring traversing packets on intermediary nodes
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
intermediary nodes
9/18
L3SP Mode:L3SP Mode:LayerLayer--3 Single Path3 Single PathLayerLayer 3 Single Path3 Single Path
BN1 X Y CIEEE 802.11Access Point single hop link1
BNUMTS
Access Point
default gateway
L3multi hop path
single‐hop link
C ll b ti f i t di d
BN2Base StationL3 multi‐hop path
Collaboration of intermediary nodesrequest forwarding from client to BNd i difi ti f l l d f lt tdynamic modification of local default gateway
Layer3ManagerLayer3Managermonitor traversing packets and recognize modification requests
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
qe.g., in Linux route and iptables commands
10/18
L7MP Mode:L7MP Mode:LayerLayer--7 Multi Path7 Multi PathLayerLayer 7 Multi Path7 Multi Path
BN1 X Y CIEEE 802.11Access Point
single‐hop link1
UMTS
Access Pointdefault gateway
L7 multi‐hop path
Data to/from the Internet encapsulated into RAMP
BN2Base Station
ppackets at app layer and forwarded via DispatcherDouble proxy architetcure
I t tCli t/S i t iInternetClient/Service act as proxiese.g., HTTP proxy server on clients and BNs, en/decapsulating HTTP requests and responses
Multi-path connectivityincreased overall bandwidth
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
increased overall bandwidthgreater reliability
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L3L7CMP Mode:L3L7CMP Mode:L3 L7 Combo Multi PathL3 L7 Combo Multi PathL3 L7 Combo Multi PathL3 L7 Combo Multi Path
IEEE 802 11 single hop linkBN1 X Y CIEEE 802.11Access Point
default gateway
L3multi hop path
single‐hop link
BN2UMTS
Base Station
L3 multi‐hop path
L7 multi‐hop path
Both L3 and L7 approachesInternetClient selects the most proper mode atInternetClient selects the most proper mode at runtime
one L3 path + multiple L7 pathsp p pdouble-proxy in case of L7 approachsingle-proxy in case of L3 approach (no InternetService)
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10 12/18
L3SP, L7MP, and L3L7CMP:L3SP, L7MP, and L3L7CMP:a Comparisona Comparisona Comparisona Comparison
L3SP modeprovides direct access to the Internet with no additionalprovides direct access to the Internet with no additional overheadbut path modification requests may affect other nodes
L7MP modeno need of path pre-configurationp p gbut double-proxy en/decapsulation overhead (only HTTP at the moment)
InternetBNX
L3L7CMP modesuitable for dynamic
i t ( L7MP)
Client node
Internet Client
Path L7
Internet Service
L7
L7cation
multi BNY net
environments (as L7MP)reduced overhead(in case of single-proxy)
Selector L3
L3
App
lic path
singlepath
Internet Service
L7
Y
Intern
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
(in case of single-proxy) BNZ
OS
13/18
Dynamic Path SelectionDynamic Path Selection
Context-aware performance monitoring/evaluation and selection of available pathsp
dynamic weight-based exploitation of every BNstatic and dynamic metrics
PathLengthPathLengthstatic comparison of path length
PathThroughputwBN1=0.40wBN2=0.60
wBN1=0.33wBN2=0.67
wBN1=0.67wBN2=0.33at oug put
lightweight throughput monitoring BN1 X Y C
dynamic weight reconfigurationBN2
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10 14/18
L7MP PerformanceL7MP PerformanceGoogle maps browsing: HTTP intensive communicationcommunication
very frequent interactions with limited payload size
B d idth li it ti t d BNBandwidth limitation towards BNsperiodic weights re-evaluation accordingly to really achieved throughputachieved throughputbandwidth allocation swap after 105s Internet
BN
C
BN1
X
125 (25) KB/s
( ) /BN2
25 (125) KB/s
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
Internet
BN1 BN215/18
L3L7CMP L3L7CMP PerfomancePerfomanceSame bandwidth allocation, both L3 and L7 approaches simultaneouslypp y
L3 path towards BN1, L7 path towards BN2throughputs are similar, L3 path slightly betterL7 h i h d b li h l l I t tL7 path weight tend to be slightly lower
Approach swap after 125sweights change accordingly after few iterations
Internet
BN1weights change accordingly after few iterationsC
BN1
X
30 KB/s
30 KB/BN2
30 KB/s
Internet
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
BN1 BN216/18
Conclusions andConclusions andOngoing WorkOngoing WorkOngoing WorkOngoing Work
RAMP supports multi-hop service-oriented communication in heterogeneous spontaneouscommunication in heterogeneous spontaneous networks
easy-to-use API for service development by non-expert programmers
Internet-connectivity sharing as possible central applicationapplication
layer-3 and layer-7 approaches simultaneouslymulti-path for greater quality and reliability
th d i l ti d l tiproper path dynamic evaluation and selection
Ongoing workOngoing worklive multimedia stream via DVB-T re-castingporting to additional mobile platforms, e.g., Google Android
d iPh OS
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
and iPhoneOS
17/18
Any Questions?Any Questions?
Thanks for your attention ☺yQuestions time…
Prototype code and implementation insightshttp://lia.deis.unibo.it/research/RAMP/
Chicago, USA — 1.7.2010 Paolo Bellavista - Mobilware '10
http://lia.deis.unibo.it/Staff/PaoloBellavista/
18/18