DBAS:ADeployableBandwidth
AggregationSystem
KarimHabak†,MoustafaYoussef†,andKhaledA.Harras‡
†Egypt-JapanUniversityofSc.andTech.(E-JUST)
‡CarnegieMellonUniversityinQatar
IFIPNTMS‘12
Motivation
•
Theproliferationofmulti-homed
ormulti-interfaceenableddevices
SocketAPI
Motivation
•
•
Theproliferationofmulti-homed
ormulti-interfaceenableddevices
Theseinterfacesareutilized
oneatatime
SocketAPI
Motivation
•
•
•
Theproliferationofmulti-homed
ormulti-interfaceenableddevices
Theseinterfacesareutilized
oneatatime
Exponentialincrease
inmobiledata
demand
SocketAPI
BandwidthAggregationSystems
• Availabilityofmanysolutionforutilizingthe
availablemultipleinterfaces
• Theavailablesolutionsfaceasteep
deploymentbarrier
– Why??
SolutionsShortcomings
• Requiringupdatingthelegacyapplication
– Ex:Applicationhastoquantifyitsrequirements
• Requiringupdatingthenetworkinfrastructure
andintroducenewcomponents
– Ex:Proxiesandrouters
• Requiringupdatingthelegacyservers
• IntroduceKernellevelmodificationstotheend
nodes
– Requiresrecompilingthekernel
DesignGoals
• Goal1:Avoidmodifyingthelegacyapplications
whilemakinguseoftheircharacteristics
• Goal2:Avoidnetworkinfrastructureupdates
• Goal3:Avoidlegacyserversupdateswhilemaking
useofthisopportunityifavailable
• Goal4:Avoidkernellevelmodificationstothe
clients
• Goal5:Utilizetheavailableinterfacestotheir
maximum
• Goal5:Capturetheuserpreferences
SystemArchitecture
• End-to-End
communication
– Noinfrastructure
updates
SystemArchitecture
• Application
Characteristics
Estimator
– Qualitative
measurements
– Quantitative
measurements
SystemArchitecture
• Modedetection
module
– Aserverlistening
onspecificport
– Specifieseitherthe
serverDBASenabledornot
SystemArchitecture
• Interface
Characteristics
Estimator
– Estimatesthe
available
bandwidthateach
interface
– Usesdestination
basedestimatesin
caseofDBASEnabledservers
SystemArchitecture
• Scheduler
– Schedulesthe
packetsand/orthe
connectionsonthe
differentnetwork
interfaces
SystemArchitecture
• ReceivedData
ReorderingModule
– Usedonlyinpacket
orientedmode
– Reorderthepackets
beforegivingthem
totheapplication
SystemArchitecture
• UserInterface
Module
– Obtainsuser’s
preferencesand
interfaceusage
policies
SchedulingTechniques
• Only-One:
– ReflectsthecurrentOS’sschedulingtechnique
whichselectsonlyoneoftheavailablenetwork
interfaces
• CORoundRobin
– Assignstheconnectionstothedifferentnetwork
interfacesinarotatingbasis
– Doesnottakeintoaccounttheinterfaces
characteristicsandapplicationscharacteristics
SchedulingTechniques
• COWeightedRoundRobin
– Assignstheconnectionstothedifferentnetwork
interfacesinarotatingbasisweightedbythe
interfaceestimatedbandwidthsuchthathigher
bandwidthinterfacesgetassignedmore
connections
– Takestheinterfacescharacteristicsintoaccount
whilenottakingtheapplicationscharacteristics
SchedulingTechniques
• COMaximumThroughput
– Assignstheconnectionstothedifferentnetwork
interfacessuchthatitminimizesthetimeneedto
finishthecurrentsystemloadinadditiontothe
newconnection’sload
– Takesboththeinterfacescharacteristicsandthe
applicationcharacteristicsintoaccount
SchedulingTechniques
• PORoundRobin
– Assignsthepackets/chunkstothedifferentnetwork
interfacesinarotatingbasis
– Doesnottakeintoaccounttheinterfacescharacteristics
andapplicationscharacteristics
• COWeightedRoundRobin
– Assignsthepackets/chunkstothedifferentnetwork
interfacesinarotatingbasisweightedbytheinterface
estimatedbandwidth
– Takestheinterfacescharacteristicsintoaccountwhile
nottakingtheapplicationscharacteristics
Implementation
• DBASMiddleware
– ItisimplementedasaLayeredService
Provider(LSP)
– ItisinstalledasapartoftheTCP/IP
stackinWindowsOS
– Itinterceptssocket-basedconnection
requestsandassignpropernetwork
interfacestothemordistributetheir
dataacrossthedifferentinterfaces
Network
Application
(e.g.Firefox)
Winsock2
API
WS2_32.DLL
SPI
DBAS
Middleware
BaseProtocol
(e.g.TCP/IP)
Implementation
• DBASMonitoringApplication
– Itisusedtocapturestheuserpreferencesand
interfaces’usagepolicies
– ItisalsousedtomonitorDBASmiddlewareandits
estimates
Evaluation
• NetworkTopology
– Clientnodeequippedwithmultiplenetwork
interfaces(IF1andIF2)
– Servernode
– IntermediatenodewithNIST-NETnetwork
emulatorisusedtochangethenetworkinterfaces
characteristics
Evaluation
• ApplicationsModels
– SmallloadapplicationrepresentsInternetbrowsing
• Generateconnectionswithlengthfollowsexponential
distributionwithmean22.38KB
• GenerateconnectionsfollowingaPoissonprocesswithmean
13connection/sec
– LargeloadapplicationrepresentsP2PandFTP
• Generateconnectionswithlengthfollowsexponential
distributionwithmean285KB
• GenerateconnectionsfollowingaPoissonprocesswithmean
1connection/sec
Results(InterfacesHeterogeneity)
Usinginterfacescharacteristicsestimatesachievesupto
396%throughputgains
Results(InterfacesHeterogeneity)
Withoutusinginterfacescharacteristicsschedulingmayachieve
lowerperformancethansingleinterfaceeveninPOscheduling
Results(ApplicationsHeterogeneity)
Usingapplicationscharacteristicsestimatesachievesupto130%
throughputgains
POSchedulingisnotaffectedbyapplicationscharacteristics