MANET WG Overview - Internet Engineering Task Force · PDF file• RFC 7188 (OLSRv2/NHDP updates on TLV processing) • RFC 7367 (SMF MIB) ... Select 1-hop Nbr providing only path
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MANETWGOverview96thIETFBerlin2016
ManetWGChairs
WhatisMANET?• MobileAdhocNetwork
– Thevision:tosupportrobustandefficientoperaGoninmobilewirelessnetworksbyincorporaGngIProuGngfuncGonalityintomobilenodes.
– MayoperateinisolaGon,ormayhavegatewaystoandinterfacewithafixednetwork.
• KeyFeaturesofaMANETnetwork– Dynamictopologies– Bandwidth-constrainedwirelesslinks– Energy-constrainedoperaGon– Limitedphysicalsecurity– Wirelessinterfaces
Wiredvs.WirelessOverview
Traditional Network characteristics
Networks are based on high-speed links, with very low transmission error rates
Topology changes are relatively rare, and typically planned events
Strict hierarchical design is easy to enforce
Ad-hoc Network characteristics Low bandwidth, variable
speed links Packet loss rates of 50%
are common Rapid topology changes
makes strict hierarchy impossible
Network must function in harsh environmental conditions
RadioTypes
Radio types • Point-to-Point – These radios typically use
TDMA; some also employ highly directional beams.
• Appear to a router as a single point-to-point link, or a collection of point-to-point links
• Use directional beams for better transmission length, and lower probability of detection/interception
• Broadcast/multicast traffic must be replicated for physical transmission on all radio links
Radio types continued
• Broadcast, Multi-Access radios • At OSI Layer 2, these radios employ MAC
protocols that are similar to Ethernet (e.g. 802.11)
• Base use case is omni-directional, broadcast/multicast transmission is accomplished with a single physical send.
Addressing
Wired Network Topology
10.3.3.x 10.3.2.x 10.3.1.x
Wireless addressing
12.10.80.0 14.22.60.0 22.40.31.0
Subnetting Doesn’t Work!!! (at least not well)
Other Addressing Issues
• Standard methods for auto-assigning non-duplicate addresses in a MANET do not exist
• Reacquiring addresses based on motion or location disrupts applications and causes security issues
IETFMANETDocumentsRFCs
• RFC2501(issuesandconsideraGons)• RFC3561(AODV)• RFC3626(OLSR)• RFC3684(TBRPF)• RFC4728(DSR)• RFC5148(Jiaer)• RFC5444(PacketBuildingBlock)• RFC5497(Gmetlv)• RFC5498(IANAAllocaGons)• RFC6130(NHDP)• RFC6621(SMF)• RFC6622(packetbbintegritycheck)• RFC6779(NHDPMIB)• RFC7181(OLSRv2)• RFC7182(updatedpacketbbintegritycheck)• RFC7183(OLSRv2useofsec)• RFC7184(OLSRv2MIB)• RFC7185(OLSRv2metricraGonal)• RFC7186(NHDPsecthreats)• RFC7187(OLSRv2opGmizaGon)• RFC7188(OLSRv2/NHDPupdatesonTLVprocessing)• RFC7367(SMFMIB)• RFC7466(NHDPopGmizaGon)• RFC7631(TLVnaming)• RFC7722(OLSRv2mulGtopology)• RFC7779(DATmetric)• RFC7859(idenGybasedsignatures)
InthePipe• SecurityThreatsforSimplifiedMulGcastForwarding(SMF)• NHDPMIB• RFC5444Usage• OLSRv2secthreats• OLSRv2mulGpath• DynamicLinkExchangeProtocol• CreditwindowextensionforDLEP
Dead• AODVv2
Neartermdeliverables• ManetManagementanddeployment• DLEPextenGons• MulGcastForwardingInformaGonBase
FirstGeneraGonExperimentalProtocols
MANETBriefHistoryMANETStart~1997-2007• 2ExperimentalProacGveProtocols
• 2ExpReacGve
MANETReboot2005-2016• 1standardProacGve• 1standardReacGve
BuildingBlockApproach2006-2011• Packetformat• Neighbordiscovery• Protocols• GeneralizedmulGcast
Today2010-current• Radio/RouterInterface• MulGcastbuildingblock
approach
Extensions2007-current• Time• Security• ProtocolImprovements
SecThreats(atAD)
SecThreats(InIESG)
SecThreats(RFC7183)
MIB(RFC6779)
MIB(RFC7367)
MANETIANA(RFC5498)
PacketBB(RFC5444)
TimeTLV(RFC5497)
NHDP(RFC6130)
SMF(RFC6121)
MIB(RFC7184)
OLSRv2(RFC7181)
Jiaer(RFC5148)
PacketBBSec(RFC7182)
PacketIBS(RFC7859)
IETFMANETDocumentStructureOverview
IntCheck(RFC7183)
DATmetric(RFC7779)
MulGTopo(RFC7722)
NHDPOpt(RFC7466)
DLEP(WGLCfinished)
PacketBuildingBlock(Packetbb)RFC5444Overview
WhatisPacketbb?RFC5444
• PacketBuildingBlock– apacketformatdesignedforcarryingmulGplerouGngprotocolmessagesforinformaGonexchangebetweenMANETrouters
• KeyFeaturesofPacketbb– MulGplemessagesperpacket– ExtensibleviaTypeLengthValuefields
• PacketTLV• MessageTLV• AddressTLV
– Compression• Addresscompression• TLVcompression
– MulGplexerformulGprotocoloperaGon
Packet
Pkt-headr
Version
Pkt-flags
Pkt-seq-num?
Tlv-block?
Tlvs-length
Tlv*
Tlv-type
Tlv-flags
Tlv-type-ext?
Index-start
Index-stop?
Length
Value?
Message*
Msg-header
Msg-type
Msg-flags
Msg-addr-length
Msg-size
Msg-orig-addr?
Msg-hop-lim
it?
Msg-hop-count?
Msg-seq-num
?
Tlv-block
Tlvs-length
Tlv*
Tlv-type
Tlv-flags
Tlv-type-ext?
Index-start
Index-stop?
Length
Value?
Addr-block*
Num
-addr
Addr-flags
Head-length
Head?
Tail-length
Tail?
Mid*
Prefix-length*
Tlv-block*
Tlvs-length
Tlv*
Tlv-type
Tlv-flags
Tlv-type-ext?
Index-start
Index-stop?
Length
Value?
PacketBuildingBlock(RFC5444)Structure
2/14/2011 18NavalResearchLab
Packet
Pkt-headr
… Tlv-block
… Pkt-Tlv
Tlv-type
…
Value
Message
Msg-header
Msg-type
…
Tlv-block
… Msg-Tlv
Tlv-type
…
Value
Addr-block…
Tlv-block
… Addr-Tlv
Tlv-type
…
ValuePacketBuildingBlock(RFC5444)Usage
2/14/2011 19NavalResearchLab
PacketBuildingBlockRFC5444
,------------------
|PACKET|------------------|*Packetversion:0|*Packetflags:0|,-------------------||MESSAGE||-------------------||*Messagetype:7||*Messageaddr.length:4||*Messageflags:0|`-------------------|`------------------
• SimpleExample
01234567890123456789012345678901+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|00000000|Msgtype=7|00000011|Leng|+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|th=6|TlvBlockLength=0|+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
NeighborhoodDiscoveryProtocol(NHDP)RFC6130Overview
WhatisNeighborhoodDiscoveryProtocol(NHDP/RFC6130)?
• NeighborhoodDiscoveryProtocol– UseslocalexchangeofHELLOmessagessothateachroutercan
determinethepresenceof,andconnecGvityto,its1-hopandsymmetric2-hopneighbors
• KeyFeaturesofNHDP– UsesRFC5444
• Extendable• CanusecommonlydefinedTLVs
– Hellobaseddiscovery• DiscoversoneandtwohopneighborinformaGon• DiscoversSymmetry• Supportsmetrics• DynamicGmers
– ProvidesinformaGonbasesforuseofotherprotocols– MulGpleinterfacesupport
A B C
1 2 3
1 2 3
NHDPExample1StandardSingleInterfaceTopology
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2,4 3
1 2,4 3
NHDPExample2DualAddressedIfaceon1-HopNeighbor
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2 3,4
1 23
4
NHDPExample3DualAddressedIfaceon2-HopNeighbor
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1,5 2,6 3,4
1,5 2,63
4
NHDPExample4DualAddressedInterfaces
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2 3
4
1 2 3
4
NHDPExample5DualInterfaceon2-HopNeighbor
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2
5 4
1 2
5 4
NHDPExample6Dualinterfaceon1-HopNeighbor
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2 3
5 4
1 2
5
3
4
NHDPExample7DualIfaceon1-Hopand2-HopNeighbors
PhysicalNetworkTopology NHDPRepresentaGon
A B C
1 2 3
6 5
1 2
5
3
6
2
5
3
NHDPExample8DualIfaceLocallyandon1-HopNeighbor
PhysicalNetworkTopology
NHDPRepresentaGon
A B C
1 2 3
6 5 4
1 2
5
3
4
6
2
5
3
4
NHDPExample9DualInterfaceonAllRouters
PhysicalNetworkTopology
NHDPRepresentaGon
A B C
1,2 5,6 9,10
3,4 7,8 11,12
1,2 5,6
7,8
9
10
12
11
3,4
5,6
7,8
9
10
12
11
NHDPExample1DualAddressedDualIfacesonAllRouters
PhysicalNetworkTopology
NHDPRepresentaGon
SimplifiedMulGcastForwarding(SMF)RFC6621CDSElecGonOverview
WhatisSMF?• SimplifiedMulGcastForwarding
– providesbasicIPmulGcastforwardingsuitableforMANETuse
• KeyFeatures– DuplicatepacketdetecGon
• IPheaderdupID• Hashbased
– NetworkwidedisseminaGon– ReducedforwardingviaconnecteddominaGngset(CDS)algorithms
– GatewaytotradiGonalInternetIPmulGcast
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
Requirements:• 2-hopneighborinformaGon• UniquerouterpriorityselngsFeatures:• SinglesharedCDSforallrouters• SelfelecGon• SimplesupportforclassicforwardersAlgorithm1. Ifleafnodethen,doNOTforward2. Ifpriority>all1-hopand2-hopneighbors,
forward3. StarGngwithgreatestpriority1-hop
neighborvisitneighbors1. Addneighborsvisitedwith>priority
thanlocaltoqueue2. Popqueue,visititsneighbors
4. Ifany1-hopneighborunvisited,forward
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ECDSRequirements• 2-hopneighborinformaGon• UniquerouterpriorityECDSAlgorithm1. Ifleafnodethen,doNOT
forward2. Ifpriority>all1-hopand2-
hopneighbors,forward3. StarGngwithgreatest
priority1-hopneighborvisititsneighbors1. Addneighbors
visitedwith>prioritythanlocaltoqueue
2. Popqueue,visititsneighbors
1. Ifany1-hopneighborunvisited,forward
UseRouterIDsforthisexampleExamplefrom1Notaleafnode,
nextstep
1isnot>allneighbors,next
step
13isunvisitedso1willforward
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
ResultantCDS
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
Requirements:• 2-hopneighborinformaGon• PrevioushopinformaGonrequired• MethodtoinformneighborsofMPRstatusFeatures:• Sourcespecificfloodingpaths• Electedbyneighbors• ShortesthoppathsusedAlgorithm1. Eachrouterselects,asitsMPRs,asubset
of1-hopneighborswhichcoverall2-hopneighbors
2. RoutersinformneighborsofMRPstatus3. TrafficfirstreceivedfromanMPRselector
isforwardedotherwiseblocked
Examplefrom1
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S-MPRRequirements• 2-hopneighborinformaGon• PrevioushopinformaGon• MethodtoinformNbrsofMPRsS-MPRAlgorithm1. SelectMPRs
1. Select1-hopNbrprovidingonlypathto2-hopNbr
2. Select1-hopNbrwhichwouldcovermostcoverednodes
2. InformneighborsofMPRstatus
3. TrafficfirstreceivedfromanMPRselectorisforwarded
4. Trafficfirstreceivedfromanon-MPRselectisblocked
No2-hopNbrslentocover
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
ResultantMPRelecGon
NoGcethat15doesnotforward
SamplefloodstarGngfrom4
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
ResultantCDS(whenstarGng
from4!)11
15
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
Requirements:• 2-hopneighborinformaGon• MethodtoinformneighborsofMPRstatus• UniquerouterpriorityselngsFeatures:• SinglesharedCDSforallroutersAlgorithm1. MPRelecGonisperformedandsharedin
thesamewayasS-MPR2. Routerswhichhavebeenselectedasan
MPRbyanyotherrouterforwardif1. ithaslargerprioritythanallofits1-
hopneighbors2. the1-hopneighborwiththelargest
priorityhasselecteditasanMPR
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MPR-CDSRequirements• 2-hopneighborinformaGon• MethodtoinformNbrsofMPRs• UniquerouterpriorityselngsMPR-CDSAlgorithm1. MPRelecGonisperformed
andsharedinthesamewayasS-MPR
2. RouterswhichhavebeenselectedasanMPRbyanyotherrouterforwardif1. ithaslargerpriority
thanallofits1-hopneighbors
2. the1-hopneighborwiththelargestpriorityhasselecteditasanMPR
Examplefrom1
Doesnothavelargestpriority15hasselectedusasitsMPR
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SMFCDSalgorithmsillustraGon:• ECDS• S-MPR• MPR-CDS
ResultantCDS 11
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OpGmizedLinkStateRouGngProtocolv2RFC7181Overview
WhatisOLSRv2?• OpGmizedLinkStateRouGngProtocolv2
– AproacGveunicastrouGngprotocolforuseinMANETnetworks.
• KeyFeatures– UsesNHDP
• UsestwohopinformaGon• AugmentsNHDPhellomessageswithOLSRv2specificTLVs
– MetricSupport– UseofmulG-pointrelayfordisseminaGngnetworktopologyusingreducedforwardingset
– Supportsaaachednetworks– Providesshortestpathroutes– DynamicTimers
What’sOpGmizedaboutOLSRv2?• ReducednumberofrouterssourcingTCmessages
– OnlyroutersselectedasMPRsourceTCmessages• ReducedadverGsedaddressincludedintopologycontrol(TC)messages– OnlyMPRselectorsareadverGsed
• ReducGonofforwardedTCmessagesusingMPRelecGon– OnlyMPRneighborsrebroadcastTCmessages.
• Dynamic+distancebasedGmers– allowdynamicallyslowerupdaterates– allowlimitedfloodingofTCmessages(e.g.fisheyeorhazyflooding)
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Reduced#ofSourcesforTCmessages
Reduced#ofAdverGsed
neighborsinTCmessages
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Reduced#ofForwardersforTC
messages
Forwarderswhenwhen
starGngfrom4
ManetDaemon
• GraphState
NHDPInstance
OLSRv2Instance
SMFInstance
NHDPInstance
SMFInstance
NHDPInstance
OLSRv2InstanceOLSRMI
NHDPMI
SMFMI
IF0
IF1
IFN
Mult-cast
Mult-cast
Mult-cast
ManetInterfaceMux(IfN)
ManetInterfaceMux(IF0)
ManetInterfaceMux(IF1)
PacketBBClassMessages
RawPacketBBPackets
SMFChannel
ControlChannel
SMFForw
arding
Engine
SMFController
DynamicLinkExchangeProtocolOverview
WhatisDLEP?
• DynamicLinkExchangeProtocol• KeyFeatures
– AllowsradiostoindicatethecharacterisGcsofvariable-qualityRFlinksastheychange
– Routerscanaskradioforspecificdatarateordelay
• DLEPspecifies“what”dataitemsgetexchanged–NOT“how”thoseitemsareused
What is DLEP (continued) • MANETs need to handle rapid mobility profiles
– Both in terms of topology changes, and devices entering and leaving the network due to mobility
• In these environments, relying solely on ‘HELLO’ and ‘DEAD’ timers running at Layer 3 can be problematic
• And all the while, the link quality (speed, delay) can and does change
• Routers and radios must be able to signal each other in order for route tables to converge quickly – Convergence events are necessary to minimize black-
holes and routing loops – Link metrics are needed to advertize the robustness of
the path
What is DLEP (last slide - I promise)
• DLEP is specified as a 1-hop ONLY protocol – Multicast discovery ‘signals’ are sent/received with
TTL=1 • TCP session employs the Generalized TTL
Security Mechanism (GTSM – RFC 5082) • ALL specified messages are designed to be
exchanged between a radio and its LOCALLY ATTACHED routers – NO Over-The-Air (OTA) messaging is specified – However, some proprietary OTA signaling between
modems and/or modem-to-hub is implicit
DLEP using multiple radios Routers can use radio feedback to monitor link status and find the best wireless paths through complex networks
JTRS Satellite Link
TTNT
CDL
§ Op0mizesIProu0ngoverradionetworks
§ Immediatelyrecognizesandadaptstonetworkchanges
§ Easilyroutesbetweenline-of-sightandnon-line-of-sightlinks
top related