2009 03 11 routing oslo - universitetet i oslo · `routing basics `quality of service routing...

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11/03/2009 Oslo NO Oslo, NO Marília Curado [email protected] ` Routing Basics ` Quality of Service Routing ` Routing in Wireless Mesh Networks ` Research Challenges ` Projects 4

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  • 11/03/2009Oslo NOOslo, NO

    Marília [email protected]

    Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    4

  • Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    5

    RIPOSPFBGP

    6

    GoalsE d t d ti it◦ End-to-end connectivity

    ◦ Maximise network performance◦ Fault tolerance

    Ad t ti t d i t l i◦ Adaptation to dynamic topologies

    Building blocksg◦ Routing policies◦ Routing information exchange◦ Path computationp◦ Routing table maintenance

    ◦ Forwardingg

    7

    IG IG

    IG

    IGIG

    IG IG

    IGIG

    EG

    CoreNetwork

    EGEG Sistema autónomo

    Sistema autónomo

    EG

    IG IG IG IG

    Sistema autónomo

    IG

    G GIG - Interior GatewayEG - Exterior Gateway

    8

  • Protocol◦ Exchange of routing information

    AlgorithmAlgorithm◦ (Shortest) Path computation

    V2 V35

    8

    3 6

    3

    5

    V1V6

    2

    3

    17

    2 2 33

    11

    24

    8

    V4 V5

    71

    1

    2

    9

    Distance Vector◦ Each router sends to its neighbors information

    about the distance to all the destinations it knows

    Link State◦ Each router sends/floods information about the

    state of its links

    10

    Routing Information Protocol (RIP)

    Open Shortest Path First (OSPF)

    Border Gateway Protocol (BGP)

    11

    Routing Information Protocol (RIP)Interior Gateway Routing Protocol (IGRP)Interior Gateway Routing Protocol (IGRP)

    ◦ Each router sends to its neighbors information about the distance to all the destinations it knows

    ◦ Based on the information received from its neigbors, each router computes the shortest path to all destinations

    ◦ Routing metricNumber of hops

    ◦ AlgorithmBellman-Ford

    The routers are not aware of the topology of the network – only the distance to the destinations

    12

  • 13

    Open Shortest Path First (OSPF)

    Each router floods information about the state of its links Every router has a complete map of the network topologyEvery router has a complete map of the network topology

    ◦ Routing metricN b f hNumber of hopsValue configured

    l h◦ AlgorithmDijkstra

    14

    15

    Fast convergence without loops◦ Flooding◦ Flooding◦ Coherent maps of the network in all nodes

    Support for multiple metricsSupport for multiple metrics◦ One network map for each metric

    Support for multiple pathsSupport for multiple paths◦ Load balancing◦ QoS aware routing

    Scalability◦ Hierarachical routing

    16

  • Sistema autónomo

    ASBRÁrea A Área B

    Área C

    ABR ABR

    ASBR

    17

    Category Information Maintained Communication Partners

    Information Distributed

    Distance vector

    Distance vectors for all destinations

    Neighbour nodes Distance vectors for all destinations

    Network weighted graph All nodes in the State of theLink state

    Network weighted graph All nodes in the network

    State of the individual links of each node

    18

    Path Vector Protocols

    ◦ Border Gateway Protocol (BGP)

    ◦ Inter-Domain Routing Protocol (IDRP)

    Why not Link State or Distance Vector?

    19

    Distance-vector◦ Assumes all routers use the same routing metric◦ Policy information is not distributed

    Link-state◦ Metrics may vary in different autonomous systemMetrics may vary in different autonomous system◦ Flooding between different autonomous systems is

    very hard

    20

  • Routing information◦ Sequence of the autonomous systems to be

    traversed to reach the destination◦ Policies may be used to choose autonomous systemPolicies may be used to choose autonomous system

    to favor or to avoid

    Without routing metrics◦ No problem of inconsistency between autonomous

    systemssystems◦ No value for the cost to reach the destination

    21

    Distributes information about the autonomous systems to be used to reach the destination

    Initially, BGP routers exchange the complete routing tables

    Afterwards only updates are distributed to the neighborAfterwards, only updates are distributed to the neighbor autonomous systems

    Each message contains at least:◦ Source of the information (RIP, OSPF, …)◦ List of autonomous systems to reach the destination (AS-PATH)◦ Next Hop

    If h h h h d i i hIf there are more than one path to the destination, the autonomous systems traversed may me analysed and the best one selected according to policies

    22

    Routing protocol

    Routing algorithm

    Routing metrics

    Routing scope

    23

    Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    24

  • Nowadays the Internet is used in almost all everyday situations, ranging from the simple email exchange and web browsing, through videoconferencing and distributed games upvideoconferencing and distributed games, up to distributed simulations and virtual reality.

    This wide variety of applications has brought up the limitations of the best-effort service provided by the original Internet.

    25

    Why Quality of Service?F li i◦ For applications

    Improved performanceSeamless utilization

    ◦ For providersResource OptimizationOver-provisioning avoidancep g

    ◦ For usersCost controlUtilization of modern applicationsUtilization of modern applications

    26

    IETF flavors◦ Integrated Services◦ Differentiated Services◦ Signaling◦ Signaling

    RSVPNSIS

    TechnologyIEEE 802 11◦ IEEE 802.11e◦ IEEE 802.16d◦ IEEE 802.16e

    27

    Quality of Service routing aims at selecting suitable paths for the different types of trafficsuitable paths for the different types of traffic generated by diverse applications based on information about the state of the network with h bj i f i i h ffithe objectives of improving the traffic

    performance and network resource utilization.

    The first objective concerns the level of serviceoffered to the end-user.

    The second objective pertains to the revenueobtained by Internet Service providers.

    28

  • Simplicity: minimize the number of signalling d h d d hmessages and the memory needed to store the

    routing tables

    Robustness: avoid forwarding errors that may lead to packet loss, loops and instability

    Fast convergence time: react promptly to network changes and provide rapidly all routers with achanges and provide rapidly all routers with a consistent vision of the network

    29

    Stability: adapt in a limited manner to the d i f h k i h i idynamic of the network without causing routing oscillations

    Scalability: be able to scale to large networks and high traffic volumes

    Resiliency: support alternate paths / mechanisms to be used in case of failureto be used in case of failure

    30

    d ?How can we do it?

    How much does it cost?How much does it cost?

    Do we need it?

    Is it feasible?

    Why not overprovisioning?

    31

    It’s all about metrics and algorithms!

    ◦ Anything else?

    Besides, it is about applications, topologies, users, types of networks, ISP policies, business models, technologies, IETF, QoS models, … Q ,

    You name it!

    So, let’s start smoothly ☺

    32

  • Traditional routing algorithms

    ◦ Compute the shortest path to the destination

    ◦ All packets for a certain destination are forwarded to the same NH

    How to support different QoS needs?

    33

    To select paths suitable for traffic with diverse prequirementsImprove network utilization

    QoS parametersTraffic requirements

    D lExplicit QoSparameters

    DelayJitter

    Nº hopsLosses

    Classes of service Bandwidth

    34

    Quality of Service Routing (QoSR)Q y g (Q )

    Multi-Constrained Path ProblemT fi d th P b t d d d h◦ To find a path P between nodes s and d, such as

    ( ) , 1, 2,...,i i

    w P L i q≤ =

    ◦ wi(P) - weight of path P for metric i◦ Li – maximum metric value for a path to be

    ( )i i

    q

    Li maximum metric value for a path to be admissible

    P is an admissible path35

    P is an admissible path

    AB

    Restrictions (from A to B):

    D l (D) 25 A il bl b d id h (BW) 60 36Delay (D) = 60

  • Routing granularitydd◦ Destination address

    ◦ Destination address, class of service◦ FlowRouting decision◦ Hop-by-hop◦ Source-basedSource basedPath computation◦ Pre-computation

    O d d◦ On-demand◦ Hybrid

    37

    Routing metricb f h◦ Number of hops

    ◦ Available bandwidth◦ DelayDelay◦ Losses◦ …

    Algorithm◦ Distance vector◦ Distance vector◦ Link state◦ …

    38

    Destination address◦ All the packets for the same destination are

    forwarded to the same NH◦ No alternate paths are used

    Destination address, class◦ All the packets of the same class for the same

    destination are forwarded to the same NHdestination are forwarded to the same NH◦ Alternate paths per class

    Flow

    + load balancing+ state+ complexityFlow

    ◦ All the packets of the same flow are forwarded to the same NH

    + complexity

    39

    Hop-by-hop Sourcep y p+ Scalability+ Response time

    Loops may occur

    + More complex algorithms can be used- Inaccuracy- Loops may occur

    - Complex QoS routing - Inaccuracy- Scalability

    Signaling is needed Most used for QoSR

    40

  • Pre-computation+ Setup time- Path computation for all requirements and destinations

    On-demand+ Network state is up-to-datep+ Only the needed path is computed- Processing overhead if the request arrival rate is high

    41

    QoSR: on-demand or hybrid approaches

    1. Information distribution communication overheadoverhead

    2. Metric selection path computation algorithm complexity

    3 Routing table structure complexity and storage3. Routing table structure complexity and storage

    4. Stability

    5. Inaccuracy

    42

    Which information?◦ TopologyTopology ◦ Resources available◦ Congestion state

    H ?How?◦ LSAs extensions◦ Probing◦ SignalingSignaling

    When?◦ Topology changes

    N t k t t h◦ Network state changes◦ Periodically◦ When needed

    43

    QoSR causes communication resource consumptionh h f f h d◦ the increase in the amount of routing information exchanged

    ◦ the amount and size of routing messages◦ the number of routers that must receive the routing messages

    Trade-off: up-to-date data/communication overhead

    Solutions◦ Quantification: average, moving average

    Th h ld b d i i f d t◦ Threshold based emission of updates◦ Selective flooding◦ Hierarchical organization

    44

  • 1. Information distribution communication h doverhead

    2 Metric selection path computation algorithm2. Metric selection path computation algorithm complexity

    3. Routing table structure complexity and storage

    4 Stability4. Stability

    5. Inaccuracyy

    45

    Applications have multiple requirements

    Paths must satisfy multiple requirementsPaths must satisfy multiple requirements

    The complexity of the path computation algorithm depends on the composition rule of the metrics used

    46

    Metric composition rulesp

    ∑=n

    ilmpm )()(Additive Number of hops∑=i

    ip1

    )()( p

    ∏=n

    ilmpm )()(Multiplicative Losses

    nilpm 21)min()( ==Concave Bandwidth

    ∏=i

    ip1

    )()(p

    nilpm i ,...,2,1),min()(Concave Bandwidth

    47

    Problem◦ To find a path which satisfies two or more

    additive or multiplicative constraints is NP-completecomplete◦ What can we do?

    ?

    48

  • Algorithmic Approaches

    ◦ Exact AlgorithmsNo complexity reduction, optimal solutions

    ◦ Heuristics AlgorithmsComplexity reduction, near optimal paths

    ◦ Hybrid AlgorithmsFlexible approach to be used under multiple circumstancescircumstances

    49

    Bandwidth Restricted Paths (BRP)Bandwidth + additive metricBandwidth + additive metric

    Metric orderingSequential filtering

    Restricted Shortest Paths (RSP)2 additive metricsHeuristics

    Metric orderingMetric combination

    ◦ Extensions to Bellman-Ford or Dijkstraalgorithms

    H i i

    50

    Heuristics:Reduce algorithm complexity/processing overhead

    Metric ordering◦ To identify the most important metric◦ To select the best path according the first metric◦ In case of a tie, select the best path according to the p g

    second metric

    L d b l iShortest-widest path • Load balancing• Better performance with light load• Damages best-effort traffic performance

    • Limit resource consumption• Better performance with high load• More resistent to routing information inaccuracy

    Widest-shortest path

    51

    Sequential filteringq g◦ To exclude all the links which have less bandwidth than

    a certain threshold – Pruning policyOn-demand path computation: the request depicts theOn demand path computation: the request depicts the valuePath pre-computation: to establish value ranges

    ◦ To select the shortest path according to the second metric on the pruned graph

    52

  • Metric ordering◦ To find feasible paths according to one constraint◦ Select the best/optimal path according to the second

    constraint

    ◦ Example: Delay-Constrained Least Cost (DCLC) problemNetwork: G(V,E)Network: G(V,E)Edge e = (u,v) ∈ E has two associated metrics: Cost - c(e) and Delay - d(e)Given a source node s and a destination node d, P(s, d) is the set of all paths from s to d.

    ∑∈

    =iPe

    i ecPc )()( ∑∈

    =iPe

    i edPd )()(' )(:)( PddsP d lΔ≤

    53

    )(min),('

    :

    )(:),(

    iDCLC

    PddsP

    PcdsPP

    delayi

    i∈

    Δ≤

    Metrics combinationGi ddi i i d l d( ) d◦ Given two additive metrics delay – d(e) and cost –c(e) for a link e ◦ Where α and β are the relative weights of each

    imetric

    += edecew )()()( βα

    ∑∈

    =

    +=

    PeewPw

    edecew)()(

    )()()( βα

    ◦ Do you find any problems with this approach?

    54

    1. Information distribution communication overheadoverhead

    2. Metric selection path computation algorithm complexity

    3 Routing table structure complexity and storage3. Routing table structure complexity and storage

    4. Stability

    5. Inaccuracy

    55

    Large routing tableLong look p◦ Long lookup

    ◦ Limited scalability

    h d ?What to do?

    ◦ Store only the best pathy p◦ Use a normal routing table for BE and on-demand

    path computation for QoS flows◦ Use class-based routingg

    56

  • Basic forwarding does destination-based packet classification and a corresponding Forwarding Information Base lookupand a corresponding Forwarding Information Base lookup

    QoS-aware packet classification depends on the traffic classification used in the networkclassification used in the network◦ Flow classification - there is the need to keep in the FIB one entry

    for each flow◦ MPLS networks - a layer two lookup is done and the classification◦ MPLS networks a layer two lookup is done and the classification

    is only made using a label

    SolutionsSolutions◦ Efficient packet classification◦ Fast hardware lookup methods of commercial routers

    57

    1. Information distribution communication h doverhead

    2 Metric selection path computation algorithm2. Metric selection path computation algorithm complexity

    3. Routing table structure complexity and storage

    4 Stability4. Stability

    5. Inaccuracyy

    58

    Instability occurs when reaction is excessive

    Sources of instability◦ Congestion based metricsCongestion based metrics◦ Update distribution policies◦ Network topology◦ Traffic patterns◦ Traffic patterns◦ Mobility

    59

    Approaches to avoid instability

    ◦ Distribution of quantified metrics◦ Load balancing◦ Load balancing◦ Hybrid routing

    Long duration flows: on-demandShort duration flows: pre-computation

    ◦ Route-pinning◦ Class-pinningClass pinning

    60

  • Advertisement of metrics that are quantified instead of advertising instantaneous valuesadvertising instantaneous values◦ Contributes to routing stability, but◦ Reduces the dynamic nature and the adaptation capabilities of the

    routing protocol

    ◦ It is necessary to configure the mechanism of metrics quantification in order to achieve a fruitful trade-off between routing stability and routing adaptation

    Two timescales for metrics evaluation◦ Long-term timescale, end-to-end delay information is used for

    path pre-computationSh t t ti l l l i d l i f ti i d t◦ Short-term timescale, local queuing delay information is used to adjust the pre-computed paths to handle temporary traffic bursts without the need of computing all the paths in the network

    61

    Hybrid routing (1)◦ Long duration flows: on-demand ◦ Short duration flows: pre-computation

    ◦ Dynamic routing is only used for long-lived flows reduces communication and processing overhead

    ◦ Long lived flows avoid successive path computations Long lived flows avoid successive path computations contributing to stability

    Hybrid routing (2)Hybrid routing (2)◦ Long duration flows: smoothed metric◦ Short duration flows: actual metric

    62

    1. Information distribution communication h doverhead

    2 Metric selection path computation algorithm2. Metric selection path computation algorithm complexity

    3. Routing table structure complexity and storage

    4 Stability4. Stability

    5. Inaccuracyy

    63

    It is desirable that the state kept at all routers remains up-to-date and that it reflects the complete and detailed state of the network

    However, is this possible?

    64

  • Sources

    ◦ Reduced frequency of updates

    ◦ Information aggregation in hierarchical networks

    ◦ Delay introduced in large networks

    ◦ Utilization of estimatesUtilization of estimates

    65

    Due to this wide range of factors, the global state that is kept by each router is just an approximation of the real actual state

    When the path computation algorithms use this inaccurate information as if it was exactthis inaccurate information as if it was exact, their performance can be highly damaged

    66

    Approaches

    ◦ State of the network represented as probability functionsfunctions

    ◦ Probing instead of flooding

    ◦ Multiple-path routing

    67

    State of the network represented as probability ffunctions

    ◦ QoS routing algorithms that cope with inaccuracy in routingQoS routing algorithms that cope with inaccuracy in routing information need to be adapted to make path computation based on information that is neither complete nor exact.

    68

  • Problem Scheme Metrics AlgorithmBandwidth-C t i d P th

    Logarithmic-BCP-ISI Logarithmic function of the probability th t li k d t

    Shortest-Path Constrained Path under Inaccurate State Information (BCP-ISI)

    that a link can accommodate a connection

    (e.g. Dijkstra)

    Relaxed-BCP-ISI Mean and variance of the bandwidth available in the link

    Modified Dijkstra

    Safety-Based-Routing(SBR) Safety metrics: estimation of the Safest-Shortest y g( ) ymaximum change of bandwidth until the next update

    Sa est S o testPath or Shortest Safest Path

    Delay-Constrained Path under

    Basic-Delay-Constraint (BDC) p.d.f of the minimum delay the link can provide plus the propagation delay

    Link-State for i lPath under

    Inaccurate State Information (DCP-ISI)

    provide plus the propagation delay special cases

    Random-Basic-Delay-Constraint (RBDC)

    Transformation of the mean and variance of the queuing delay

    Modified Dijkstra

    Transformed-Delay-Constraint (TDC) p.d.f of the available residual rate on the link

    Algorithm min-PRlink PR

    Bandwidth-Delay Constrained Path under Inaccurate State Information

    Association of Relaxed-BCP-ISI and Random-Basic-Delay-Constraint

    Mean and variance of the bandwidth available in each link and transformation of the mean and variance of the queuing delay

    Link-State for special cases

    (BDCP-ISI)

    69

    Probing instead of flooding

    ◦ The utilization of probing avoids the staleness of link-state information because the probes gather the most recent state information.

    70

    Multiple-path routingScheme Metrics AlgorithmRandom-Safety-Based-Routing (R-SBR) Safety metrics Randomized extension to Safest-

    Shortest Path (Modified Bellman-Ford))

    Randomized Bandwidth-Delay Constrained path (R-BDC) Safety metrics and delay (transformed in number of hops)

    Randomized Multiple-path

    Shortest-K-Widest Path (SKWP) Bandwidth Pruned K-Shortest Path (Modified Dijkstra)

    Widest-K-Shortest Path (WKSP) Bandwidth Pruned K-Shortest Path (Modified Dijkstra)

    R d K Wid t P th (RKWP)Random-K-Widest Path (RKWP) Bandwidth Pruned K-Shortest Path (Modified Dijkstra)

    Bypass Based Routing (BBR) Obstruction metrics

    Shortest-Obstruct-Sensitive Path (SOSP) and the Obstruct-Sensitive-Shortest-Path (OSSP)

    71

    Shortest-Path (OSSP)Proportional Sticky Routing (PSR) Flow blocking

    probability Weighted-Round-Robin-Like Path (WRRLP)

    QoSR-DiffServQoSR complements DiffServ by selecting different paths for◦ QoSR complements DiffServ by selecting different paths for different traffic classes

    ◦ Traffic differentiation in routers performed by DiffServmechanismsmechanisms

    QoSR-IntServ◦ QoSR selects paths for PATH messagesQoSR selects paths for PATH messages◦ RSVP reserves resources

    QoSR-MPLSQoSR MPLS◦ QoSR selects paths◦ MPLS uses LDP to establish LSPs

    72

  • Intra-domain QoSRQ◦ Single administrative control◦ Flexible, efficient

    Inter-domain QoSR◦ Multiple administrative control◦ Multiple administrative control◦ Simple, stable and inter-operational

    Different requirements!

    73

    BGP extensions◦ QoS support

    Traffic control schemesTraffic control schemes◦ Internet-wide

    Overlays◦ End-system

    Multi-homingSmart routingSmart routing

    74

    QoS BGP extensionsNew QoS attributes distributed in BGP UPDATE messages

    Inband signalling results in low converge and instability problems Dynamic changes on network state are notDynamic changes on network state are not considered

    75

    Traffic control schemes◦ Overlay network-based mechanisms

    A large number of overlay entities is placed across several ASesThe role of these nodes is to periodically monitor the performance and availability of paths between them

    However, since overlays do not control de beahaviour of the d l i i f t t Q S t t b dunderlying infrastructure, QoS support may not be ensured

    76

  • Traffic control schemes INC3Destination prefixes: p1, p2, p3, p4

    Multi-homingConsists on the increase of Internet connectivity by contracting multiple broadband lines

    INP1 4 5

    6contracting multiple broadband lines

    Smart Route Controller (SRC)1

    3Used by multi-homed stub ASes, as they provide a holistic way to solve local end-to-end traffic challenges through shifting some traffic between ISP i h i l

    INP2 INP3

    23

    INP4

    INP5

    ISPs in short timescales

    SRC SRC

    77

    INC1 INC2

    Pros:To find paths s itable for different t pes of traffic◦ To find paths suitable for different types of traffic

    ◦ Improve network utilization

    CCons:◦ Communication, processing and storage overhead◦ Complex implementation◦ Instability may occur

    78

    Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    79

    Routing Protocols

    Routing metrics

    Quality of Service Routing Protocols

    80

  • AKA table driven - From the “wired world”: Paths are pre computed◦ Paths are pre-computed

    ◦ Updates are exchanged periodically◦ For networks with low mobility and frequent data

    transmissiontransmission

    + Response time- Communication overheadCommunication overhead- Processing overhead due to frequent path computation and

    computation of “useless” paths to destinations which are not popular

    DSDV - Highly Dynamic Destination-Sequenced Distance-Vector Routing OLSR - Optimized Link State Routing protocol

    81

    AKA on demand – From the “signalling world”h d d◦ Paths are determined upon request

    ◦ For networks with high mobility and infrequent data transmission

    + Node lifetime+ Bandwidth since requests are only sent on demand- Bandwidth when flooding is used- Response time due to the route discovery mechanism

    DSR- Dynamic Source Routing ProtocolAODV- Ad Hoc On-Demand Distance VectorDYMO - Dynamic MANET On-demand

    82

    A combination of pro-active and reactivell d f d d d◦ Typically proactive in defined zones and reactive outside

    + The best of both worlds- Creation and management of zones/clusters

    ZHLS - Zone-based Hierarchical Link StateZRP - Zone Routing ProtocolCBRP - Cluster Based Routing Protocol

    83

    MAC parameters Has routing h◦ Traffic load

    ◦ Interference◦ Noise

    anything to do with these?

    ◦ Noise◦ Topology

    MAC performance can be considerably impacted by routing decisions

    MAC / Routing Cross-layer

    metrics

    84

    metrics

  • Hop countE i+ Easy computation

    - Does not consider the characteristics of wireless environments (different link transmission rates, loss

    i )ratios)- Does not consider congestion level

    Expected Transmission Count Metric (ETX)+ Takes into consideration link loss ratios and

    interference between the successive links of a pathinterference between the successive links of a path- Does not consider different transmission rates- Does not include link utilization

    85

    Expected Transmission Time (ETT) Intra-flow interference: Inter-flow interference:+ Evolution of ETX+ Takes into account link loss ratio and bandwidth- Does not consider channel interference

    Intra flow interference:

    Interference of adjacent links using the same channel

    Inter flow interference:

    Interference between multiple flows from one or multiple sources

    Does not consider channel interference

    Weighted Cumulative ETT (WCETT)+ Computes ETT over a path+ Considers intra-flow interference

    Does not consider inter flow interference- Does not consider inter-flow interference

    86

    Metric of Interference and Channel Switching (MIC)(MIC) + Considers intra-flow interference – channel diversity+ Considers inter-flow interference – ETT weighted by the g y

    number of nodes it interferes with- Overhead needed to maintain up to date information- Does not consider traffic load in each nodeDoes not consider traffic load in each node

    Multiple-path routing metricsh l l h ( )◦ Channel Aware Multipath (CAM)

    ◦ Weighted Interference Multipath (WIM)

    87

    QoS extensions for AODV (QAODV)

    QoS extensions to OLSR (QOLSR)

    QoS extension to DYMO (DYMOQoS)

    88

  • Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    89

    Routing & mobility

    Routing for resilience

    Routing & cross-layer design

    Routing and forwarding security in MANETs

    Routing scalability

    90

    Wireless networks disseminationk◦ Network types

    Cellular Networks (with infrastructure)Ah Hoc NetworksSensor Networks

    ◦ Different technologiesUMTS802.11Bluetooth…

    ◦ Integration of technologies3rd and 4th Generation networks

    91

    Challenges◦ Limitation of devices

    Low processingLow resourcesLow resourcesLow memoryLow autonomy (energy)Radio interferenceRadio interference

    ◦ High mobilityInaccurate path information

    ◦ No centralized management

    92

  • In networks failures may occur:Due to:◦ Due to:

    hardware degradationmalicious attacksmaintenance operationsmaintenance operationshuman errorsaccidentsnatural disasterstopology changes (mobility)

    ◦ For variable amounts of time:short-termed (transient failures)medium-termed failures (updates/reboots)long-termed failures (fibber cut)

    93

    Check this paper:

    ◦ Ian F. Akyildiz, Xudong Wang, “Cross-Layer Design in Wireless Mesh Networks”, IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 57, NO 2 MARCH 2008NO. 2, MARCH 2008

    94

    Routing BasicsQuality of Service RoutingRouting in Wireless Mesh NetworksResearch ChallengesProjects

    95

    Study of Routing Mechanisms for Mobile Ad-hoc Networks – David PalmaQoS Routing in Wireless Mesh Networks –Vinicius BorgesVinicius BorgesInterference-aware Routing Metrics for Wireless Mesh Networks – Daniel PereiraWireless Mesh Networks Daniel PereiraAnalysis of Clustering Schemes for Mobile Ad-Hoc Networks – Luis ConceiçãoçRouting and Forwarding Security in WMNs –Viviane Lima and Vitor Ruivo

    96

  • Q3M - QoS Architecture for Multi-user Mobile Multimedia Sessions in 4G Systems

    E Q S E d E d Q S S OEuQoS – End-to-End QoS Support OverHeterogeneous Networks

    WEIRD – WiMAX Extensions to Isolated Data Research NetworksResearch Networks

    97

    GINSENG◦ Performance Control in Wireless Sensor Networks

    Use of WSNs in industrial environments where performance assurances are criticalperformance assurances are critical.

    MICIE◦ Tool for systemic risk analysis and secure mediation of data

    exchanged across linked CI information infrastructuresTo design and implement a so-called "MICIE alerting system" that o des g a d p e e t a so ca ed C a e t g syste t atidentifies, in real time, the level of possible threats induced on a given CI by "undesired" events happened in such CI and/or other interdependent CIs

    98

    David Palma, Marilia Curado: "NODRoP, Nature Optimized Deferred Routing Protocol", INFOCOM'09, 28th Annual Joint Conference of the IEEE Computer and Communications Societies Student Workshop 2009Societies - Student Workshop, 2009

    Alexandre Fonte, Marilia Curado, Edmundo Monteiro, “Interdomain quality of service routing: setting the grounds for the way ahead”, Annals of Telecommunications, Springer Paris, ISSN 0003-4347, Volume 63, Numbers 11-12 / December, 2008, pp 683-695

    Daniel Pereira, Alicia Trivino Cabrera, Marilia Curado, “Analysis of Metrics for Routing Optimization in Wireless Mesh Networks”, International Workshop on Traffic Management and Traffic Engineering for the Future Internet (FITraMEn 08), Porto, Portugal, 11-12 December, 2008

    Alexandre Fonte, José Martins, Marilia Curado, Edmundo Monteiro: Stabilizing Intelligent Route Control: Randomized Path Monitoring, Randomized Path Switching or History-Aware Path Switching?. In Proc. of MMNS 2008, Samos, Greece, September 2008

    Masip-Bruin, X., M. Yannuzzi, J. Domingo-Pascual, A. Fonte, M. Curado, E. Monteiro, F. Kuipers, P. Van Mieghem, S. Avallone, G. Ventre, P. Aranda-Gutierrez, M. Hollick, R. Steinmetz, L. Iannone and K. Salamatian, 2006, "Research Challenges in QoS Routing", Computer Communications, Vol. 29, pp. 563-581.

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    David Palma, Marilia Curado, “Inside-out OLSR Scalability Analysis” submitted to the 7th International Conference onAnalysis , submitted to the 7th International Conference on Wired / Wireless Internet Communications, University of Twente, The Netherlands, May 27-29, 2009

    Viviane Lima, Vitor Ruivo, Marilia Curado, “Securing Wireless Mesh Networks: a Winning Combination of Routing and Forwarding Mechanisms” submitted to the First IFIPForwarding Mechanisms , submitted to the First IFIP Conference on Network and Service Security, Paris, France, June 24-26, 2009

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  • ili @d [email protected]://cisuc.dei.uc.pt/lct/

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