optimized link state protocol version 2 assaf israel, eli nazarov, asi bross version 2 assaf israel,...

Optimized Link State ProtocolOptimized Link State Protocol

Version 2

Assaf Israel, Eli Nazarov, Asi Bross

Version 2

Assaf Israel, Eli Nazarov, Asi Bross

OLSRv2 - OverviewOLSRv2 - OverviewApplicability

mobile ad-hoc networks (MANET)

dynamic topology

100%> reliable environment (WiFi, WiMax)

nodes can be gateways to other networks

Characteristics

Table driven

proactive protocol

Build on top of MANET NHDP

Applicability

mobile ad-hoc networks (MANET)

dynamic topology

100%> reliable environment (WiFi, WiMax)

nodes can be gateways to other networks

Characteristics

Table driven

proactive protocol

Build on top of MANET NHDP

TerminologyTerminology

node

1-hop neighbor set

2-hop neighbor set

bidirectional link

interface

node

1-hop neighbor set

2-hop neighbor set

bidirectional link

interface

Mobile Ad-hoc NetworksNeighborhood Discovery Protocol


A solid base for the OLSRv2 protocol.

Objective - maintain 1-hop & 2-hop neighbors link state tables

Pros

Simplicity - only one type of messages

Generic - does not limit to type of connectivity technology

Cons

Effects bandwidth as messages are routinely transmitted

A solid base for the OLSRv2 protocol.

Objective - maintain 1-hop & 2-hop neighbors link state tables

Pros

Simplicity - only one type of messages

Generic - does not limit to type of connectivity technology

Cons

Effects bandwidth as messages are routinely transmitted


(cont.)


(cont.)Local Information Base - per node

Active interface - IP tuples set

Removed interface - IP tuples set

Interface Information Base - per interface

Link Set

Current & Recently lost 1-hop neighbors to this interface

Connection quality

Validation time

Local Information Base - per node

Active interface - IP tuples set

Removed interface - IP tuples set

Interface Information Base - per interface

Link Set

Current & Recently lost 1-hop neighbors to this interface

Connection quality

Validation time

Interface IP

eth0 192.168.2.20

eth1 192.168.4.67

Link Set - eth0

Target Interface Quality V-Time

192.168.2.34 - eth0 13609 ms

10.148.3.20 - eth2 15338 ms

128.3.41.98 - eth1 Lost -


(cont..)


(cont..)Interface Information Base (Cont.)

2-Hop Set

Each entry consist of 2-hop address & all of the addresses of the corresponding symmetric 1-hop neighbor

Each tuple records an address of recently lost 1-hop neighbor

Interface Information Base (Cont.)

2-Hop Set

Each entry consist of 2-hop address & all of the addresses of the corresponding symmetric 1-hop neighbor

Each tuple records an address of recently lost 1-hop neighbor

2-Hop Set - eth0

2-hop IP Reachable via

128.3.4.120 [ 192.168.2.34 , 10.148.3.20 ]

128.3.4.120 [ 10.148.5.1 ]

133.5.5.90 [ 192.168.2.34 , 10.148.3.20 ]


(cont.)


(cont.)

Neighbor Information Base

Neighbor Set - Neighbor tuples

List all IP’s of a single 1-hop neighbor

Lost Neighbor Set - Lost Neighbor tuples

Neighbor Information Base

Neighbor Set - Neighbor tuples

List all IP’s of a single 1-hop neighbor

Lost Neighbor Set - Lost Neighbor tuples

Neighbor Set

Local Interface Target Interface set

eth0 [ 192.168.2.34 , 10.148.3.20 ]

eth0 [ 10.148.5.1 ]

eth1 [ 192.168.2.34 , 10.148.3.20 ]

Lost Neighbor Set

Local Interface Target Interface set

eth0 [ 192.168.2.90 ]

“Hello” message“Hello” message

The only type of message in MANET NHDP

Generated by a node independently on each MANET interface

Identify the source interface but adds information of all other local interfaces

May be sent

Proactively - at a regular pre-defined interval

Dynamically - interval may be backed off to to congestion or network stability

Event driven - e.g new/lost/changed status link

The only type of message in MANET NHDP

Generated by a node independently on each MANET interface

Identify the source interface but adds information of all other local interfaces

May be sent

Proactively - at a regular pre-defined interval

Dynamically - interval may be backed off to to congestion or network stability

Event driven - e.g new/lost/changed status link

“Hello” message - Objectives

“Hello” message - Objectives

Advertise the router’s interface addresses to it’s 1-hop neighbors.

Advertise the router’s knowledge of each of its 1-hop neighbors.

Advertise the router’s interface addresses to it’s 1-hop neighbors.

Advertise the router’s knowledge of each of its 1-hop neighbors.

“Hello” message - Content“Hello” message - Content

Must contain all of the Local Interface Set IPs

For each interface, and every pre-defined Refresh-Interval Must send all relevant information in the Interface Link Set & Neighbor Information Base.

Validity Time for which the information is considered valid

periodically should contain the Interval Time for which messages are sent from the interface.

Must contain all of the Local Interface Set IPs

For each interface, and every pre-defined Refresh-Interval Must send all relevant information in the Interface Link Set & Neighbor Information Base.

Validity Time for which the information is considered valid

periodically should contain the Interval Time for which messages are sent from the interface.

“Hello” message - Processing

“Hello” message - Processing

Updates the receiver’s Interface Information Base

If an entry from the message source exists then the valid time is checked and updated accordingly

If an entry does not exist from the message source, a new one will be created

If a message contains information that a symmetrical link has been lost/created between the source and a third node the 2-hop neighbor, the 2-hop Set will be updated accordingly

Updates to the Neighbor Information Base may occur

Will cause generation of yet another Hello message

Hello message are not forwarded

Updates the receiver’s Interface Information Base

If an entry from the message source exists then the valid time is checked and updated accordingly

If an entry does not exist from the message source, a new one will be created

If a message contains information that a symmetrical link has been lost/created between the source and a third node the 2-hop neighbor, the 2-hop Set will be updated accordingly

Updates to the Neighbor Information Base may occur

Will cause generation of yet another Hello message

Hello message are not forwarded

MANET Neighborhood Discovery Protocol

Optional extensions

MANET Neighborhood Discovery Protocol

Optional extensions

Link quality

Jitter

Link quality

Jitter

OSLRv2 - Multi Point RelaysOSLRv2 - Multi Point Relays

Multipoint Relays (MPR)- Set of 1-hop neighbors which broadcast node’s packets.

MPR must have bi-directional like with the node - avoid uni-directional link problems.

The union of all neighbors of MPRs give the group of 2-hop neighbors of the node.

Multipoint Relays (MPR)- Set of 1-hop neighbors which broadcast node’s packets.

MPR must have bi-directional like with the node - avoid uni-directional link problems.

The union of all neighbors of MPRs give the group of 2-hop neighbors of the node.

Multi Point Relays (Cont.)Multi Point Relays (Cont.)

• OLSRv2 uses MPR’s to calculate routes to all known nodes.

• Route is a sequence of hops through MPRs.

• Last MPR is the target node or the target is a 1-hop neighbor of the last MPR.

• MPR Selector is a neighbor that selected this node as a MPR.

• OLSRv2 uses MPR’s to calculate routes to all known nodes.

• Route is a sequence of hops through MPRs.

• Last MPR is the target node or the target is a 1-hop neighbor of the last MPR.

• MPR Selector is a neighbor that selected this node as a MPR.

SignalingSignaling

Extends NHDP “Hello” messages to include the selected MPRs set of the source node.

For each 1-hop neighbor with symmetric link that is selected as MPR for this router.

TC messages

Includes a Set of all 1-hop neighbors that selected the sending node as an MPR.

Advertised Neighbor Set.

Attached Network Set.

Extends NHDP “Hello” messages to include the selected MPRs set of the source node.

For each 1-hop neighbor with symmetric link that is selected as MPR for this router.

TC messages

Includes a Set of all 1-hop neighbors that selected the sending node as an MPR.

Advertised Neighbor Set.

Attached Network Set.

Message Processing & Forwarding

Message Processing & Forwarding

TC messages may be processed and/or forwarded

Hello messages are available to OLSRv2 after NHDP process - Never forwarded.

TC messages may be processed and/or forwarded

Hello messages are available to OLSRv2 after NHDP process - Never forwarded.

OSLRv2 - DatabasesOSLRv2 - Databases

All MANET NHDP Tables - with extensions

e.g flags to indicate MPR and MPR selector in Neighbor set.

Topology Information Base

Processing & Forwarding Information Base

All MANET NHDP Tables - with extensions

e.g flags to indicate MPR and MPR selector in Neighbor set.

Topology Information Base


Topology Information BaseTopology Information Base

Advertised Neighbor Set

Includes addresses of neighbors that selected this node as MPR.

Symmetric 1-hop neighbors that are advertised through TC massages.

Derived from Neighbor Set.

Advertised Remote Router Set

Remote addresses of routers that transmits TC massages.

Contains all of their addresses.

Advertised Neighbor Set

Includes addresses of neighbors that selected this node as MPR.

Symmetric 1-hop neighbors that are advertised through TC massages.

Derived from Neighbor Set.

Advertised Remote Router Set

Remote addresses of routers that transmits TC massages.

Contains all of their addresses.Advertised Remote Router Set

Source IP IP List Sequence No’ Time

192.168.2.34 [ 192.168.2.34 , 10.148.3.20 ] 1234 14228 ms

Topology Information Base (Cont.)Topology Information Base (Cont.)

Topology Set

Topology information about the network.

Routing Set

Records a path to each destination.

Topology Set

Topology information about the network.

Routing Set

Records a path to each destination.

Topology Set Table

Destination IP Last hop Sequence No’ Time

128.3.4.120 192.168.2.34 1234 14228 ms

Routing Set Table

Destination IP Next hop Hops No’ Local Int’

128.3.4.120 192.168.1.5 10 eth0

Topology Information Base (Cont.)Topology Information Base (Cont.)

Attached Network Set

Records Information about networks attached to other routers or can be reached via those router.

Attached Network Set

Records Information about networks attached to other routers or can be reached via those router.

Attached network Set

Net IP Net Mask Router IP Hops No’ Sequence No’ Time

192.168.1.0

255.255.255.0

192.168.1.5 10 1234 14228

ms

192.168.2.0

255.255.255.192

192.168.2.34 3 1002 15542

ms



Used to ensure that each massage is processed and forwarded once, at most, per OLSRv2 interface

Before processing/forwarding a massage, we must first check that it wasn't processed/forwarded yet.This is done using the information stored in Processing & Forwarding Information Base.

Used to ensure that each massage is processed and forwarded once, at most, per OLSRv2 interface

Before processing/forwarding a massage, we must first check that it wasn't processed/forwarded yet.This is done using the information stored in Processing & Forwarding Information Base.



Received Set - per interface

Signatures of messages received on this interface.

Processed Set

Signatures of messages processed by the router.

Forwarded Set

Signatures of messages forwarded by the router.

Relay Set - per interface

Symmetric 1-hop neighbors which messages should be forwarded when received on that interface.

Received Set - per interface

Signatures of messages received on this interface.

Processed Set

Signatures of messages processed by the router.

Forwarded Set

Signatures of messages forwarded by the router.

Relay Set - per interface

Symmetric 1-hop neighbors which messages should be forwarded when received on that interface.

“Hello” message process by OLSRv2“Hello” message process by OLSRv2

Updates its Neighbor Information Base if it was chosen as a MPR for the originator router (MPR Selector)

In case of topology change the set of MPRs is recalculated.

Updates its Neighbor Information Base if it was chosen as a MPR for the originator router (MPR Selector)

In case of topology change the set of MPRs is recalculated.

TC messages processingTC messages processing

When TC message received:

Topology Set is updated.

Advertised Remote Router Set is updated.

Attached Network Set is updated.

The Dijkstra algorithm can be used to construct the Routing Set

When TC message received:

Topology Set is updated.

Advertised Remote Router Set is updated.

Attached Network Set is updated.

The Dijkstra algorithm can be used to construct the Routing Set

Packet routingPacket routing

When a packet needs to get from A to B it is sent to the next MPR as described in the Routing Set.

Each MPR will forward the packet to the next MPR in the route.

When a packet needs to get from A to B it is sent to the next MPR as described in the Routing Set.

Each MPR will forward the packet to the next MPR in the route.

Source

Target

MPR

MPR

MPR

MPR

MPR

optimized link state protocol version 2 assaf israel, eli nazarov, asi bross version 2 assaf israel,...

Documents

interface link set current

removed interface ip

solid base

olsrv2 protocol

transmitted slide

proactive protocol build

manet nhdp slide

networks characteristics