Optimized Link State Protocol Version 2 Assaf Israel, Eli Nazarov, Asi Bross Version 2 Assaf Israel, Eli Nazarov, Asi Bross

OLSRv2 - Overview 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 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 Networks Neighborhood 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

Mobile Ad-hoc Networks Neighborhood Discovery Protocol (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 InterfaceIP eth eth Link Set - eth0 Target InterfaceQualityV-Time eth ms eth ms eth1Lost-

Mobile Ad-hoc Networks Neighborhood Discovery Protocol (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 IPReachable via [ , ] [ ] [ , ]

Mobile Ad-hoc Networks Neighborhood Discovery Protocol (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 InterfaceTarget Interface set eth0 [ , ] eth0[ ] eth1 [ , ] Lost Neighbor Set Local InterfaceTarget Interface set eth0[ ]

“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 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 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 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 Link quality Jitter Link quality Jitter

OSLRv2 - 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.) 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 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 - 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 Processing & Forwarding Information Base

Topology 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 IPIP ListSequence No’Time [ , ] ms

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 IPLast hopSequence No’Time ms Routing Set Table Destination IPNext hopHops No’Local Int’ eth0

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 IPNet MaskRouter IPHops No’Sequence No’Time ms ms

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. 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.

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 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 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 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