March 13, 2003 Routing Functional Components Steven D. Jones (JHU/APL) Chunyue Liu (CCNY) Tarek Saadawi (CCNY) I-Jeng Wang (JHU/APL)

March 13, Motivation and Objectives Develop a component-oriented framework for design and analysis of routing protocols  Most protocols can be constructed by common key components and many share fundamentally the same mechanisms/algorithms for specific components.  Analysis and comparisons based on simulation of entire protocols provide inadequate characterization of performance.  Component-oriented approach can provide insights into key aspects of protocols that lead to specific performance.  New techniques can be developed for specific component to address the new challenges arise in applications Establish a framework for dynamic component configuration to support heterogeneous routing  Component-wise reconfiguration provides more flexibility and can support the wider spectrum of operating conditions for tactical network

March 13, Routing Functional Components Route Representation & Determination Neighbor Discovery & Maintenance Packet Forwarding Route Information Initialization Primary Functions Route Discovery Information Dissemination Supporting Functions Route Maintenance Failure Response Dynamic Route Management

March 13, Route Representation and Packet Forwarding Route Representation & Determination: Distributed information necessary to compute routes and the underlying algorithms  Mechanisms:  Source routes  Link state  Routing table  General next-hop utility Packet Forwarding: Mechanism to forward data packet based on route information  Largely driven by route representation  More significant when multiple routes are available

March 13, Neighbor Discovery and Maintenance Dynamically maintain the knowledge of necessary neighborhood information  Information from link layer  Hello messages  Information from information dissemination in support of routing  Information from data transmission Might include information beyond the 1-hop neighbors for some protocols  For example, multi-points relays for OLSR

March 13, Route Information Initialization Properly initialize route information under relevant constraints when a network is deployed or a new routing domain is configured  Constraints can include time, overhead, energy, stealth  Prior information useful and resources required to configure initialization is typically available when a tactical network is deployed Mechanisms  Partial or complete  Using route discovery driven by traffic models derived from IER

March 13, Dynamic Route Management: Route Maintenance and Failure Response Route Maintenance: Properly update route information to address dynamics  Mechanisms:  Triggering conditions Event-driven: time-out, threshold on route quality, demand-driven Periodic  Specific actions Route discovery Information dissemination Failure Response: Respond to the detected loss of a link due to failure, mobility, or jamming  Mechanisms:  Active: properly update the route information to repair affected routes or compute alternative routes (TBRBF).  Passive: remove invalid route information due to the failure (AODV or DSR).  Mixed

March 13, Mapping Protocols to Functions Route Representation Packet Forwarding Neighbor Discovery & Maintenance Route Information Init. Route Maintenance Failure Response AODVRouting Table:  At most one entry for each dest.  Timer  Sequence # Table entriesNot explicit  On-demand w/ route discovery  Timer-based deletion for stale routes Notify all sources using failed link via RERR DSRSource Routes  possibly multiple routes in cache  min-hop route  salvaging Not explicitOn-demand w/ route discovery  Notify source node following the reverse route when the packet meet the failed link)  Gratuitous repair TBRPF  Reportable source tree  Link state  Rely on partial topology  Hop-by-hop  Hello  Differential Hello Modified Dijkstra’s alg.  Periodic updates  Differential updates Report in differential updates Ant Routing Next-hop utility:  Multiple routes  utility can reflect general qualities of the route Max-utility next hop Hello messageNo explicit  periodic update with randomized agents  on-demand update  modify utility via backward agents  Local repair to salvage the packets

March 13, Plan for the Remaining Year Develop clear definition of routing functional components  More detailed mapping of protocols to components  Incorporate multicast protocols  Define interfaces among components and with other layers Characterize the impact of component designs to critical routing performance metrics  Define key mechanisms and design parameters for each components  Identify routing performance metrics that are highly correlated to each component  Identify specific operating conditions under which specific component designs are required for satisfactory performance  Based on existing results, analytical techniques and focused simulation of existing protocols