Ppt multicast routing
- 1. Multicast routing state-of-the art, standardisation, open issues and research directions Dr. Ilka Miloucheva Fraunhofer Center for Advanced Satellite communication (SATCOM) & Fachhochschule Bonn-Rhein-Sieg
- 2. Topics Classification of multicast routing protocols in Internet with fixed infrastructure Optimised and Overlay Multicast Routing Inter-domain Routing Multicast Routing for Mobile Internet Ad hoc multicast routing QoS based Routing Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 2
- 3. Classification of multicast routing protocols in Internet (1) Classification criteria: Path construction and maintainance Multicast routing protocols characterised by: - multicast tree building algorithm, - maintenance of the tree structure, - packet forwarding, - failure discovery and recovery Objective of multicast routing Constrained cost minimization delivering multicast data while meeting an upper bound for end-to-end delay Multicast routing algorithms designed according application and group requirements / constraints Source based Shortest path multicast tree always routed by the source Delay optimisation during multicast forwarding from source to the receivers, but possible additional tree maintenance overhead for specific group communication models Distance vector: DVRMP, PIM-DM Link state: MOSPF Core based Shortest path multicast tree routed at the core Single core: CBT, PIM-SM Multi-core: OCBT, “Sender-to-many” Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 3
- 4. Classification of multicast routing protocols in Internet (2) Core based protocols and core selection algorithms Choice of core – dependent on Topological location of the multicast group members Delay in data forwarding, Bandwidth Protocol control overhead Preferable to source based trees in case of multiple multicast sources Core selection algorithms Single core and multiple-core, Constrained and unconstrained Centralized (GREEDY, opt_tree) and distributed Topology based Group based Criteria maximum and average distance form the core to group members Diameter of the tree routed by the core Minimum and maximum cost of the tree Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 4
- 5. Optimised and overlay multicast routing (1) Bypass the traditional multicast routing deployment Bridging service between several multicast-capable areas running different multicast routing protocols (IPv4 and IPv6) Unicast / Multicast Reflector and Punctual Tuning Host having access to unicast routing contacts a reflector (user level gateway between a multicast enabled network and unicast hosts) Limited time and group size UMTP, MTunnel Permanent Tunneling Tunneling at router level with IP encapsulation for the whole multicast group Mrouted DVMRP Automatic Overlay Multicast Multicast by end-systems implementing the routing approach Overlay topology under complete control and application dependent Underlying topology is hidden Membership knowledge centralised (source), RP or distributed among members, partial and full knowledge “Mesh” and “tree first” distributed algorithms Narada – overlay structure on top of unicast Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 5
- 6. Optimised and overlay multicast routing (2) Dedicated multicast strategies Gossiping for Peer-to-peer communications Gossiping technique like Scribe can be used for highly robust state distribution Each node increases the group membership knowledge horizon by one hop RP maintains the whole knowledge Technique limited to small data transfer Dedicated new group communication routing service Needs for stable networking infrastructures and mobile ad hoc networks Dedicated way to distribute topology (distributed core routers) Scalability support: XCAST, Distributed Core Multicast (DCM), AMRoute (overlay mesh), ODMRP (source crates on-demand a mesh of sources), MAODV (on demand building of shared trees) Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 6
- 7. Optimised and overlay group multicast routing (3) Approaches for scalable multicast routing: Routing states reduction Reducing the routing states by tunneling and routing state aggregation on top of PIM or CBT Encoding of list of destination addresses in a branching node Simple Explicit multicast Partially elimination of routing states by using of branching routers in the multicast tree State aggregation: REUNITY, SEM, HBH Elimination of routing states completely by explicitely encoding the list of the destinations in the packets instead of using of multicast address Explicit Multicast: Xcast, Gxcast Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 7
- 8. Inter-domain routing Multcast routing between domains needs further concepts to support content delivery Currently, no scalable solution for inter-domain multicast routing Configuration complexity of current connection of different domains for inter-domain multicast based on MBGP (Multiprotocol Extension to BGP) Used to announce different multicast and unicast routers MSDP (Multicast Source Discovery Protocol). Exchange active source information among different domains Inter-domain support of emerging multicast applications – on- demand multicast for content delivery Hop-by-Hop Multicast Routing Protocol proposed Source specific channel abstraction Unicast routing asymmetries impact the multicast tree construction Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 8
- 9. Multicast routing for Mobile Internet DAIDALOS approach: Integration of IETF standardised multicast group communication and routing protocols (MLDv2, PIM-SM) in Mobile IPv6 architecture Mobile Multicast routing in IPv6 Source mobility Client mobility Mobile Multicast routing in IPv6 PIM-SM with context transfer -> DAIDALOS solution Optimised routing in MIPv6 Candidate access router discovery Multicast routing on unidirectional inks Extension of MIPv6 with facilities to handle unidirectional links in interaction with RFC 3077) Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 9
- 10. Multicast routing in Ad hoc Mobile Networks (1) MANET protocols: dynamic collection of nodes with sometimes rapidly changing multi-hop technologies (low bandwidth wireless links) AODV – Multicast extension of On-Demand Distance Vector Discovers multicast routes on-demand using a broadcast discovery mechanism Builds a shared multicast routes on demand using a broadcast route discovery mechanism Shared bi-directional multicast tree ODMRP – On-demand multicast routing protocol Mesh based Forwarding group concept Soft states for maintaining group members Extension of MIPv6 with facilities to handle unidirectional links in interaction with RFC 3077) Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 10
- 11. Multicast routing in Ad hoc Mobile Networks (2) Ad hoc wireless protocols AMRoute – Ad hoc multicast routing protocol A tree based protocol Bidirectional shared multicast tree AMRIS – Ad hoc multicast routing protocol utilising increasing id numbers Establishes a shared tree for multicast forwarding Detects link disconnection by beaconing mechanism Heterogeneous mobile ad hoc networks Range based mobile Multicast CAMP – Core Assisted Mesh protocol Shared meshed stricture Nodes are duplex or simple mebers or no members Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 11
- 12. QoS based multicast routing Goal Finding a path satisfying routing requirements QoS of multicast tree (receiver perceived QoS) Function of group dynamic including QoS aware routing Tree rearrangement Core /tree migration (core selection) Multicast resource reservation models Source and Receiver driven QoS reservation Receivers with Heterogeneous QoS Partitioning of multicast requirements into local requests minimising the route tree cost QoS driven routing and resource reservation Integration of routing and resource reservation RSVP Integrated Multicast (RIM) Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 12
- 13. Multicast routing algorithms supporting QoS requirements Shortest path tree Minimum spanning tree Steiner Tree Constrained Steiner Tree Maximum bandwidth tree Trees based on heuristics to meet the delay and inter-receiver delay jitter constraints Tree rearrangement on response to Member Join / Leave Multicast context transfer Daidalos <meeting type>, <location>, <date> © The Daidalos Consortium, Page 13