CSC458H1 Lecture 10: OVERLAY-P2P
Document Summary
Ontop of multiple routers in underlying network. Providing a service, such as access to files. Ex. peer-to-peer, resource allocation determined by peers: routing overlays = major type of overlay networks. Custom path selection: resilient overlay networks: ip tunneling = creates virtual point-point (direct) btwn two separated nodes, encapsulate an ip packet inside another ip datagram. Node b sends the encapsulated packet to node e. Fragementation may occur w/ inner packet: ex. 6bone deploying ipv6 over ip4: secure communication over insecure links, creates logical link btwn beginning and end of insecure network. Src = tunnel entry, dest = tunnel exit. Gateway has a fixed ip address, tracks mobile"s address changes. Not widely deployed mbone tunneled between nodes. Should multicast be a network-layer service: end-system multicast = use end hosts to create multicast tree. Hosts receiving the data help forward to other end hosts. Server sends to host a, b which sends onto c, d.
