ECE 544 Project3 Group 9 Brien Range Sidhika Varshney Sanhitha Rao Puskuru

Assumptions and Address Scheme Assumptions End hosts can only connect to routers and only one router Same content available at multiple end nodes When data is requested, it is copied, not deleted from the content provider.

Bootstrapping and Discovery Algorithm Routers and end hosts boot up – Routers and end hosts send a “Hello” packet on all ports and waits for a response. End host keep track of ports where it received response, routers Discovery N - Routers discover other routers via N discovery packets with updated routing tables, every 30 seconds, “hello” packets every 30 seconds Router uses STP

Baseline Algorithm Content routing algorithm How are contents advertised? – Content Requesters send multicast request, content owners reply Broadcasts are only sent over ports that are part of the minimum spanning tree to end hosts How to route a content-request packet? - multicast How to choose the ‘best’, among multiple hosts having the same content? – second request is sent after response of first request, first router choosing best path How is the content actually delivered? One to Many multicast request Many to one unicast response One to One request to router with eligible content hosts One to one request from router to closest content host Direct unicast transfer from host to host

Data Transfer and Reliability Message Forward Request(contentname) – Multicast Get(contentname,requester,*contentsources) – Unicast, Sent to linked Router Get(contentname,requester,contentsource) – Sent from router to closest source Response(requester,closestcontentsource,contentdata) – Sent from content owner to source ARQ Scheme End-to-end – the routers will not require flow state Request - Stop-and-wait because it is a multicast request Get – Stop-and-wait because there is no variable data content/size Response - sliding window because actual data is being transferred

Advantages and Disadvantages Scalability? – The design is not scalable, because of the N <= 255 hosts. However, there is less overhead, because we are not implementing a layer 3 protocol Latency Example 1 is 16 Hops Example 2 is 16 Hops Example 3 is 32 Hops Not reliant on availability of single content server or host database Resilient to link failure

Packet Formats

Example Scenarios Use the example scenarios (from the Appendix) to highlight the key aspects of your proposal

Appendix: Network Architecture Refer to the following example scenarios for analysis purposes: H1 H2 H3 C1 C2 C3 R1R2R3R4 R5 Scenario get (content_C3)

H1 H2 C1 C2 C3 R5 H1 H2 C1 C2 C3 R5 Request -Broadcasted by R2 to R3 and R1 Response from H3 Get() with H2’s address as the destination address forwarded to R5 and R5 will forward it without any update Transfer of the content

Appendix: Network Architecture H1 H2 H3 C1 C2 C3 R1R2R3R4 R5 Scenario get (content_C2)

H1 H2 H3 C1 C2 C3 R1R2R3R4 R5 H1 H2 H3 C1 C2 C3 R1R2R3R4 R5 Request – From H1 is broadcasted by R2 to R5 and R3 Responses from H3 and H2 Get() from H1 with H2’s address as the destination address and other Content address also is forwarded to R1 and R1 will update the destination address with the closest Host and delete the other content addresses i.e. address of H2 Transfer of the content

Appendix: Network Architecture H1 C3 Scenario get (content_C1) H2H3 H4 C1 C2 C1

Request – From H1 is broadcasted by R13 to the respective routers Responses from H2, H3 and H4 Get() from H1 with H2’s address as the destination address and other Content addresses also is forwarded to R13 and R13 will update the destination address randomly from H2 or H3 and delete the other content addresses. Transfer of the content Source- Destination Distance Between them H1- H24 H1-H34 H1-H45