ECE 544 Project3 Ali Rostami Mohsen Ghassemi Mahmoud Ramezani-Mayiami

Assumptions and Address Scheme Naming scheme Devices: Contents: contents Assumptions End hosts can only connect to routers Single packet request/single packet response We don’t worry about fragmentation, rate control The routing cost is the number of hops from ReqHost to content holder File NameCID

Assumptions and Address Scheme Terminology Node Either a router or a host ReqHost The host that requests the content RepHost The host who replies to the request CID Content ID

Bootstrapping and Discovery Node Boot up Send advertisement packets to its neighbors to say “Hello!” Rescheduling its timer for the next round Discovery Content based distance vector Only care about the content! Advertisement packets are sent to neighbors at each timer expiration (e.g. 100 ms interval)

Bootstrapping and Discovery Packet Format ConReq ConRep TypeNo. of HopsPrev. HopCID ReqHost ID TypeNo. HopsReqHost IDCID Data

Bootstrapping and Discovery Packet Format Adv. Packet Max: 514 Bytes No Ack Packet! This is a connectionless protocol We only care about finding the content holder Getting “reliability” as a service from the lower layer.  Hop by hop stop and wait  Using the first project as the lower layer protocol TypeAdv. Src.No. of CID CID #1CID Cost #1CID #2CID Cost #2 ………… CID #254CID Cost#254CID #255CID Cost#255

Routing Tables CIDNext HopCostExp. Time CIDPrev. HopReqHostExp. Time Content lookup table (Routing table) Reverse route table When a router forwards ConReq to the next hop, it adds a reverse route entry to be able to find who requested this content Content lookup table is used to find the next hop towards the content holder

Content Lookup Table (CLT) It keeps route information for the nearest content holder (Distance Vector) Once a content is available at a closer host (lower cost), the CLT is updated These guarantee the best routs to all the available contents

Advantages and Disadvantages Advantages Distributed control mechanism Easy to implement Code reuse (from the first project!) Disadvantages Scalability - Flat addressing for Content

Appendix: Network Architecture H1 H2 H3 C1 C2 C3 R1 R2 R3 R4 R5 Scenario get (content_C3) CR1H2C3 H2 ConReq Packet CIDNext HopCostExp. Time C1R2321 C2R2424 C3R2424 Content Lookup Table (CLT) CIDReqHostPrev. HopExp. Time C3H2 30 Reverse Route Table

Appendix: Network Architecture H1 H2 H3 C1 C2 C3 R1 R2 R3 R4 R5 Scenario get (content_C3) CR2R5C3 H2 ConReq Packet CIDNext HopCostExp. Time C1R1223 C2R3327 C3R3327 Content Lookup Table (CLT) CIDReqHostPrev. HopExp. Time C3H2R531 Reverse Route Table

Appendix: Network Architecture H1 H2 H3 C1 C2 C3 R1 R2 R3 R4 R5 Scenario get (content_C3) CR3R2C3 H2 ConReq Packet CIDNext HopCostExp. Time C1R2323 C2R4227 C3R4227 Content Lookup Table (CLT) CIDReqHostPrev. HopExp. Time C3H2R232 Reverse Route Table

Appendix: Network Architecture H1 H2 H3 C1 C2 C3 R1 R2 R3 R4 R5 Scenario get (content_C3) CR4R3C3 H2 ConReq Packet CIDNext HopCostExp. Time C1R3423 C2H3127 C3H3127 Content Lookup Table (CLT) CIDReqHostPrev. HopExp. Time C3H2R334 Reverse Route Table

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