Querying Peers for Required Tracing out Other Peers Content Discovering peers in P2P with discovery and lookup The user initiates the request for content Server provides a list of services as well as a list of peers Any application can make a request fo o notify their presence to the content to a peer once a peer ha traced and located Only a peer can provide the content Discovering peers in P2P with discovery, lookup, and This model traces out peers in response to a request much A peer might not entertain the query like the ot user presents or might not have the y the The dependency on the server is therefore very high Querying Peers for Required Querying Peers for Required Content Content Querying peers for content in pure P2P-based model Querying peers for content in P2P with discovery A peer passes its request for content to another peer p server-based mo If the host peer contains the required information, it not only maintains a list of registered is model provides an interchangeability of role of peers The requesting peer passes its query to the server The searching path of a peer seeking content is thereby Querying seers for sentent in P2P with simple to provide the list of logged-in The role of the server is the most significant The server not only processes the request but also itself gud sting peer has to contact each peer in the listby This method protects information from invasion Processing time is large Sharing Contents with other . Sharing Contents with other Peers Peers Sharing resources with peers in pure P2P-based Sharing resources n P2P with discovery e setthat has the requested information that he requested content Sharing resources with peers in P2P with discovery The returns the list of all connected peers d model this rist ort uired ponftenhes pee dividually This P2P model is almost like the C/s computing erver connect theg peer locates the content required,the the rerwersting peer downloads the required content from The server processes the request, procures the result Both uploading and downloading cap 66 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 31 Tracing out Other Peers „ Discovering peers in P2P with discovery and lookup server-based model „ Server provides a list of services as well as a list of peers „ All users are required to notify their presence to the server while they log in „ The server not only discovers other peers but also returns vital information regarding all logged in peers „ Reduces time consumption „ Discovering peers in P2P with discovery, lookup, and content server-based model „ This model traces out peers in response to a request much like the others „ The server maintains all the vital information and also furnishes the content to requesting peers „ Each peer is registered with the server „ The dependency on the server is therefore very high 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 32 Querying Peers for Required Content „ The user initiates the request for content „ Any application can make a request for content to a peer once a peer has been traced and located „ Only a peer can provide the content required „ A peer might not entertain the query the user presents or might not have the information the user seeks 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 33 Querying Peers for Required Content „ Querying peers for content in pure P2P-based model „ A peer passes its request for content to another peer (host peer) „ If the host peer contains the required information, it satisfies the query „ This model provides an interchangeability of role of peers (client or server) „ Querying peers for content in P2P with simple discovery server-based model „ This model uses a server to provide the list of logged-in peers to a requesting peer „ A requesting peer always gets a large number of peers of interest so it can communicate with them „ The requesting peer has to contact each peer in the list by itself and individually „ Processing time is large 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 34 Querying Peers for Required Content „ Querying peers for content in P2P with discovery and lookup server-based model „ The server not only maintains a list of registered users, but also process queries for the content „ The requesting peer passes its query to the server „ The searching path of a peer seeking content is thereby shortened „ Querying peers for content in P2P with discovery, lookup, and content server-based model „ The role of the server is the most significant „ The server not only processes the request but also procures the result and returns it back „ This method protects information from invasion 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 35 Sharing Contents with other Peers „ Sharing resources with peers in pure P2P-based model „ A peer sends a request for content to another peer „ Peer is the service provider which has shared resources „ It is the peer that has the requested information that opens the connection „ Sharing resources with peers in P2P with simple discovery server-based model „ A peer sends a request for content to the server „ The server returns the list of all connected peers „ The requesting peer approaches peers individually from this list for required content „ Once the requesting peer locates the content required, the server connect them „ The requesting peer downloads the required content from the network „ Uploading content cannot occur in this model 哈工大计算机学院 李全龙 Network Application Development P2P Application Development 36 Sharing Contents with other Peers „ Sharing resources with peers in P2P with discovery and lookup server-based model „ The server doesn’t just furnish the list of peers „ The server carries out the search „ The requesting peer downloads the requested content from the network stream „ Uploading is also possible with this method „ Sharing resources with peers in P2P with discovery, lookup, and content server-based model „ This P2P model is almost like the C/S computing architecture „ All information is housed in the server „ The server processes the request, procures the result, and returns back „ Both uploading and downloading capable