Distributed download v What is distributed download Peer

Distributed download v What is distributed download? Peer #1 100% File Peer #2 50% File Peer #3 75% File Peer #4 30% File Peer #1 100% File Request Peer #2 50% File 100% File Peer #3 75% File Peer #4 30% File Request Peer 0% File in the JXTA P 2 P Network

Distributed download v What is distributed download? 구현 예: Emule v v Request Peer: Yellow->받은 부분, Blue->요구하는 부분 Source Peer: Blue->존재하는 부분, White->없는 부분

Distributed download v The scenario of distributed download in the JXTA Network 1. 모든 Peer는 Share directory에 있는 File을 Network 상에 공유시키기 위해 File에 대한 Advertisement를 publish한다 (Advertisement 는 Hash된 Content Id와 Network상에서 유일한 Peer Id등으로 구성된 XML Document이다)

Distributed download v The scenario of distributed download in the JXTA Network File Advertisements All Peers

Distributed download v The scenario of distributed download in the JXTA Network 2. Request Peer가 JXTA Network 상에서 File을 Search하여 그 List를 User에게 보여준다

Distributed download v The scenario of distributed download in the JXTA Network Search Query File Advertisement List Request Peer

Distributed download v The scenario of distributed download in the JXTA Network 3. User가 특정 File을 선택하면 동일한 Content Id를 가진 모든 Peer들에게 특정 부분 을 요구한다

Distributed download v The scenario of distributed download in the JXTA Network Request Specific part of file to their Owners Request Peer

Distributed download v The scenario of distributed download in the JXTA Network 4. 각 Source Peer들은 Request된 part를 File 로 만들어 Request Peer가 download할 수 있게 만들어 준다

Distributed download v The scenario of distributed download in the JXTA Network Make Requested part of file and Publish an advertisement of that file Source Peer

Distributed download v The scenario of distributed download in the JXTA Network 5. Request Peer는 각 Part들을 download하여 원본 파일을 만들어 download를 완료한다

Distributed download v The scenario of distributed download in the JXTA Network Download all parts of file and sum up Source Peer

Distributed download v Split size Split한 size는? Emule: 180 k v Error check File에 대한 Advertisement에는 그 File을 Hash하여 얻은 Content Id가 포함되어 있다. 이 Id와 download된 File의 Hash값을 비교하여 error여부를 판단하여 error시 재전송을 요구 한다.