P2P Streaming Protocol (PPSP) Requirements draft-zong-ppsp-reqs-03

Requirements Overview Basic requirements to PPSP nodes (tracker and peer) and the content resource. General requirements to the message format and process flow of PPSP tracker protocol and PPSP peer protocol. Error handling and overload protection requirements. Security requirements.

Changes in -03 Defined some additional terms Defined some additional terms  Peer list A list of peer ID which are in a same swarm maintained by the PPSP tracker A list of peer ID which are in a same swarm maintained by the PPSP tracker  Swarm ID An identifier of certain swarm. It is used to describe a specific resource shared among peers. An identifier of certain swarm. It is used to describe a specific resource shared among peers.  Chunk ID An identifier of certain chunk in a resource which shows the position (e.g. time) of the chunk in the whole content resource (e.g. live streaming). An identifier of certain chunk in a resource which shows the position (e.g. time) of the chunk in the whole content resource (e.g. live streaming).  Buffer Map A map indicating which chunks a peer currently has buffered and can share with other peers. A map indicating which chunks a peer currently has buffered and can share with other peers.

Changes in -03 Add some requirements to PPSP nodes Add some requirements to PPSP nodes  Each peer in PPSP MUST has a unique identifier, i.e. peer ID.  The tracker in PPSP MUST has a public identity that can be discovered and accessed by PPSP peers.

Changes in -03 Add some requirements to PPSP content resource Add some requirements to PPSP content resource  The content in PPSP MUST be identified by swarm ID.  The content resource shared by a swarm in PPSP MUST allow being partitioned into chunks with a standard format (defined by some out-of-band mechanism, e.g. meta data).  The content resources shared in PPSP MUST be classified and identified by different usage types (e.g. live, VoD). (Open Q: out-of-band mechanism?)

Changes in -03 Add some requirements to PPSP tracker protocol Add some requirements to PPSP tracker protocol  The tracker request message MAY include parameter of requested number of downloading peers or preferred downloading bandwidth.  The PPSP tracker MAY generate the peer list with the help of traffic optimization services, e.g. Alto. (Open Q: implementation issue of tracker?)

Changes in -03 Add some requirements to PPSP peer protocol Add some requirements to PPSP peer protocol  The content availability update message MUST be advertised among swarm peers periodically or on- demand. (Open Q: MAY or MUST?)  The peer streaming status update information MAY be advertised among peers.

Changes in -03 Add some requirements to error handling and overload protection Add some requirements to error handling and overload protection  The PPSP tracker protocol and peer protocol MUST use TCP based transport to ensure the reliability during the signaling message transmission. (Open Q: consensus on TCP?)

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