List of Requirements

Specification in general / baseline functionality

  • independent of actual streaming mechanisms
  • describe streams
  • establish streams
  • support alternative streaming technologies with custom stream establish mechanism
  • a set of streaming mechanisms as attachment to specification

Stream description

  • it should be possible to describe 1-to-1 and 1-to-many streams
  • it should be possible to describe a "back-channel" stream (for stream "answers" by the client)
  • it may be useful to describe a streams size, if available (e.g., large file transfer, printer job, non-live video)

Stream subscription

Two mechanisms for stream subscription are conceivable

  • Without handshake: Some streaming protocols do not need subscription information (connectionless, e.g., UDP-broadcast-based) or include their own subscription methods. In these cases, WS-Streaming is used for stream description only.
    • simple
  • With handshake: For streaming protocols without or with insufficient integrated subscription methods, WS-Streaming should offer subscription methods.
    • more complex to specify and implement
    • may resemble WS-Eventing verbs
    • should include authentication and key-exchange for encryption (re-use WS-Security?)
    • if subscription is handled by WS-Streaming, there should probably be a method for unsubscribing in WS-Streaming, too.