Technical Summary
The Peer-to-Peer Streaming Peer Protocol (PPSPP) is a protocol for
disseminating the same content to a group of interested parties in a
streaming fashion. PPSPP supports streaming of both pre-recorded
(on-demand) and live audio/video content. It is based on the peer-
to-peer paradigm, where clients consuming the content are put on
equal footing with the servers initially providing the content, to
create a system where everyone can potentially provide upload
bandwidth. It has been designed to provide short time-till-playback
for the end user, and to prevent disruption of the streams by
malicious peers. PPSPP has also been designed to be flexible and
extensible. It can use different mechanisms to optimize peer
uploading, prevent freeriding, and work with different peer discovery
schemes (centralized trackers or Distributed Hash Tables). It
supports multiple methods for content integrity protection and chunk
addressing. Designed as a generic protocol that can run on top of
various transport protocols, it currently runs on top of UDP using
LEDBAT for congestion control.
Working Group Summary
There were several issues raised during WGLC; however, none were
particularly rough and authors came up with the text that resolves these
issues thus consensus was achieved in all cases. After that, some
technical comments were made during the AD review and all were
addressed and accepted with consensus.
Document Quality
This draft has some implementations and evaluations in the lab. It is
expected that with the approval of this document the number of
implementations will increase. During the WGLC, this draft has been deep
reviewed by Riccardo Bernardini and Yunfei Zhang. The issues of protocol
versioning and guideline absence on when to declare a peer dead are
addressed. The AD found some high level issues which have been already
solved. One issue is that PPSPP as a Standards Track protocol cannot
normatively rely on LEDBAT which is an Experimental congestion control
mechanism. The problem is solved by having measurements and
deployment results that show the widespread use of LEDBAT in current
P2P systems and towards a DOWNREF procedure.
Personnel
Document Shepherd: Rachel Huang
Responsible AD: Martin Stiemerling