Peer-to-Peer Streaming Peer Protocol (PPSPP)
RFC 7574
Internet Engineering Task Force (IETF) A. Bakker
Request for Comments: 7574 Vrije Universiteit Amsterdam
Category: Standards Track R. Petrocco
ISSN: 2070-1721 V. Grishchenko
Technische Universiteit Delft
July 2015
Peer-to-Peer Streaming Peer Protocol (PPSPP)
Abstract
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 prerecorded (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
Low Extra Delay Background Transport (LEDBAT) for congestion control.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7574.
Bakker, et al. Standards Track [Page 1]
RFC 7574 PPSPP July 2015
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction ....................................................5
1.1. Purpose ....................................................5
1.2. Requirements Language ......................................6
1.3. Terminology ................................................6
2. Overall Operation ...............................................9
2.1. Example: Joining a Swarm ...................................9
2.2. Example: Exchanging Chunks ................................10
2.3. Example: Leaving a Swarm ..................................10
3. Messages .......................................................11
3.1. HANDSHAKE .................................................11
3.1.1. Handshake Procedure ................................12
3.2. HAVE ......................................................14
3.3. DATA ......................................................15
3.4. ACK .......................................................15
3.5. INTEGRITY .................................................15
3.6. SIGNED_INTEGRITY ..........................................16
3.7. REQUEST ...................................................16
3.8. CANCEL ....................................................16
3.9. CHOKE and UNCHOKE .........................................17
3.10. Peer Address Exchange ....................................17
3.10.1. PEX_REQ and PEX_RES Messages ......................17
3.11. Channels .................................................19
3.12. Keep Alive Signaling .....................................20
4. Chunk Addressing Schemes .......................................21
4.1. Start-End Ranges ..........................................21
4.1.1. Chunk Ranges .......................................21
Show full document text