Peer-to-Peer (P2P) applications, including both P2P streaming and P2P file-sharing applications, make up a large fraction of traffic in the Internet today. One way to reduce access network and/or cross-domain bandwidth usage by P2P applications is to introduce storage capabilities in the network between hosts running P2P applications. Allowing P2P applications to store and retrieve data from inside the network can reduce traffic on the last-mile uplink, as well as backbone and transit links.
Existing P2P caches often implement the specific P2P application protocols to operate transparently or act as super peers to provide in-network storage. However, it is challenging for P2P cache vendors to support a variety of evolving protocols. Also, for P2P applications, closed P2P caching systems limit effective utilization of in-network storage. Some P2P protocols may be entirely unsupported by a particular caching system. Additionally, applications may be better-equipped to decide how in-network storage is used to meet their specific requirements (e.g., data placement, access control and resource control). Note that providers of in-network storage may impose their own access control or resource usage policies.
Both of these challenges can be effectively addressed by using open, standard protocols to access in-network storage. P2P applications can store and retrieve content in the in-network storage, as well as control resources (e.g., bandwidth, connections) consumed by peers in a P2P application. As a simple example, a peer can choose to store content in the in-network storage, and direct other peers to retrieve from that location, reducing last-mile link usage. Furthermore, since a P2P client may have multiple peers, it can control resources used by each peer to store and retrieve content. Though there are existing data access protocols (e.g., HTTP, NFS, WebDAV), they might be lacking capabilities for fine-grained access and resource control (e.g., bandwidth and connections) that are essential for today's advanced P2P applications.
The Working Group (WG) will have three primary tasks. First, the WG will identify target applications to appropriately scope the problem and requirements. P2P applications are the primary target, but suitability to other applications with similar requirements may be considered depending on additional complexity required to support such applications.
Second, the WG will identify the requirements to enable target applications to utilize in-network storage. Requirements will include the ability for an application to (1) store, retrieve, and manage data, (2) indicate access control policies for storing and retrieving data suitable to an environment with users across multiple administrative and security domains (e.g., in a P2P environment), and (3) indicate resource control policies for storing and retrieving data.
Third, the WG will develop an architecture within which the DECADE protocol can be specified. This architecture will identify DECADE's relationship to existing IETF protocols and where (if any) new protocol is needed or extensions to existing protocols need to be made. The architecture will not specify a protocol or extension; if development of a new protocol is needed, the WG will seek to recharter for this purpose or might ask an existing WG to work on such extensions.
The WG will focus on the following work items:
- A "problem statement" document. This document provides a description of the problem and common terminology.
- A requirements document. This document lists the requirements for the in-network storage service (e.g., supported operations) and the protocol to support it. The service will include storing, retrieving, and managing data as well as specifying both access control and resource control policies in the in-network storage pertaining to that data.
- A survey document. This document will survey existing related mechanisms and protocols (e.g., HTTP, NFS, and WebDAV), and evaluate their applicability to DECADE.
- An architecture document. This document will identify DECADE's relationship with existing IETF protocols. Existing protocols will be used wherever possible and appropriate to support DECADE's requirements. In particular, data storage, retrieval, and management may be provided by an existing IETF protocols. The WG will not limit itself to a single data transport protocol since different protocols may have varying implementation costs and performance tradeoffs. However, to keep interoperability manageable, a small number of specific, targeted, data transport protocols will be identified and used.
- An document describing the integration of DECADE with existing P2P applications (e.g., integration with BitTorrent).
If new protocol development is deemed necessary, the WG will be rechartered. It is not expected that all work items will be ready for IESG review by that point, but WG consensus must show that documents directing eventual protocol development (Requirements and Architecture document) have stabilized. This permits adjustments to such documents as necessary to maintain consistency as protocol development is done.
The following issues are considered out-of-scope for the WG:
- Specification of policies regarding copyright-protected or illegal content.
- Locating the "best" in-network storage location from which to retrieve content if there are more than one location can provide the same content.
- Developing a new protocol for data transport between P2P applications and in-network storage.
Submit DECADE Integration Examples to IESG as Informational
Working Group Last Call for DECADE Integration Examples
Submit Architecture document to IESG as Informational
Identify need for rechartering
Submit Requirements document to IESG as Informational