Network Working Group H. Xue Internet-Draft Tsinghua University Intended status: Standards Track D. Wang Expires: September 6, 2012 Huawei March 5, 2012 DECADE Use Cases draft-xue-decade-usecase-00 Abstract The objective of DECADE is to provide storage access to Content Distribution Applications to improve their efficiency and reduce load on the network infrastructure. In this document, we outline several potential use cases (not technical solutions) for DECADE. These use cases may provide motivations for DECADE. Interactions within DECADE and between DECADE Servers and DECADE Clients are described at an abstract level so as to not constrain future protocol development. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on September 6, 2012. Copyright Notice Copyright (c) 2012 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 Xue & Wang Expires September 6, 2012 [Page 1] Internet-Draft Usecase March 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminologies . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Example Use Cases . . . . . . . . . . . . . . . . . . . . . . 4 3.1. P2P File Sharing . . . . . . . . . . . . . . . . . . . . . 4 3.2. End User Video Conference . . . . . . . . . . . . . . . . 5 3.3. Offline P2P live streaming . . . . . . . . . . . . . . . . 6 3.4. Social Networks . . . . . . . . . . . . . . . . . . . . . 7 4. Integration of DECADE and CDNI . . . . . . . . . . . . . . . . 9 4.1. Consideration of Integrating DECADE and CDNI . . . . . . . 9 4.2. An Example Use Case . . . . . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 7.1. Normative Reference . . . . . . . . . . . . . . . . . . . 12 7.2. Informative Reference . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 12 Xue & Wang Expires September 6, 2012 [Page 2] Internet-Draft Usecase March 2012 1. Introduction DECADE provides standard in-network storage for content distribution applications. Specifically, with access to in-network storage, content distribution applications can improve their efficiency and reduce load on the network infrastructure. For example, instead of always uploading data objects directly from a source/owner client to a requesting client, the source/owner client can upload from in- network storage, saving uplink bandwidth. This document describes several use cases to motivate DECADE. These use cases may provide motivations for the design and deployment of DECADE. Also, a use case indicating our consideration of integrating DECADE with CDNI is presented in this draft, in order to explore potential benifits of combining them as well as possible further work directions. 2. Terminologies The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "WOULD", "COULD", "CANNOT", "MIGHT", and "MAY"in this document are to be interpreted as described in [RFC2119]. We use the following terms that are defined [draft-ietf-decade-arch- 03]. Provider based in-network storage: A service inside a network that provides storage and bandwidth to network applications. In-network storage may reduce upload/transit/backbone traffic and improve network application performance. DECADE Server: A DECADE Server stores data from Application End- Points, and provides control and access of those data to Application End-Points. Note that a DECADE Server is not necessarily a single physical machine; it could also be implemented as a cluster of machines. DECADE Client: A DECADE Client stores and retrieves data at DECADE Servers. Application End-Point: An Application End-Point is an instance of a Content Distribution Application that makes use of DECADE Server(s). A particular Application End-Point may be a DECADE Content Provider, a DECADE Content Consumer, or both. For example, an Application End- Point may be an instance of a video streaming client, or it may be the source providing the video to a set of clients. Xue & Wang Expires September 6, 2012 [Page 3] Internet-Draft Usecase March 2012 3. Example Use Cases 3.1. P2P File Sharing Related Applications: There are many P2P file sharing applications, e.g., BitTorrent, Shareaza, Ares. The most widely used is BitTorrent. Original setting: In BiTorrent without DECADE, a client uploads to its peers using its last mile. This consumes expensive last-mile uplink bandwidth. BiTorrent with DECADE: In the new setting, a client first uploads to a DECADE Server, who can then serve other clients. Figure 1 shows an example. In this example, Client B first uploads shared files to DECADE Server B, then Client A and Client C can get the file by their DECADE Servers. +-------------------+ +-------------------+ | | | | | DECADE Server A | | DECADE Server C | | | | | +-------------------+ +-------------------+ | ^ ^ | | \ / | | \ / | | \ / | | \ / | | \ / | | \ / | | +-------------------+ | | | | | | | DECADE Server B | | | | | | | +-------------------+ | | ^ | | | | V | V +----------+ +----------+ +----------+ | | | | | | | Client A | | Client B | | Client C | | | | | | | +----------+ +----------+ +----------+ Figure 1 Benefits: in Original setting, Client B may need send content to both Client A and Client C, while in DECADE Client B only need send the Xue & Wang Expires September 6, 2012 [Page 4] Internet-Draft Usecase March 2012 shared file to its DECADE server for one time. This saves last mile uplink bandwidth, which is expensive. 3.2. End User Video Conference Related Applications: There are multiple widely video conference applications, including Skype, Webex. The end users using the conference applications can be either desktop based or mobile devices. Video Conference without DECADE: As it is shown if figure 2, Client A and Client C send the voice and video to Client B, Client B mix its own packets with those send from Client A and Client C, then send the mixed packets to them. +----------+ A+C +----------+ A+B +----------+ | | <------ | | ------> | | | Client A | | Client B | | Client C | | | ------> | | <------ | | +----------+ B +----------+ C +----------+ Figure 2 Video Conference with DECADE: Figure 3 shows a example of video conference using DECADE. In this example, each client upload its video and audio data for one time, and DECACE Servers will mixed the packets and send to each users. Xue & Wang Expires September 6, 2012 [Page 5] Internet-Draft Usecase March 2012 +----------+ | | | Client A | | | +----------+ ^ | B+C | | A | | | V +-------------------+ | | | DECADE Server A | | | +-------------------+ ^ ^ B / \ C / \ / A A \ V V +-------------------+ +-------------------+ | | C | | | DECADE Server B | <--------> | DECADE Server C | | | B | | +-------------------+ +-------------------+ ^ | ^ | B | | A+C C | | A+B | V | V +----------+ +----------+ | | | | | Client B | | Client C | | | | | +----------+ +----------+ Figure 3 Benefits: in Original setting, the mixer (Client B in figure 2) need upload twice, while in Video Conference with DECADE each user only need upload its video and audio for one time. This saves last mile uplink bandwidth. 3.3. Offline P2P live streaming Related Applications: There are many P2P live streaming applications, e.g., PPLive, PPStream. Original setting: In P2P live streaming without DECADE, clients may get a bad user experience when they watch the streaming after broadcasting at a later time, Since there will be not enough Xue & Wang Expires September 6, 2012 [Page 6] Internet-Draft Usecase March 2012 audiences to watch it after living broadcast. P2P live streaming with DECADE: By using DECADE, a client can watch a live streaming at a later time, and still have a good video quality. Figure 4 shows an example. In this example, Client B is broadcasting a live streaming. Client C is offline and wants to watch this streaming at a later time. DECADE Server C will hold the living streaming data for Client C. After Client C once is online, it can get the streaming directly for its DCEADE Server C. +-------------------+ +-------------------+ | | <---------------- | | | DECADE Server A | | DECADE Server C | | | ----------------> | | +-------------------+ +-------------------+ | ^ ^ | | \ / . | \ / | | \ / . | \ / | | \ / . | \ / | | +-------------------+ . | | | | | | DECADE Server B | . | | | | | +-------------------+ . | ^ | | | . V | V +----------+ +----------+ +----------+ | | | | | | | Client A | | Client B | | Client C | | | | | | | +----------+ +----------+ +----------+ Figure 4 Benefits: in Original setting, clients missed living streaming broadcast, may get a bad video quality when they watch it at a latter time. While in DECADE the video quality is also good since Client C download it directly from its DECADE Server. Also, DECADE can help to save last mile uplink bandwidth in this use case. 3.4. Social Networks Related Applications: Facebook, Renren. Xue & Wang Expires September 6, 2012 [Page 7] Internet-Draft Usecase March 2012 Social Networks without DECADE: As it is shown in figure 5, Client A post a message to Facebook Server, then the Server update this message to Client B, Client C and Client D. There are data transmission both in inter-domain and intra-domain. +------------------------------------------------------+ | +----------+ ISP | | | | | | +----------| Client A | | | | | | | | | +----------+ | | | | | | | | | | | +--------------+ +----------+ | | | | | | | | +-------------------->| Client B | | | | | | | | | | +----------+ +----------+ | | | | | | | | | | | | | | | +----------+ | | | | | | | | | | | +--------->| Client C | | | | | | | | | | | +----------+ | +--------|---|-----------------------------------------+ | | | | V | +---------+ | | +----------+ | Facebook| | | | Server |--------------->| Client D | | | | | +---------+ +----------+ Figure 5 Social Networks using DECADE: Figure 6 shows Facebook using DECADE. Client A post the message to its DECADE Server X, then DECADE Server X will update these clients in intra-domain, simultaneously update Facebook Server. Xue & Wang Expires September 6, 2012 [Page 8] Internet-Draft Usecase March 2012 +------------------------------------------------------+ | +----------+ ISP | | | | | | +----------| Client A | | | | | | | | | +----------+ | | | | | | | | +---------+ | | | | |<----+ +----------+ | | | DECADE | | | | | | Server |--------------->| Client B | | | | X | | | | | | |-----+ +----------+ | | +---------+ | | | | | | | | | +----------+ | | | | | | | | | +--------->| Client C | | | | | | | | | +----------+ | +------------|-----------------------------------------+ | | V +---------+ | | +----------+ | Facebook| | | | Server |--------------->| Client D | | | | | +---------+ +----------+ Figure 6 Benefits: Cut down data transmission in inter-domain. And also DECADE Server will help to reduce Facebook Server load. 4. Integration of DECADE and CDNI 4.1. Consideration of Integrating DECADE and CDNI As mentioned above, DECADE provides standard in-network storage for content distribution applications, which can reduce load on internet infrastructure as well as improve the efficiency of these applications. CDNI is aimded at providing uniformed interfaces over which two or more CDNs communicate with each other in order to achieve the delivery of content to User Agents by Surrogates in one Xue & Wang Expires September 6, 2012 [Page 9] Internet-Draft Usecase March 2012 CDN (the downstream CDN) on behalf of another CDN (the upstream CDN)[I-D.ietf-cdni-problem-statement-03]. The work of DECADE and CDNI are complementary to each other in some respects. DECADE architecture and mechanism can be used for data exchange between different CDNs, while CDNI supports negotiation between them, in which upstream CDN could indicate the downstream CDN to acquire content from certain in-network storages (DECADE Servers). 4.2. An Example Use Case Taking Multi-player Online Game application as an example, Figure 8 shows the idea of integrating DECADE and CDNI. In this example, both Client A and Client B belong to CDN-1, while Client C is connected to CDN-2. Each Client store its own game-related data to its own DECADE Server and also retrieve other Clients' data from it. The communication between CDN-1 and CDN-2 is conducted by CDNI. Through CDNI, the upstream CDN indicates where its downstream CDN could retrieve data it wants. Xue & Wang Expires September 6, 2012 [Page 10] Internet-Draft Usecase March 2012 +-------------------+ +-------------------+ | | | | | DECADE Server A | | DECADE Server C | | | | | +-------------------+ +-------------------+ ^ ^ ^ ^ | \ / | | \ / | | \ / | | \ / | | \ / | | v v | | +-------------------+ | | | | | | | DECADE Server B | | | | | | | +-------------------+ | | ^ | | | | | | | v v v +----------+ +----------+ +----------+ | | | | | | | Client A | | Client B | | Client C | | | | | | | +----------+ +----------+ +----------+ | | | | | | | | | | | | -------------------- | | | | | | | +----------+ +----------+ | | CDNI | | | CDN-1 |<------------------>| CDN-2 | | | | | +----------+ +----------+ Figure 8 Benefits: The integration of DECADE and CDNI may result in improved quality of experience for end users, as well as reduced last-mile uplink bandwidth. The benefits may not be obvious when there are only few content delivery between two different CDNs, but it may have significant benefits in certain situations. Xue & Wang Expires September 6, 2012 [Page 11] Internet-Draft Usecase March 2012 TBA. 5. Security Considerations This draft does not introduce any security considerations beyond those of these use cases. 6. IANA Considerations This document has no actions for IANA. 7. References 7.1. Normative Reference [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", March 1997. 7.2. Informative Reference [I-D.ietf-decade-problem-statement] Song, H., Zong, N., Yang, Y., and R. Alimi, "DECoupled Application Data Enroute (DECADE) Problem Statement", March 2011. [I-D.ietf-decade-arch] Alimi, R., Yang, Y., Kutscher, D., and H. Liu, "DECADE Architecture", July 2011. [I-D.ietf-cdni-problem-statement] Ben, N., Francois, F., and B. Nabil , "Content Distribution Network Interconnection (CDNI) Problem Statement", Jan 2012. Xue & Wang Expires September 6, 2012 [Page 12] Internet-Draft Usecase March 2012 Authors' Addresses Xue Haiwei Tsinghua University Tsinghua University Beijing, 100000 P.R.China Phone: Fax: Email: heavyxue@gmail.com Wang Danhua Huawei No. 101 Software Avenue Nanjing, Jiangsu Province 210001 P.R.China Phone: +86-25-56624734 Fax: +86-25-56624702 Email: wangdanhua@huawei.com Xue & Wang Expires September 6, 2012 [Page 13]