Internet DRAFT - draft-xue-decade-usecase
draft-xue-decade-usecase
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
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This Internet-Draft will expire on September 6, 2012.
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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
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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.
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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
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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.
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+----------+
| |
| 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
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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.
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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.
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+------------------------------------------------------+
| +----------+ 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
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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.
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+-------------------+ +-------------------+
| | | |
| 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.
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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.
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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
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