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CONTENT
1
4
3
2
Problem & Challenge
Research Scenario & Result
Conclusion
Reference
2
Problem & Challenge
Summary:
MCU-based solution + limited bandwidth→ bottleneck with large traffic
→ high end2end delay → QoE ↓
What is
the
problem?
QoS has not been sufficient enough to examine the specific
application with current diverse networks, especially ones with limited
resources[1]
Conventional application for multi-party access, MCU (multipoint
control unit), degrades the QoE with high end2end delay and heavy
memory burden at the MCU server[3]
Limitation on scalability live video on-demand: bottleneck happens
under fixed bandwidth condition when large traffic flux in[2]
3
MCU-based solution for multi-party access system
( sender-driven)[3]
Problem scenario
BOOM！
4
Problem & Challenge
Why so
important?
To adapt to QoE demands (e.g. video quality / short waiting time)
instead of QoS, providing good application quality to users[1]
To make high quality video delivery to maximize system-wide user
QoE under current proliferating high-speed network access
environment[3]
Even the network bandwidth of resource is sufficient enough, the
internet core itself cannot be burdened with such quantity of
streams, which would generate the traffic congestion[2]
Summary:
Need to streamline the network management, the QoE ↑ is a must!
5
QoS VS QoE
human
expectations
Feelings
Perceptions
Satisfaction
QoEQoS
Packet Classification
Isolation: Scheduling & Policing
High Resource Utilization
Call Admission
Summary: (in terms of scope)
QoS: network
QoE: end-user (psychologically inclined)
6
What is SDN?
Software-Defined Networking with 3 layers:
application plane/network control plane/data plane
Summary:
SDN can leverage the augment information to facilitate network management to improve the user QoE
It can influence one or multiple paths in the network by interacting with
control applications and routing devices in the network[2]
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Application-Aware SDN architecture[1]
What is SDN?
Northbound API (Application
Programmable Interface)
Enable info. exchange
Southbound API
As the controller, adapt to network
according to operator’s requirement
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Control and data paths of proposed SDN-
enabled multicast solution
for multi-party video conferencing systems[3]
What is SDN?
rerouting rate allocation[3]
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objective
Main Research Points & Result
1
• Application-Aware SDN testbed emulates a path selection scenario for an access
network provider.
• Use as few lines as possible should be rented as long as the QoE of the user does not
suffer.
• Use YoMo as a TCP-flow identifier to track the buffered & current playtime when
Youtube video playing.
Application-Aware SDN Testbed Setup [1]10
Problem
formula-
tion
Main Research Points & Result
1
- Reference: Youtube traffic to single client, the controller choose one of five links at random to
transfer the flow.
- Reference with interfering traffic: 2 additional connections to access/provider switch.
- Round-Robin Path Selection: the controller use more than one links.
- Bandwidth-Based Path Selection: bandwidth real-time check; If there is a link with free
capacity available, the controller will then redirect the largest flow in terms of bandwidth
consumption from a loaded link to a free one.
- Deep Packet Inspection: The DPI flow detection. If a particular flow is a YouTube video, the
controller will redirect the flow to another less congested link.
- Application-Aware Path Selection: leverage YoMo info (buffer level) as a controller input;
When it gets below a certain threshold, the application station informs the controller that an
action is required for a particular flow in order to maintain the QoE for the user.
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result
Main Research Points & Result
1
- PRE-BUFFERED PLAYTIME AS MEASUREMENT.
- Reference: reached 55s within first 10s without further data and maintain at stable level.
- Reference with interfering traffic: bandwidth reduced, buffer level dropped and stalled, then
the Youtube player degrades the resolution to meet a smooth stream.
- Round-Robin Path Selection: the playtime decreases but not emptied with uneven
distribution (the controller assign all links but not tell the capacity of each of them).
- Bandwidth-Based Path Selection: still uneven distribution, but with usage of maximum
bandwidth flow which performs better than previous one.
- Deep Packet Inspection: Youtube flow identification and prioritization with stable pre-
buffered playtime but suffered reduced overall usage of available bandwidth usage. (only 2
used)
- Application-Aware Path Selection: redirect Youtube traffic to less load link as controller
detect the threshold playtime, all 5 five links are fully loaded.12
result
Main Research Points & Result
1
- RESOURCE COMSUMPTION EFFICIENCY ρ as another measurement. .
Method ρ
Round-Robin Path
Selection
≈1
Bandwidth-Based Path
Selection
≈1
Deep Packet Inspection ≈0.85
Application-Aware Path
Selection
≈1
13
objective
Main Research Points & Result
2
• Application-Aware SDN testbed emulates a path selection scenario for an access
network provider.
• To support live video streaming of educational content such as lectures and seminars
among university campuses
• Provide an long-running on-line educational video service among nationwide campuses
using GENI’s network infrastructure.
Service architecture overview [2] 14
• GENI: Global
Environment of
Network Innovation.
Problem
formula-
tion
Main Research Points & Result
2
- End-to-End video uploading (UDP) & downloading (TCP)
- RTST (Real Time Streaming Protocol) video streaming -> IP camera -> VLC (IP address
transmission) -> GC gateway controller-> HTTP server;
- VLC request -> GC gateway controller -> appropriate server -> back to GC ->client receive.
- OpenFlow forwarding and path control- Inside mechanism to control the up/down loading path (short/long path)
GENI testbed[2] 15
result
Main Research Points & Result
3
• Evaluation: lower-bounded channel bandwidth requirement of the service/video resolution
• 1080p video transmission under 300Mbps link bandwidth with 5s delay between producer &
consumer.
• Basic bandwidth 3Mbps required. No much bandwidth consumption in service with potentially
scalable space to handle a lot of users.
• Resolution degrades to 800 * 450 under 1Mbps but with freezing & distortion;
• 176 * 144 guarantees good quality on 1Mbps link.
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objective
Main Research Points & Result
3
• To utilize SDN-enabled multicast for multi-party video conferencing services.
Application-Aware SDN Testbed Setup [1]17
Problem
formula-
tion
Main Research Points & Result
3
- MTCP problem: SDN-enable Multicast Tree Construction & Packing Problem
- Combining algorithms:
- 1. H_MCOP (Heuristic Multi-Constrained Optimal Path)
- to find a minimum cost path from a source node to a destination node while at the same time
satisfying K QoS constraints.
- (Bounded Shortest Multicast Algorithm)
- 2. BSMA to construct minimum-cost multicast tree with delay constraints
- 11 nodes and random network topologies
- Examine the average video rate & delay as function of node number & source user number
considering dense-graph & sparse graph (different edges will generate in random topology)
Video Watching relationship[3] 18
result
Main Research Points & Result
3
• Fix topology:
• MCU-based degrades network utility with higher delay than SDN-enable solution
• Random topology:
• The average video rate increases, delay decreases as node number increases.
• The average video rate decreases, delay decreases as user number increases.
• SDN-enabled multicast has higher average multicast rate than MCU-based one, but also a
little bit higher delay than MUC-based, since the trade off between maximizing video rate at
the cost of delay consumption.
• Dense graph performs greater than Sparse graph since more diversed links with higher
efficiency.
19
Conclusion & Improvement
Users can benefit profoundly from SDN network control for
Youtube streaming - limited applicability with OpenFlow
reactive flow setup to smaller networks as experiment
scenario![1]
The video streaming experiment works well on the SDN-Assisted GC
service prototype architecture. The live video is successfully uploaded to the
gateway and to the video server. The download video quality is stable and
reliable - multiple paths implementation need.[2]
SDN-enable multicast solution out-rate MCU-based one[3]
Summary:
SDN-based solution is much more appealing and feasible considering improving QoE!
20
[1] M. Jarschel, F. Wamser, T. Hohn, T. Zinner, P. Tran-Gia, “Sdn-based application-aware
networking on the example of youtube video streaming,” in the Second European Workshop
on Software Defined Networks, 2013.
[2] Q. Wang; K. Xu; R. Izard; B. Kribbs; J. Porter; K. C. Wang; A. Prakash; P. Ramanathan,
“GENI Cinema: An SDN-Assisted Scalable Live Video Streaming Service,” Network
Protocols (ICNP), IEEE 22nd International Conference, Pages: 529 - 532, 2014.
[3] M. Jarschel; F. Wamser; T. Hohn; T. Zinner; P. Tran-Gia, “GENI Cinema: An SDN-
Assisted Scalable Live Video Streaming Service,” Software Defined Networks (EWSDN),
Second European Workshop, Pages: 87 - 92, 2013.
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THANKS
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