1) The document discusses research into improving HTTP adaptive video streaming through network assistance from CDNs and SDNs. 2) It poses research questions about how CDNs and SDNs can provide assistance to HAS clients to improve delivery, and whether client assistance to networks could also be beneficial. 3) The state of the art involves standards for networks to provide information to clients, as well as some research on network-assisted HAS using traditional and SDN-enabled network architectures.

1. CDN and SDN Support and Player Interaction for HTTP
Adaptive Video Streaming
ACM MMSys 2021 Doctoral Symposium
September 30th
, 2021
Reza Farahani
reza.farahani@aau.at | https://athena.itec.aau.at/

2. 2
Agenda
● Introduction
● Research Questions
● State of the art
● Publications and future work

3. Introduction
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4. ● Video traffic has become the dominant traffic over the
Internet.
● It is expected to reach more than 82% of all Internet traffic by
2022 [1].
● HTTP adaptive streaming (HAS) has been considered as the
de-facto video delivery technology over the Internet.
Introduction-Video Streaming
4
[1] Cisco. Global - 2021 Forecast Highlights. https://www.cisco.com/c/dam/m/en_us/solutions/service-provider/vni-forecast-highlights/pdf/Global_2021_Forecast_Highlights.pddf

5. ● The adaptation process can be performed with different schemes:
○ Pure client-based:
■ The decision based on the local parameters, e.g.,
● buffer status
● estimated available bandwidth
■ Insufficient information about the network
● It can lead to a suboptimal adaptation decision
○ Network-assisted:
■ The decision is performed via a centralized network component with a global
view of the entire network topology.
■ can be more beneficial for the users’ QoE
● Fundamental paradigms of modern networks, i.e., SDN, NFV, edge computing have
been used in modern network-assisted frameworks
Introduction- Network-assisted video streaming
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6. ● The fundamental paradigm of modern networks to
address the limitations of conventional network architecture
like:
○ Complex Network Devices
○ Management Overhead
○ Limited Scalability
● The control plane (forwarding decision) is decoupled from
the data plane (acts on the forwarding decision)
○ Centralized Network Controller
○ Standard communication Interface (OpenFlow),
○ Programmable Open APIs
● SDN is deployed in a wide range of network types:
○ Enterprise, campus, datacenter, wide-area networks
(Google B4)
Introduction-Software-Defined Networking (SDN)
6

7. Research Questions
7

8. 1. How SDNs/CDNs provide assistance for HAS clients in order to improve media delivery
services?
● Send information provided from SDN controller, CDN servers, or intermediate devices
like Reverse Proxy server to HAS client.
○ Network map
○ Path information
○ Cache occupancy
○ Throughput measurements
○ Throughput predictions
Research Questions
8

9. ● The SDN controller could employ the following
information provided by HAS clients
for caching, dynamic routing policies, etc.
○ User behavior
○ Content popularity
○ Content prefetching
○ Users requests patterns
○ Representation selection hints
● HAS clients can be used in a hybrid Peer-to-Peer
(P2P)/CDN for:
○ low-latency video streaming
○ improve network bandwidth usage
○ enhance CDN performance.
○
Research Questions
9
2. Will assistance by HAS clients for the SDNs/CDNs (and client-network collaboration) work, which
assistance, how?

10. 3. What is the utility of the proposed assistance and collaboration service?
● QoE parameters:
○ Average quality bitrate, Number of quality switches, Rebuffering, etc.
● CDN utilization:
○ Cache hit rates, Bandwidth/Storage consumption, Server load
● QoS parameters:
○ Delay, Throughput, etc
● Network utilization:
○ Backhaul and transit bandwidth
● SDN controller’s load
○ Messages to/from the controller
● Content providers’ costs
○ Bitrate ladder
4. How can the utility be thoroughly evaluated, both in theoretical and synthetic settings
and in practice?
● Simulation, emulation, and testbed experiments
Research Questions
10

11. State of the art
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12. State of the art
12
● The IETF Working Group ALTO (Application-Layer Traffic Optimization) develops standards:
○ Allow applications to obtain network information(network map and the path costs), for
○ Optimizing server/CDN
○ surrogate selection
○ traffic delivery
● Akamai has a product called NetSession Interface:
○ Support peer-assisted delivery
○ Client-CDN cooperation
○ Software should install on the client device
● Network assistance for HAS clients for “traditional” network architectures.[1]
○ Asynchronous network-to-client and network-to-network communication without any delay
● Network assistance for HAS clients, by utilizing SDN capabilities[2]
● Network assistance for HAS clients through the combined SDN and CDN considerations[3]
[1]E. Thomas, M. O. van Deventer, T. Stockhammer, A. C. Begen, J. Famaey, “Enhancing MPEG DASH Performance via Server and Network Assistance,” SMPTE Motion Imaging Journal, vol. 126, issue 1, Jan.-Feb. 2017.
[2]A. Bentaleb, A. C. Begen, S. Harous, R. Zimmermann, “SDNHAS: An SDN-Enabled Architecture to Optimize QoE in HTTP Adaptive Streaming,” in IEEE Transactions on Multimedia, vol. 19, no. 10, pp. 2136-2151, Oct. 2017.
[3]D. Bhat, A. Rizk, M. Zink, R. Steinmetz, “Network Assisted Content Distribution for Adaptive Bitrate Video Streaming,” In Proceedings of the 8th ACM Multimedia Systems Conference (MMSys '17), pp. 62-75, June 2017

13. 13
Publications and ongoing work

14. ES-HAS: An Edge- and SDN-Assisted Framework for
HTTP Adaptive Video Streaming
14
Farahani, R., Tashtarian, F., Erfanian, A., Timmerer, C., Ghanbari, M. and Hellwagner, H., 2021, October. ES-HAS: An Edge- and SDN-Assisted
Framework for HTTP Adaptive Video Streaming,” in ACM NOSSDAV, 2021.(pp. 50-57).

15. CSDN: CDN-Aware QoE Optimization in
SDN-Assisted HTTP Adaptive Video Streaming
15
Farahani, R., Tashtarian, F., Amirpour, H., Timmerer, C., Ghanbari, M. and Hellwagner, H., 2021, October. CSDN: CDN-Aware QoE Optimization in
SDN-Assisted HTTP Adaptive Video Streaming. In 2021 IEEE 46th Conference on Local Computer Networks (LCN) (pp. 525-532).

16. ● Devise Network-assisted systems for HAS clients that uses edge collaboration
technique
● Devise a Hybrid P2P/CDN system to provide low latency live video streaming service
● Deploy a network-assisted HAS system to improve users’ QoE by optimizing the set of
video representations
Ongoing and future Work
All rights reserved. ©2020 16

17. Thank you for your attention
reza.farahani@aau.at | https://athena.itec.aau.at/
All rights reserved. ©2020
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