Emmanuel Weber - Blue Jeans 10/15/2014

1. Emmanuel Weber
10/15/2014
Optimizing Real Time
Interactive Video Delivery from
the Cloud

2. Highlights
 Cloud based video conferencing solutions are
some of the latest novelties in bidirectional real-time
video.
 Because of the unprecedented scale of those
solutions and new type of deployments, there is an
opportunity to revisit old problems and provide
some new answers to them. This is particularly
true in the area of real-time video delivery.

3. Problems affecting video delivery
Traditional problems:
 Bandwidth
 Loss
 Jitter
 Out of order packets
 Duplicate packets
 Congestion
Problems specific to the “last mile”:
 Congested Wifi
 Restricted firewall

4. Brief history of video deployments
Roughly three phases:
 Private controlled network
 Hosted
 Cloud + over the top (OTT) over Internet

5. Private / Controlled network
 The network is fully controlled by enterprise IT
 Can implement QoS techniques and dimension the
network in such a way that most problems affecting
video quality are solved
 Doesn’t work well for interactions with parties outside of
the controlled network (difficult to setup call and overall
quality concerns).

6. Private / Controlled network
Private
Deployment

7. Hosted
 Same software used in private deployment is used in a
remote location often accessed over the Internet.
 Software is maintained by a third party.
 Solution usually not designed to handle Internet traffic or
difficult network.
 Somewhat worst of both worlds in term of video delivery.
Lose benefit of controlled environment and external party
does not necessarily see improvements in terms of video
quality.

8. Hosted Deployment
Data
Center

9. Traditional cloud base solution
 Dedicated software designed for Internet traffic.
 Solution is distributed geographically in multiple data
centers to get closer to endpoints.
 Traffic can be routed between data centers to optimize
network path between endpoints.

10. Traditional Cloud Base solution
Data
Center
Data
Center

11. Cloud based / CDN type deployment
 It is possible to improve the video delivery one step further by
breaking down the problem once more.
 By pushing some of the functionality as close as possible to the
endpoints, overall video performance can be greatly improved.
 This can be accomplished by a “transparent relay (TR)” that
funnels RTP/RTCP streams.
 TR ideally should be located as close as possible to the
endpoint. This is very similar in concept to traditional CDN
solution for video streaming.

12. Cloud based / CDN type deployment
TR
TR
TR
TR
TR
TR
TR
TR
TR
Data
Center
Data
Center

13. Transparent Relay (TR)
 MANE type device
 As close as possible to the endpoint
 Many deployed across the globe. The shorter the round-trip
time between the TR and the endpoint, the better.
 Provides several benefits:
• Error resilience schemes
• Better bandwidth predictor (early congestion detection)
• Better network control (Ex: avoid overloaded peering point)
• Network analytics

14. Transparent Relay
Packet Queue
RTX FEC
SRTP
Bandwidth
Estimator
Control
Endpoint RTP/RTCP Cloud
RTP/RTCP
Control
• TR is mostly concerned with RTP/RTCP traffic. No control connection between the
endpoint and the TR.
• Control connection between the TR and rest of the cloud software. Used to receive
configuration such as payload information, encryption keys etc.
• Some lightweight processing (FEC, SRTP)
• Network path between TR and rest of the cloud infrastructure is managed by the cloud
operator.

15. Error resilience schemes
TR can implement several error resilience schemes
 Retransmission (RTX)
• Particularly effective due to the low delay between the TR and the
endpoint.
 Forward error correction (FEC)
• Can be generated relatively cheaply in terms of computational power
at the edge of the network to protect the stream.
 Stream shaping
• TR can shape the video stream when scalable media is used.

16. Bandwidth predictor
 By being closer to the endpoint, there is less network
uncertainty.
 Bandwidth estimation using indirect methods like delay
detection are more accurate and can react quicker to any
congestion.
 Bandwidth probing is also more reliable.

17. Better network control
 Cloud provider can manage the network infrastructure
dynamically with fewer unknown third parties.
 In the extreme case, the TR is on the customer premise.
This can provide almost the same reliability as private
network deployment.
 Connections that uses TCP or HTTPS to go through a
restricted firewall are terminated earlier greatly improving
TCP performance.

18. Network Analytics
 The TR can provide analytics on the quality of the network.
 By reacting to those analytics, the cloud operator can adapt
its network infrastructure and improve the overall delivery of
the video
• Chose alternate provider or network path to serve some areas
• Route calls to a different geography
• …

19. Conclusion
 Using existing technologies, rethinking the video
infrastructure in a cloud based context makes it possible to
deliver real-time bidirectional video very efficiently.
 Cloud based delivery is a relatively new area. There is
plenty of room for improvement.

20. Emmanuel Weber
eweber@bluejeans.com
Thank You