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What is the minimum bandwidth requirement to use the Vonage Video API?

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Rama Ganesan
  • Updated

Question

If I want to use the Vonage Video API, what is the minimum bandwidth required for my network?

Applies To

  • Vonage Video API
  • Bandwidth
  • Network Connectivity
  • Video Quality
  • Audio Streams
  • Audio & Video Streams

Answer

We recommend a minimum dedicated 350kb/s down per downloaded stream, as well as 350kb/s up per uploaded stream to maintain a stable video connection.

For various resolutions and quality combinations, the bandwidth requirements are outlined below.

  • Excellent - None or imperceptible impairments in media
  • Acceptable - Some impairments in media, leading to some momentary disruptions

Audio + Video Streams

For the given qualities and resolutions, all the following conditions must met.

Quality Video Resolution @ FPS Video kbps Packet Loss
Excellent  1920x1080 @ 30 > 3500 < 0.5%
Excellent 1280x720 @ 30 > 1000 < 0.5%
Excellent 640x480 @ 30 > 600 < 0.5%
Excellent 352x288 @ 30 > 300 < 0.5%
Excellent 320x240 @ 30 >300 < 0.5%
Acceptable 1280x720 @ 30 > 350 < 3%
Acceptable 640x480 @ 30 > 250 < 3%
Acceptable 352x288 @ 30 > 150 < 3%
Acceptable 320x240 @ 30 > 150 < 3% 


The default publish settings for video are 640x480 pixels @ 30 fps in OpenTok.js and the OpenTok iOS SDK. The default is 352x288 @ 30 fps in the OpenTok Android SDK.

Note: For FHD (1920x1080) resolution it is recommended to have available bandwidth of 3Mbps-5Mbps per FHD stream to maintain acceptable quality.  At the publisher, when simulcast is used, 6Mbps upload bandwidth is required to publish multiple quality layers.

Audio-Only Streams

For the given qualities, the following conditions must met.

Quality Audio kbps Packet Loss

Excellent

 > 30 < 0.5%
Acceptable > 25 < 5%

Additional Information

Video quality dynamically adjusts based on the strength of a user's network connectivity. This is done using feedback messages for bandwidth estimation between Publishers and Subscribers to determine what resolution can be supported by the network conditions. The Publisher will adjust the published video bitrate based on the round trip feedback packets it receives. The faster and more stable a Subscriber's broadband connection is, the better the video quality it will request.

In relayed sessions, the video bandwidth estimation is directly between Publisher and Subscriber.  In routed sessions, the video bandwidth estimation is calculated for each Subscriber and the Publisher feedback is managed by the media router. When the scalable video is used, the media router will choose the best video quality layer for the Subscriber based on the simulcast layers present, the preferred resolution, and the bandwidth available at the Subscriber.

If a Subscriber's bandwidth drops below a certain threshold, or if a Publisher has very little bandwidth to upload video, behavior can be unpredictable. Video may be choppy, audio may have artifacts, and the connection could be dropped.

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