Best Practices to Get Started With Vonage Video

This guide describes some best practices for getting started with the Vonage Video API, covering topics such as configuring your environment, ensuring a good user experience, and security and privacy.

What is the Video API?

Vonage Video uses webRTC for audio-video communications and consists of client libraries for web, iOS, Android, React Native, Windows, and Linux, as well as server SDKs and REST APIs. Key Terms:

  • The Video API platform uses tokens for authorisation, meaning that you don’t have to worry about creating users on the platform; if needed, they can be created by the application.
  • Session: A session is a logical group of connections and streams. Connections within the same session can exchange messages. Think of a session as the “virtual room” where participants can interact with each other. Sessions should not be reused as it makes troubleshooting difficult and your implementation potentially less secure.
  • Connection: is an endpoint that participates in a session and is capable of sending and receiving messages. A connection has a presence, it is either connected and can receive messages, or it’s disconnected.
  • Stream: media stream between two connections. This means that actual bytes containing media are being exchanged. Media can consist of audio only, or audio and video. You can also create screenshare and custom streams.
  • Publisher: clients publishing media streams.
  • Subscriber: clients receiving media streams.

Further information on what the Video API is can be found on the Technical Details page, and a detailed guide on how to get up and running with the Video API can be found in Getting Started.

Project and Server Best Practices

Setting up your environment

When designing a video application, consider having two environments; one for testing and one for production. To test simple items, or to reproduce issues, you can also use our playground, which is linked below:

  1. Create an application for each environment, like development and production.
  2. Playground

Understanding API (and SDK) versioning

For Enterprise environment customers, it is important to note that newly created applications will be using the Standard environment by default. If you need to switch your environment from Standard to Enterprise, you can do so in your application settings.

To ensure your application calls the Enterprise JS SDK, use source = https://video.enterprise.vonage.com/v2/js/opentok.js to ensure you receive long term support on your SDKs.

For more info, visit the Enterprise environment guide.

Best Practice for setting up your account credentials

Keep these guidelines in mind when creating your account credentials:

Application ID and Private Key

  • Vonage Video does not use the account API Key and Secret, but relies on using an Vonage Application.
  • Keep the private key secret by NOT exposing them to public repos.
  • Do NOT save the private key in client libraries/compiled mobile SDKs.
  • Do not make REST API calls from the client applications or mobile applications. This will expose your Private Key and make your account vulnerable. Only the Application ID should be considered public information.

Session ID

  • Always generate a new sessionId for every new session created.
  • Sessions’ quality scores and data are indexed by sessionId. If there are multiple conversations (meetings) per sessionId, it will be difficult to debug using Vonage’s inspector tool, because reused sessionIds tend to report lower aggregate quality scores than the actual call quality experienced by end users.

Tokens

  • Your server that generates tokens must be placed behind a secured/authenticated endpoint.
  • Always generate new tokens for each participant.
  • Do not store or reuse tokens.
  • By default, tokens expire after 24 hours, this is checked at connection time. Adjust the expiration as needed, depending on your use case and application.
  • Add additional information to tokens (using the data parameter), such as usernames or other information to identify participants, but NEVER use personal information.
  • Set roles when applicable, such as moderator, publisher, and subscriber.
  • For more information about tokens, check out the Token Creation Overview.

Understanding Media Router and Media Modes

When you create a session, you specify how clients in the session will send audio-video streams, known as the media mode. There are two options, Relayed Mode or Routed Mode:

Relayed Mode:

This media mode does not use Vonage media servers, but instead attempts to create a direct media connection between the participants. Before deciding whether to use relayed mode or not, be sure to consider the following:

  • Platform features such as archiving (recording), SIP integration, live streaming and experience composer are not needed
  • That the use case is one-to-one and 3-party sessions only
  • Where direct media between participants is preferred
  • End-to-end media encryption is required

Note that media quality will not be managed in relayed mode, given media is exchanged between clients. Therefore, setting the subscriber’s frame rate and/or resolution will not work. For more information about tokens, check out the Scalable Video page.

Routed Mode:

This media mode uses Vonage media servers. Before deciding whether to use routed mode or not, be sure to check the following:

  • That your video sessions will have three or more participants
  • May have a need to archive
  • Needs media quality control (audio fallback and video recovery)
  • May have a need to use SIP interconnect
  • May have a need to use interactive or live streaming broadcast
  • End-to-end encryption requires add-on subscription and is not supported on all SDKs

For more information about the media modes, check out the Session Creation Overview.

For more information about end-to-end encryption in Routed Mode, check out the End-to-End Encryption page.

Adaptive Media Routing

Beginning with OpenTok.js v2.24.7, routed sessions are optimised to use adaptive media routing, if possible. Adaptive media routing determines if media can be relayed without the Media Router for one-on-one video streaming, to optimize the media performance between two participants. The routed session automatically adapts media routing to use the Media Router when required — for sessions with three or more participants, archiving, live-streaming broadcasts, SIP interconnect, Experience Composer, and Audio Connector.

Audio Fallback

In routed mode, the Vonage SDK automatically falls back to audio only mode if the bandwidth is too low to support video calls. However, if you want to override this behavior this is possible by setting audioFallback to false on the OT.initPublisher.

Getstats Method

In addition to implementing custom audio fallback mentioned above, getStats() polling can be used to capture information about the quality of the connection to display real-time information to the user as well as for troubleshooting purposes.

Vonage Inspector Tool

The Vonage Inspector Tool can be used to understand the media performance during the session, as well as which codecs, modes (relayed or routed), events and advanced features were used during the call.

Report Issue Method

It is possible to flag errors for later review in the inspector. The Report Issue ID can also be used to search inspector without knowing the sessionId.

Broadcast

The Video API gives users two options for publishing live videos to wider audiences - an interactive broadcast and a live-streaming broadcast.

Interactive Broadcast

This type of broadcast allows clients to interact with each other by subscribing to each other's stream. Important to note that this type of broadcast can support up to 15,000 subscribers in up to Full HD. Below are things to consider when using this broadcast:

  • Visit Vonage Scalable Video Simulcast to learn more about Simulcast. By default, Simulcast will kick in after the third connection joins the call (this is done to avoid Simulcast in one-to-one calls).

  • To override the default and disable scalable video for publishers in a routed session you can use the scalableVideo option in the OT.initPublisher() method. Keep in mind that the maximum number of subscribers will be impacted when publishers increase. To get the max subscribers consult the table on the “Live interactive video broadcasts” guide.

  • To ensure stability in large sessions, suppress connection events, see the “Suppressing connection events” guide.

  • Larger WebRTC sessions are possible when using the Experience Composer.

Live Streaming

This type of broadcast allows for more than 15,000 subscribers to subscribe to streams. There are two types of protocols available to broadcast video, RTMP (Real Time Messaging Protocol) and HLS (HTTP Live Streaming). Regardless of which one you choose, limit the number of publishers for a better viewer experience.

HLS vs RTMP

  • HLS supports an unlimited number of subscribers, whereas RTMP is limited by the RTMP delivery platform.
  • HLS is delayed by 15-20 seconds, whereas RTMP (from Vonage’s platform) is delayed by five seconds; this does not include the delay from RTMP delivery platform, however, as they too will induce delays based on how they process video.
  • Low Latency HLS (LL-HLS) is delayed by 4-6 seconds
  • HLS playback is not supported on all browsers, but there are plugins you can use, such as flowplayer. Playback allows users to go back, video scrubbing (rewind/fast forward) if you will, from the beginning of the live stream then back to the current live stream.
  • DVR mode can be activated when you create an HLS session. This is an Apple standard that allows users to Play/Pause and Resume Live HLS within a window of 2 hours.
  • HLS/RTMP has a default max duration of four hours. If the broadcast needs to go longer, change the max duration property (max is 10 hours).
  • HLS/RTMP streams automatically stop sixty seconds after the last client disconnects from the session.

To learn more about live streaming, such as layouts, max duration, and how to start/stop live streaming, visit the Live Streaming Broadcasts guide.

User Interface and User Experience Best Practices

In general, it is recommended to read and follow the UI Customization documentation and follow the sections that are relevant to your application.

Ensuring a Good User Experience

Precall Test

Add a precall test where users’ device and connection will be subject to network and hardware test prior to joining a session. Remember to generate new sessionIDs for every test and let the test run for at least 30 seconds for more accurate results.

The general Vonage Precall Test Tool can be used by you and your customers for generic connectivity tests to the Video API.

If you would like to integrate your own PreCall test and gather all the test data, there are several resources available to do so:

Video Stream Handlers

Completion Handlers can give you feedback when you try to connect, publish, subscribe or send signals to a video API session. They are described here:

You can also listen for exception events on the OT object, which will throw exception events for more general errors that are described in Exception Events

When the connection has been established, you would usually publish audio and video and also subscribe to other participants' streams. When managing the Publishers and Subscribers in regards to UI, you can make use of the respective events of the publisher and subscriber instances, which can help you display useful information to users when specific events or exceptions occur. Publisher and Subscriber events can be different and are described here:

Audio Fallback

Our media server constantly checks network conditions and if it detects an issue with end users’ connection, it will automatically drop the video and continue with audio only, if packet loss is greater than 15%; and, an event gets sent when this happens. It is recommended that such event is displayed on the UI alerting impacted users that the quality of their connection dropped, switching to audio only. The threshold to switch to audio-only is not configurable, more information can be found in these examples:

Audio fallback is enabled by default, however it can be disabled with the audioFallbackEnabled parameter. See here

Reconnecting to session

When a participant suddenly drops from a session due to network-related issues, it will attempt to reconnect back to the session. For a better user experience, it is recommended that such events are captured and properly displayed to the UI letting the user know that it is attempting to reconnect back to the session. More information can be found here.

Active speaker

For audio only session, try adding an audio level meter so that participants can have a visual of who the current active speaker/s is/are. For video, try changing the layout where the active speaker gets more screen real estate. You can use the audioLevelUpdated event that gets sent periodically to make UI adjustments.

Loudness detector

It is good practice to implement a loudness detector to identify when a given user who is muted is trying to speak. In this case, the audioLevelUpdated event will fire with audioLevel set to 0. Therefore, it’s necessary to use an AudioContext to avoid this situation.

Controlling resolution/frame rate

The Subscriber object provides methods to lower the received resolution and/or frame rate. This is useful in the context of saving bandwidth and CPU resources if you are displaying a large number of participants (e.g. more than 4 on a mobile or more than 8 on desktop)

Avoiding audio issues

On large calls participants can inadvertently introduce noise or echo into the call. The higher the number of participants the more likely this is to cause problems, therefore you could consider auto-mute on join logic and/or a mute all moderator button for larger sessions

Report Issue API

Reporting an issue allows the end consumer of the application to trigger a unique issue ID from the client side. Our customer can store this issue ID and that can be used when raising a ticket with support. The issue Id will help to identify the unique connection ID that reported the problem and focus the investigation from support.

Location hint

When creating a session, you can set a preferred region where the video call will be hosted. This can be useful for large sessions where you know most users will join from a specific region. Note that this does not guarantee a specific datacenter will be used, for that please see Regional Media Zones.

Enhancing In-Call Experience

  • Background Blur/Replacement - The JS SDK gives a simple method to blur the background or replace it with an image. For the latter please make sure the background image has the same aspect ratio as the published stream and be aware that the background may be cropped depending on the fitMode setting described here. Note that background blur and replacement is only supported in recent versions of Chrome, Electron, Opera, and Edge. It is not supported in other (non-Chromium-based) browsers or on iOS.

Should check if that's still the case

  • Media Processor - Use the Vonage Media Processor library to apply custom transformations to published video on desktop and mobile, including natively using our mobile SDKs. This supports background blur and replacement, but also more advanced use cases such as augmented reality and spatial audio.

  • Live Captions API - use this simple API to transcribe audio streams and generate real-time captions for your application. The Live Captions API lets you show live captions to end-users in a Vonage Video session, using a transcription service.

  • Audio Connector - using Audio Connector, you can send raw audio (PCM 16 khz/16bit) streams from a live Vonage Video session to external services such as AWS, GCP, Azure, etc, individually or mixed. You can also identify the speaker by sending the audio streams individually by opening multiple WS connections. Customers use this feature to build use cases such as medical transcriptions and real-time translation.

Engagement Features

  • Chat (text messaging) - you can send messages using Vonage’s signaling, but note that messages are not stored on Vonage’s video platform. When adding text messaging functionality, keep in mind that some users may arrive/join a session after text messages were sent; latecomers will be unable to view messages that were sent. Additionally, should you decide to record a session, text messages will not be captured, unless you implement Experience Composer.

  • Screen-share

    • Consider hiding the publisher that shares their screen to avoid the hallway-mirror effect.
    • ContentHint: allows you to optimise the screenshare to suit detail (such as slideware) or motion (such as a video).motion, detail, etc. This flag can and should be set after 2.20.

Experience Composer

We also provide tools for you to create a highly customised composed layout. This allows you to create Web applications to build rich UI/UX experiences for end users.

  • Create a web page which will be rendered on Vonage platform
  • Mix video content with any other web content, such as
  • Chat window
    • Whiteboard
    • Advanced content and layouts
  • Content can be dynamic and change throughout the session
  • Composed content can be published into other Video sessions, in order to record, archive, and broadcast, while keeping the rich UI/UX experiences delivered to users intact.

For more information see the Experience Composer documentation.

Archiving Best Practices

There are two types of offerings when it comes to recording, composed and individual streams.

Composed

  • Can record up to 16 video streams, plus an additional 34 streams where only the audio will be recorded, totaling 50 streams
  • Single MP4 file containing all media streams
  • Customizable layout
  • Screen recording and advanced layouts like custom overlays, montages and watermarks (see Experience Composer)
  • Can be started automatically (240 minutes max. If recording is not stopped, it will start archiving to a new file)
  • It is possible to prioritize certain streams to be included in the recording by assigning different layout classes.
  • Supports SD, HD and FHD formats.

Individual Stream:

  • Can record up to 50 streams, both audio and video
  • Multiple individual streams/files saved in a zip folder
  • Intended for use with a post-processing tool to produce customised content
  • Cannot be started automatically

Storing archives

Vonage will retain archives for 72 hours if uploading fails, cloud storage has not been configured, or the disable option for storage fallback was not selected. Keep in mind that should you decide not to enable upload fallback and uploading fails for whatever reason, that archives will be not recoverable.

Archiving FAQs

  1. Are archives encrypted?

Not by default. But one can add an encryption feature for composed archives. To learn more, visit Archive Encryption

  1. Can you record just the audio or just the video?

Yes. Using the REST API, set the hasVideo/hasAudio parameters to true or false.

  1. Can I name the archive so that I can identify them by name?

Yes. Using the REST API, set the name to the desired identifier.

  1. How can I check archives’ status?

Use the archive inspector.

  1. Can I record certain streams from a session?

Yes, please see Selecting streams to be included in an archive.

  1. Can I record in different formats at the same time?

Yes, you can initiate archiving more than once for a given session. This means for example you could record a composed layout at the same time as having a separate recording per participant (i.e. Individual archiving)

Quality, Performance and Compatibility

  • Devices - for multi party sessions, try to limit the number of participants, as more participants requires more processing power. We recommend the following number of participants:

    • Mobile = 4 (Engineering official statement supports up to 8 max)
    • Laptop = 10
    • Desktop = 25

  • Controlling resolution/frame rate - The Subscriber object provides methods to lower the received resolution and/or frame rate. This is useful in the context of saving bandwidth and CPU resources if you are displaying a large number of participants (e.g. more than 4 on a mobile or more than 8 on desktop)

  • Bandwidth requirements see "What is the minimum bandwidth requirement to use the Vonage Video API?"

  • Proxy - if users can only access the internet through a proxy, make sure that it is a “transparent” proxy, else it must be configured in the browser for HTTPS connection, given webRTC does not work well on proxies requiring authentication. Check out our network check flow in Restricted Network Guidelines

  • Firewall - the article "What are the Vonage Video API network connectivity requirements?" contains more information on the optimal ports for the fastest call setup time and the best quality video.

  • Codecs- Vonage supports VP9, VP8 and H.264 codecs; see the Codecs guide for more information on the differences between each codec.

Session Monitoring

Session monitoring allows you to register a webhook URL. Use this feature to monitor sessions and streams - an example of this is limiting the number of participants in a session, this is often used alongside forceDisconnect function. The moderator can also call an action to the server and have it do a REST call to force disconnect.

  • It can also be used to track usage, however for better usage tracking, use the Insights API.

  • If within 30 minutes there are more than 50 event delivery failures (in which we don't receive a 200 success response when sending an HTTP request to your callback URL), we will disable session monitoring event forwarding. We will send an email if this occurs. You can re-enable session monitoring in your account page.

  • ConnectionCreated: you can use ConnectionData to identify users' connections. For example, you can pass the user ID, name, or other data describing the client (Do not use personal information in token data)

Add-ons

Most customers can purchase (or remove) add-ons with a single click, configured via the self-service tool.

Security and Privacy

The Vonage Video API can be customized to meet the highest security standards. Our platform is GDPR compliant and we are HIPAA compliant. For European customers, we are offering extended add-ons that make it possible to comply with additional local certifications and standards, such as KBV certification (Germany) or other privacy laws that aim for better data ownership & protection (Europe-wide).

Read more about:

On request and under NDA, we can provide further reports such as the Data Transfer Impact Assessment, SOC2 Type 2 audit report, and External Pen Tests that prove the high-security standards of our Video platform.

Pricing

Where can I get more help?

If you have any questions, you can join our Developer Community on Slack, or alternatively contact our API support team.