Change to SDP Unified Plan in Chrome

TL;DR: To prevent any potential issues with Chrome 72 we recommend that clients use the latest 2.15.6 JS SDK release.

With the recent release of Chrome 72 there is a change in its internal behaviour related to conformance with the WebRTC standard. In Chrome 72 the default SDP Semantics have changed from Plan B to Unified Plan. This change relates to how WebRTC clients negotiate codecs between themselves and does not affect how you use the OpenTok APIs. Taking care of ongoing browser changes is one of the benefits of using OpenTok APIs.

We have done extensive testing of OpenTok with Unified Plan and have not found any issues. However to be safe we have decided to update our JS SDK to request that Chrome 72 continues to use Plan B. This change is in our latest 2.15.6 release. If you experience issues please ensure you are using this latest version. If you continue to see issues once you are using the 2.15.6 JS SDK please do let us know so we can be aware of them and fix them.

We plan to start using Unified Plan across browsers in the future, after we have had adequate time testing the changes across different browser vendors and versions. You can find out more information about this change in Chrome 72 at


The TokBox Team


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