Microsoft Edge浏览器下WebRTC+Skype Web SDK的DTMF问题咨询

Hi Peter, let's break down your questions one by one based on my hands-on experience with Skype Web SDK, Edge browser behavior, and Skype for Business Server configurations:

Yes, there are known DTMF-related compatibility gaps between certain Edge versions and the Skype Web SDK, especially with older EdgeHTML-based builds (pre-Chromium Edge):

• Early EdgeHTML versions had limited support for WebRTC's RTCDTMFSender API, which the Skype Web SDK relies on for DTMF transmission. This often led to issues like unencoded DTMF tones, failed transmission, or incorrect recognition on the receiving end—unlike IE11, which uses a legacy ActiveX-based path for Skype Web SDK functionality that handled DTMF reliably.
• For Chromium-based Edge (the current standard version), while WebRTC support is much more robust, some older versions of the Skype Web SDK might not have full optimization for its DTMF implementation. If you're using this newer Edge, try updating your Skype Web SDK to the latest available release, and verify that your code correctly initializes RTCDTMFSender with standard parameters (like a tone duration of 160ms and gap of 100ms, which are widely compatible).

Absolutely, you can capture DTMF tones on Skype for Business Server, but it requires specific configuration or custom development:

• Built-in recording: Enable call recording for your deployment—this will capture DTMF tones as part of the call audio stream. You can configure this via Skype for Business Server Control Panel or PowerShell cmdlets (like Set-CsUserCallingSettings for user-level recording, or Set-CsCallRecordingConfiguration for global settings).
• CDR/QoE limitations: By default, Call Detail Records (CDR) and Quality of Experience (QoE) logs don't store individual DTMF keystrokes—they only track call metadata. To get granular DTMF data, you'll need to use call recording or custom tools.
• Custom integration: Use the Unified Communications Managed API (UCMA) to build a custom application that listens to call events and extracts DTMF signals in real time. For Skype for Business Online (now part of Microsoft Teams), you can also use the Microsoft Graph API's call recording endpoints to retrieve DTMF data, provided you have the appropriate permissions.
• Note: Always ensure your DTMF recording practices comply with local data privacy regulations, as this may involve capturing sensitive user input.

内容的提问来源于stack exchange，提问作者Peter