The audio conferencing section has a global configuration for Skype for Business meetings. These settings can also be overridden on a per-user basis. It's also worth noting that many settings for audio conferencing can't be set globally using the website, and you will need to configure them for each user individually. We'll go into more detail on configuring audio conferencing user settings a bit later.
Microsoft provides a couple dozen conference bridges worldwide. Depending on your tenant settings, you may also see several dedicated service numbers assigned to your company for use with conferencing, as shown in the following screenshot:
Audio-conferencing: Microsoft bridge
The table will identify Dedicated and Shared numbers, as well as Toll numbers versus Toll-Free. The assignment of Dedicated and Toll-Free numbers is handled in the voice section.
The only really useful thing you can do from this screen is to specify the default bridge, which is the number...