In recent times Microsoft and Cisco have been working closly together, due to this relationship Cisco using their Cisco Unified Border Element or CUBE as it is known is now supported for Direct Routing with Teams. This is Cisco’s first version but should help Cisco houses in moving to Microsoft Teams or if organisations want the best of both worlds. Currently it will not support Media Bypass however this is an expected feature in a future release.
The current supported models are CUBE 1000, 4000, 1000V series Integrated Services Routers and 1000 series Aggregation Services Routers running IOS XE Amsterdam 17.2.1r.
For more information refer here – https://docs.microsoft.com/en-us/microsoftteams/direct-routing-border-controllers