Network Flows Simplified: Teams Direct Routing Explained

Direct Routing connects your existing phone system to Microsoft Teams through a Session Border Controller.The Session Border Controller, or SBC, acts as a bridge between your on-premises phone system and Teams.The SBC performs several critical functions. It handles media transcoding, acts as a security gateway, translates protocols, and manages call routing.For incoming calls, external calls first reach the SBC through your existing phone system.The SBC then authenticates with Microsoft Teams and translates the call protocols.Finally, the call is routed to the appropriate Teams user.For outgoing calls, when a Teams user dials an external number, Teams routes the call to your designated SBC.The SBC receives the call from Teams and prepares it for external routing.Finally, the SBC connects the call to the external phone network.To implement Direct Routing, organizations must meet specific licensing requirements.The Phone System license is essential, which comes included with Microsoft 365 E5 or as an add-on to E3. Teams licensing is also required through either E3 or E5 subscriptions.Audio Conferencing licenses are optional but recommended for PSTN dial-in capabilities.Let's examine the network requirements for optimal voice quality.Each Teams call requires 65 kilobits per second of bandwidth. Round-trip time should be less than 100 milliseconds, with packet loss under 1 percent and jitter below 30 milliseconds.Session Border Controllers must meet specific certification requirements.Only Microsoft-certified SBCs can be used, supporting features like TLS 1.2, IPv4 and IPv6, media bypass, and high availability configurations.Regular firmware updates are crucial for maintaining security and compatibility.SBC firmware versions must be kept current, with updates typically released quarterly to address security patches and feature enhancements.Let's examine how calls flow through Teams Direct Routing, starting with inbound calls.Voice routing policies determine how calls are handled. These include PSTN usage, voice routes, number patterns, and gateway assignments.Number translation rules convert phone numbers between different formats to ensure proper routing.Failover configuration ensures business continuity by automatically switching to a backup SBC if the primary fails.Emergency calling requires special configuration to ensure accurate location information reaches emergency services.Let's review common troubleshooting scenarios and their solutions.Let's review the key points about Teams Direct Routing configuration and call flows.Thanks for learning about Teams Direct Routing with Spark.E!