SBC, or Session Border Controller, is a critical component for ensuring communication between your company's internal phone system and Microsoft Teams via Direct Routing. It functions as a protective boundary between the two environments, handles SIP signaling, encrypts media traffic with SRTP, and maintains secure communication through TLS.

What is an SBC and why do you need it for Teams

SBC is used to control and protect SIP traffic flowing between your local phone system and Microsoft's cloud telephony services. It enables Direct Routing, which means calls can be routed directly to Teams without going through Microsoft's public telephone infrastructure.

Choose SBC hardware: AudioCodes Ribbon vs software

To choose between AudioCodes Ribbon or a software-based solution, consider factors such as scalability, cost, and technical requirements. AudioCodes offers robust hardware solutions with high performance, while software-based alternatives can be more flexible and easier to scale.

Basic SBC configuration against Internetport sip.internetport.se

  1. Step 1: Log in to your SBC administration page

    Use the credentials you have to log in.

  2. Step 2: Configure SIP trunk against Internetport

    Navigate to SIP trunk settings and add a new trunk with server address sip.internetport.se, ports 5060 UDP / 5061 TLS, and supported codecs such as G.711 a-law (PCMA), G.711 u-law (PCMU), G.722, G.729.

  3. Step 3: Use STUN server for NAT traversal

    Configure the STUN server stun.internetport.se to handle Network Address Translation (NAT).

Configure SBC against Microsoft Teams infrastructure

  1. Step 1: Create a new SIP trunk in Microsoft Teams Admin Center

    Navigate to SIP routing rules and create a new trunk with the necessary information.

  2. Step 2: Configure SBC to connect to Microsoft's SIP servers

    Use the SIP credentials you obtain from portal.internetport.com -> Services -> My services -> [SIP trunk] -> Configuration details.

TLS and SRTP for signaling and media

To ensure communication, both TLS for SIP signaling and SRTP for media traffic are required. Make sure your SBC is correctly configured for both protocols.

Verify SBC connection against best practices

  1. Step 1: Test SIP signaling

    Use tools like sip-tester to verify that SIP signals are flowing correctly.

  2. Step 2: Check media traffic

    Check that audio is flowing correctly by performing a test call to a number you know works.

Troubleshoot TLS certificates, media flow, NAT

  • Verify that TLS certificates are valid and installed correctly on the SBC.
  • Check media traffic using tools like wireshark.
  • Check NAT settings to ensure traffic is not being blocked.

For more help and support, visit Internetport's support page.