Your network and Azure Communications Gateway

Azure Communications Gateway sits at the edge of your network. This position allows it to manipulate signaling and media to meet the requirements of your networks and your chosen communications services (for example, Microsoft Operator Connect or Zoom Phone Cloud Peering). Azure Communications Gateway includes many interoperability settings by default, and you can arrange further interoperability configuration.

Tip

This section provides a brief overview of Azure Communications Gateway's interoperability features. For detailed information about interoperability with a specific communications service, see:

Role and position in the network

Azure Communications Gateway sits at the edge of your fixed line and mobile networks. It connects these networks to one or more communications services. The following diagram shows where Azure Communications Gateway sits in your network.

Architecture diagram for Azure Communications Gateway connecting to fixed and mobile networks

Azure Communications Gateway provides all the features of a traditional session border controller (SBC). These features include:

  • Signaling interworking features to solve interoperability problems.
  • Advanced media manipulation and interworking.
  • Defending against Denial of Service attacks and other malicious traffic.
  • Ensuring Quality of Service.

Azure Communications Gateway also offers metrics for monitoring your deployment.

Network requirements

We expect your network to have two geographically redundant sites. You must provide networking connections between each site and:

  • The other site in your deployment, as cross-connects.
  • The Azure Regions in which you deploy Azure Communications Gateway.

Connectivity between your networks and Azure Communications Gateway must meet any relevant network connectivity specifications.

  • We strongly recommend using Microsoft Azure Peering Service Voice (also called MAPS Voice or MAPSV).
  • If you can't use MAPS Voice, we recommend ExpressRoute Microsoft Peering.

The following diagram shows an operator network using MAPS Voice or ExpressRoute (as recommended) to connect to Azure Communications Gateway.

Diagram that shows Azure Communications Gateway in two regions connecting to two sites in the operator network. The two sites in the operator network have cross-connects between them. The connections between the operator network use MAPS Voice or ExpressRoute, as recommended.

For more information, see:

SIP signaling support

Azure Communications Gateway includes SIP trunks to your own network and can interwork between your existing core networks and the requirements of your chosen communications service.

SIP trunks between your network and Azure Communications Gateway are multitenant, meaning that traffic from all your customers shares the same trunk.

To allow Azure Communications Gateway to identify the correct service for a call, you must configure the details of each number and its service(s) on Azure Communications Gateway. This is:

  • Required for Microsoft Teams Direct Routing and Zoom Phone Cloud Peering.
  • Not required for Operator Connect (because Azure Communications Gateway defaults to Operator Connect for fixed line calls) or Teams Phone Mobile.

You can also configure Azure Communications Gateway to add a custom header to messages associated with a number. You can use this feature to indicate the service and/or the enterprise associated with a call. This feature is available for all communications services except Azure Operator Call Protection Preview and Teams Phone Mobile.

This configuration requires you to use Azure Communication Gateway's browser-based Number Management Portal (preview) or the Provisioning API (preview).

Note

For Operator Connect and Teams Phone Mobile:

  • We strongly recommend integrating with the Provisioning API. It enables flow-through API-based provisioning of your customers in the Operator Connect environment, in addition to provisioning on Azure Communications Gateway (for custom header configuration). Flow-through provisioning interoperates with the Operator Connect APIs, and allows you to meet the requirements for API-based provisioning from the Operator Connect and Teams Phone Mobile programs. For more information, see Provisioning and Operator Connect APIs.
  • You can't use the Number Management Portal after you launch your service, because the Operator Connect and Teams Phone Mobile programs require full API integration.

You can arrange more interworking function as part of your initial network design or at any time by raising a support request for Azure Communications Gateway. For example, you might need extra interworking configuration for:

  • Advanced SIP header or SDP message manipulation.
  • Support for reliable provisional messages (100rel).
  • Interworking between early and late media.
  • Interworking away from inband DTMF tones.

RTP and SRTP media support

Azure Communications Gateway supports both RTP and SRTP, and can interwork between them. Azure Communications Gateway offers other media manipulation features to allow your networks to interoperate with your chosen communications services. For example, you can use Azure Communications for:

  • Changing how RTCP is handled.
  • Controlling bandwidth allocation.
  • Prioritizing specific media traffic for Quality of Service.

For full details of the media interworking features available in Azure Communications Gateway, raise a support request.

Next steps