Configure Direct Routing in Microsoft Teams

Direct Routing

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1 Determine which PSTN connectivity will be deployed for your organization’s locations Microsoft provides alternative methods to provide PSTN connectivity for your users using Office 365 Phone System.
  • Phone System with Calling Plans (“Calling Plans”): Skype for Business Online and Teams
  • Phone System Direct Routing (“Direct Routing”): Teams only
  • Phone System with on-premises PSTN connectivity: Skype for Business Online only
  • Skype for Business Cloud Connector Edition: Skype for Business Online only
Direct Routing gives organizations the same benefits as Calling Plans, except that PSTN connectivity is facilitated by a third-party provider rather than Microsoft. This allows for deployment in countries where Calling Plans aren’t available, or in deployments where an existing PSTN service provider contract needs to be maintained or interoperability with certain on-premises systems is required.

Determine which option(s) are most suitable for your organization.
Country and region availability for Audio Conferencing and Calling Plans

Onboarding checklists for Audio Conferencing and Calling Plans
2 Verify your list of users and deployment cadence for enabling Direct Routing Check that you have a list of business units or sites in scope for Direct Routing with Teams. Using the objectives and key results model, work out which users will be in scope for Direct Routing. We recommend that you work on a site-by-site basis, so you can focus your resources.

As part of your enablement plan, identify which users you’ll enable, by when (Pilot, Site 1, Site 2, and so on).
Direct Routing envisioning
3 Plan and obtain licenses Users of Direct Routing must have the following licenses assigned in Office 365:
  • Skype for Business Online (Plan 2)
  • Microsoft Phone System
  • Microsoft Teams
  • Microsoft Audio Conferencing
Direct Routing also supports users who are licensed for Calling Plans. Phone System with Calling Plans can route some calls by using the Direct Routing interface.

The Audio Conferencing license is required for adding external participants to scheduled meetings, either by dialing out to them or by providing the dial-in number.
Direct Routing licensing
4 Plan for the session border controller (SBC) domain names The SBC domain name must be from one of the names registered in “Domains” of the tenant.

Note: You can’t use *.onmicrosoft.com for the fully qualified domain name (FQDN) of the SBC.

The SBC domain name is also important in planning the certificates required for each SBC.
SBC domain names
5 Plan for the certificates We strongly recommend that you request the certificate for the SBC by generating a certification signing request (CSR).

The certificate needs to have the SBC FQDN in the subject, common name, or subject alternate name fields. Alternatively, Direct Routing supports a wildcard in the common name or subject alternate name.

For specific instructions on generating a CSR for an SBC, refer to the documentation provided by your SBC vendor.

The article in the Additional information column lists supported root certificate authorities.
Public trusted certificate for the SBC
6 Plan for and configure the firewall ports The connection points for Direct Routing are the following three FQDNs:
  • sip.pstnhub.microsoft.com
  • sip2.pstnhub.microsoft.com
  • sip3.pstnhub.microsoft.com
The traffic between these connection points and your SBCs must be allowed on your corporate firewalls. You define the TCP port on the SBC when you configure the SBC.

Media traffic is on UDP. This type of traffic flows to and from media processor components. Bidirectional traffic between the SBCs and the media processors must also be allowed on your firewalls.

Note: The media processors have dynamic IP addresses, and the static IP address will be available later. It’s important that you allow any IP address listed in the Azure Datacenter IP Ranges.
SIP Signaling: FQDNs and firewall ports

Media traffic: IP addresses and port ranges

Azure Datacenter IP Ranges
7 Configure SBCs Microsoft only supports the certified SBCs to pair with Direct Routing.

Configure SBCs by using vendor-specific guidance and the instructions in the article in the Additional information column.
Supported Session Border Controllers (SBCs)
8 Pair SBCs with Direct Routing SBCs in each site must be paired with Direct Routing to provide dial tone and PSTN calling capabilities by using your own trunks.

Validate the SBC in that specific site is already paired with Direct Routing or configure the pair if not performed before.

Microsoft supports only the certified SBC's to pair with Direct Routing. Validate the SBC in that site is certified.
Pair the SBC to Direct Routing Service of Phone System
9 Validate SBC pairing Run the Get-CsOnlinePSTNGateway cmdlet for each SBC you paired for the specific site and verify that the parameter Enabled displays the value True.

Use the SBC management interface to verify that the SBC gets 200 "OK" responses to the outgoing SIP OPTIONS.
10 Validate user configuration Verify that the user accounts are either created directly in Office 365 or synchronized to Office 365 by using Directory synchronization.

Verify that the necessary licenses are assigned to the users.

For PSTN connectivity with Direct Routing, your users must be homed in Skype for Business Online and enabled for Microsoft Teams.
Enable users for Direct Routing Service
11 Configure users’ phone numbers All users who are in scope for Direct Routing must be assigned their phone numbers and voicemail.

Use Set-CsUser cmdlet to enable voicemail and assign phone numbers to your users.
Configure the phone number and enable enterprise voice and voicemail
12 Configure voice routing Phone System has a routing mechanism that allows a call to be sent to a specific SBC based on:
  • Called number pattern
  • Called number pattern + Specific User who makes the call
Configure voice routing for the users by creating:
  • Voice Routing Policies
  • PSTN Usages
  • Voice Routes
  • Online PSTN Gateways
Configure Voice Routing
13 Set Microsoft Teams as the preferred calling client for the users Before a user can see the Calls tab in Microsoft Teams, you need to enable private calling for the tenant in Microsoft Teams and the Teams client must be configured as the preferred calling client for the users. Enable Calling for Microsoft Teams

Set Microsoft Teams as the preferred calling client for the users
14 Enable users for Direct Routing Assign the voice routing policies to the users who will make and get PSTN calls by using Direct Routing through the configured SBC. Enable users for Direct Routing Service
15 Prepare and execute user acceptance testing Prepare and execute user acceptance tests, including dial-in and dial-out scenarios. Test cloud voice workloads in Teams
16 Report usage, health, key success indicators (KSIs), and quality Report on usage, health, KSIs, and quality as you defined them during the Envision phase. Operations Guide

Next steps

After you complete this checklist, you’ll have successfully configured Direct Routing with your Teams deployment.

As the next step, use the Site Enablement Playbook for Voice (Playbook) to help you onboard your users on each site, and help ensure that you plan and execute important site-specific activities.