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How Microsoft 365 Enables Voice for All-in-One Communications

A part of Microsoft 365, Microsoft Teams is a unified communication and collaboration platform that combines persistent workplace chat, video meetings, file storage, and application integration. 

But Teams can also be your phone system. That’s right, Microsoft has created a way for the Teams platform to be used as a fully-fledged business phone system.

The cloud-based Microsoft 365 Enterprise Voice solution enables you to transform how work gets done by unifying calling, chat, meetings, calendar, and email for an all-in-one communication and collaboration system.

Simply enable Microsoft Phone System licenses (included in or as an add-on to your Microsoft 365 subscription) to take advantage of all of the calling features needed by enterprise organizations.

Microsoft 365 offers two ways to make and receive calls:

  • Microsoft Calling Plans – Created and maintained by Microsoft in the cloud, Calling Plans provide a license, a new phone number, and a pool of minutes for each user with no additional PSTN costs or carrier contracts. Only available in a few countries and with limited support, this option requires you to either assign new phone numbers to users or port existing phone numbers.
  • Microsoft Direct RoutingDirect Routing enables you to connect your existing telecom provider and phone numbers to Teams virtually anywhere for a full-featured office phone system. The advantages include less expensive call rates, more flexibility, and better support. Direct Routing also allows integration with existing on-premise phone systems.

How does Direct Routing work?

Direct Routing works by connecting Microsoft 365 to the PSTN using two key components: 

  • Session Border Controllers (SBCs) – An SBC is a device deployed in VoIP networks to provide control over the signaling and media streams involved in setting up, conducting, and tearing down telephone calls or other interactive media communications. They protect against Denial of Service (DoS) and Distributed DoS (DDoS) attacks, safeguard against toll fraud and service theft, and provide media and signaling encryption to ensure confidentiality and protect against impersonation/masquerade.
  • Service Provider SIP Trunks – SIP trunking sends voice and other unified communications services over the Internet. It works with an IP-enabled PBX (private branch exchange) and replaces traditional telephone lines or PRIs (Primary Rate Interfaces).

3 Direct Routing scenarios

On-premises-based SBC with a local PSTN or SIP trunk

Use existing telephony arrangements with your service provider(s), eliminating the need to cancel contracts, which can be costly.

Integration with an existing on-premises phone system

Configure interoperability between your organization’s telephony equipment—such as a third-party PBX, Unified Communications systems (Cisco UCM), analog telephony devices, and the Microsoft Teams Phone System—for a phased migration to Microsoft Teams.

Cloud-based PSTN provider

Connect through a vendor, like TetraVX, that provides both the SBC and SIP trunking for one monthly price (including Managed Services Support).

Use cases for Direct Routing

Organizations that plan to use their Teams platform for voice communication but need more flexibility than Microsoft’s pre-set calling plans deliver should consider Direct Routing. You should also consider Direct Routing if you:

  • Are heavily invested in Microsoft Teams – Businesses that have already made an investment in adopting and implementing Microsoft Teams for their internal communications can more easily use the platform for their external communication. This could also mean less of a need for a separate PBX and all the associated costs.
  • Have limited in-house expertise – Businesses with limited or no IT support staff may want external support for Teams as a voice system. Partners like TetraVX can provide full managed services support for Microsoft 365 Enterprise Voice in Teams including troubleshooting voice issues.  
  • Require flexibility in calling plans – Microsoft’s calling plan offers little flexibility and the plans cannot be altered. Direct Routing allows businesses to choose their own service provider, which is especially important if international calling is needed.
  • Need to integrate with an existing phone system – Direct Routing enables integration with an existing on-premises phone system—ideal for calling between Teams users and users with traditional desk phones connected to a PBX and for placing external calls from both Teams and existing traditional handsets. You can also extend your existing phone system into Teams by providing voicemail in Teams and/or allowing dual ring on traditional desk phones and the Teams client on their desktop or mobile device.
  • Require conference room systems – Direct Routing can also allow existing or new conference room solutions, such as Surface Hub or Microsoft Teams Room, to be connected to the PSTN network for either dial-in access or dial-out capabilities.

Logicalis: Expert at building an all-in-one calling and collaboration solution

A longtime Microsoft Gold Partner, Logicalis can help you design, implement, and manage your Teams environment, including an Enterprise Voice solution that delivers all-in-one communications and collaboration for your organization.

Logicalis can also help you develop a training plan to help employees get up to speed on your new voice system and enable user adoption that maximizes your investment. Take advantage of a complimentary, personalized Collaboration Workshop, with your experts and ours, and receive recommendations for next steps.

Download the datasheet to learn more or contact us to see how we can help you build a comprehensive communication and collaboration solution for your organization.

Troy Sempsrott is Director of Architecture at Logicalis, responsible for go-to-market strategies and solution development for networking and collaboration.