Options for Dialing on Microsoft Teams

several different device icons in bubbles all being connected to a centered cloud bubble

Sep 19, 2018 by Leah Weisman

Microsoft Teams, collaboration tool, Slack killer … phone system?

If you’re unfamiliar with Teams, get out from under that rock! Just kidding. Microsoft Teams is a platform that combines workplace chat, meetings, notes, attachments, planning and so much more. It comes with Office 365 and it is Microsoft’s latest focus.

Microsoft is aiming to centralize all your communication and collaboration into one pane of glass, so the IM and calling functionality you’re used to using in Lync or Skype for Business (or Jabber) will all be rolled into Teams.

There are many questions about how you get your dial tone set up in Teams. We wouldn’t be consultants if we didn’t tell you “it depends” when you ask which way is the best way to go about it. There are several options and depending on pricing, organization size, and/or use case, one may be easier or more affordable than the others.

First, let’s discuss the Direct Routing options. Direct Routing is the fancy terminology for having an on-premise signaling with Microsoft Teams phone system. This means that you can keep your current provider and still utilize Teams calling.


If you’re currently using a PRI, you can keep it if you really want to. Maybe you have to, based on location or lack of availability of other services. Just be aware each PRI only allows for 23 concurrent calls.

If you keep your own PRI, you’ll need Microsoft Office 365 E3 licenses with the phone system add-on or E5 in order to get the Teams app with calling functionality.

SIP Trunking

SIP trunking services typically provide a bit more flexibility, whether it is over IP or telco-based. Moving your SIP trunk is generally easier if your physical location changes. If you have SIP over IP, it is simply a matter of pointing the trunk at a new public IP. If your SIP is telco-based, then hardware will still need moving, but will typically have shorter lead times than PRIs.

With SIP trunking, you can also define how many concurrent calls you want.

To use Teams dialing with third-party SIP services, you must have at least Office 365 E3 with the phone system add-on license or E5 for each user.

One of the major benefits of utilizing Direct Routing in PRI or SIP trunk configuration is the ability to have a much larger number of users without having to pay for a separate domestic dialing license for each. For larger organizations, this cost difference could be the deciding factor in how you have your telephony delivered.

Use Microsoft Office 365 SIP services

There is an option where you can roll it all up to Microsoft. You can port your numbers over and simply pay your monthly Office 365 licensing to get all your dialing and Teams functionalities (along with the productivity suite and some other neat tools like SharePoint). For this, you will have to provision an Office 365 E5 license and a domestic dialing add-on to each user you want to be able to make calls. For international dialing, you will need either communication credits purchased through your Office 365 portal or the international dialing add-on license.

All three options are viable but there are caveats to bear in mind, like dealing with analog devices such as faxes, alarms and elevators. Currently, Office 365 Direct SIP does not provide for connectivity for analog devices. Therefore, an analog line would still need to be provisioned separately through your local carrier. One of the benefits of using Direct Routing with your existing PRI or SIP trunk is that we can implement an analog gateway like an AudioCodes MediaPack, or, if your SBC provides FXS ports, we can provide outbound and inbound connectivity for all of those legacy analog devices.

If you want to start planning how your organization will adopt Teams, send us an email or give us a call at 502-240-0404 and we’ll help you get started!

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