How to connect analog devices to Microsoft Teams?

In this post I give you an architectural overview on how you can connect analog devices, e.g. fax machines, analog phones, door bells, intercoms etc. to Microsoft Teams.

Preamble

First of all, I’d recommend to please get rid of your analog devices. Let me guess you are probably reading this because you have some of these poor and legacy analogs which you cannot get rid of for some reasons?

  • If this is the case:
    Well, ok, let’s go ahead to keep your existing investments in analog devices and get it to work.
  • If not, i.e. you can get rid of them:
    Skip this post and read something more interesting. 😉

Goal

The goal is to add analog devices to a Microsoft Teams voice/telephony deployment.

Use Cases – Analog Telephony with Teams user and PSTN

The uses cases are defined as follows:

  1. call from an analog device to a Teams user
  2. call from a Teams user to an analog device
  3. call from an analog device to a PSTN (external) phone (number) [e.g. mobile phone]
  4. call from a PSTN (external) phone to an analog device

Architecture Overview

In this architectural sketch you can see a high level Microsoft Teams Direct Routing deployment including an analog device which is connected via an anlog [device] gateway.

It includes

  • [left] PSTN sip trunk [from your PSTN provider of choice],
  • [center] a (certified) session border controller (SBC),
  • [center] a analog [device] gateway
    • sip trunk between analog gateway and SBC
    • analog link (FXS, RJ11) between analog gateway and analog device
  • [center-right] analog device [connect to analog gateway]
  • [right] a Microsoft Phone System sip trunk
  • [right] a Microsoft Teams User

Requirements

What are the requirements for this? To keep it short, you need:

  1. Teams Direct Routing (TDR) [for details, please see Plan Direct Routing]
  2. Analog [Device] Gateway

Note: In case you have Microsoft Teams and utilize calling plans for telephony already but need these analog devices added you can add Teams Direct Routing to what you’ve got already.

Conclusion, opinion and summary

To sum this up, to connect analog devices to your Microsoft Teams deployment you need Teams Direct Routing (TDR). Then you can attach an analog device to an analog (device) gateway which is linked to a certified SBC for Direct Routing which handles the voice routing (from/to PSTN/Microsoft Phone System/analog gateway).

Additional resources