Microsoft Teams Business Voice with Calling Plan: Direct Routing Tip

As you are likely aware Microsoft Teams Business Voice comes in two versions in the UK, with Calling Plan and without. At the time of writing Microsoft Partners who have the Small and Midmarket Cloud Solution competency have Business Voice included as part of their Internal Use Rights (IURs). The UK IUR licensing comes with Microsoft Calling Plan. I mention this as the scenario discussed below applies to both standard and IUR Business Voice licensing.

Even though they have Microsoft Calling Plan use rights some customers/partners may still want to assign an on-premises phone number to one or more of their users. An example scenario might be a Microsoft UK Partner with Business Voice IURs who wants to use their own Direct Routing service for PSTN calls.

This is perfectly legal but even if Direct Routing is set up correctly and the user is assigned their on-premises number I’ve seen this configuration fail. Why? The short video below contains the answer.

The resolution may seem trivial with hindsight but it’s an easy step to overlook!

On-network Conferencing for Microsoft Teams Audio Conferencing

On-network conferencing for Microsoft Teams is simply the ability to make calls to Audio Conferencing Service numbers across an organisation’s Direct Routing deployment. For example, this might be handy during a migration project if you want PBX end users to be able to dial into Teams Meeting from existing 3rd party IP, Digital or Analogue handsets.

As shown in the video below the On-net conferencing feature supports both dial-in and dial-out from Teams Meetings. The dial-out function is enabled by creating an Audio Conferencing routing Policy (New-CsOnlineAudioConferencingRoutingPolicy) and assigning it to end users. For more information please refer to the documentation.

Note: At the time of writing this capability is currently in Public Preview.

Microsoft Teams Voice in Regulated Environments

As you are probably some countries have implemented a regulatory framework that prohibits customers implementing toll bypass within their own telephony environments. In this blog I am going to share a short 5 minute video that introduces Locations Based Routing (LBR), which is a technology that can be used in this type of deployment scenario.

Strong Warning: It is the responsibility of the Microsoft Partner and/or Customer to take counsel to ensure any given LBR implementation meets the legal requirements of the country it is being deployed in.

As mentioned in the video, the lab Direct Routing implementation used non-media bypass. In production scenarios it is very likely a media bypass probably with Local Media Optimisation (LMO) would be configured. I’ve previously posted a blog about LMO here.

To find out more about Locations Based Routing, please refer to the Microsoft documentation.

Managing Direct Routing Voice Quality for Microsoft Teams

For customers that need to manage their own on-net voice quality for Microsoft Teams, Direct Routing offers an option for Local Media Optimisation (LMO). The overarching principle is that by determining an end user’s location, when on the corporate network, the system will allow the voice path to be negotiated between the Teams client and the internal IP address of one of the customer’s (certified) SBCs. Hence, keeping the media within the customer’s domain, which allows QoS to be applied and honoured for PSTN calls.

Users who are roaming outside of the Enterprise network will establish a voice path with the public IP address of one of the corporate SBCs. Or via a Transport Relay Point if the customer’s security policy blocks direct inbound access to the SBCs.

Behind the scenes the Microsoft Teams platform uses a predefined virtual topology and “trusted IP addresses” to identify on a call by call basis whether the end user is either inside or outside of the corporate network. Depending on the location SIP X-MS headers will be used to tell the SBC where the Teams client is located.

This is an advanced configuration so I created the video demonstration below to help me explain the basic concepts. If this is a new area for you. I hope it helps!

For additional information, please check out the Microsoft documentation. After taking some time to review my video it should make for easier reading.