Planning Teams dial plans for Teams Phone

APPLIES TO: Microsoft Calling Plans, Operator Connect, Teams Phone Mobile, and Direct Routing

This article is for IT Admins and IT Pros who are researching and planning to use:

• Teams dial plans (with normalization rules) for ensuring user-dialed numbers get processed into a standard phone number format.

An overview of outbound and inbound called number processing is provided for context in relation to how Teams translates called numbers so that they can be processed for routing to a person or to a PSTN resource.

Understand the concepts in this article are a prerequisite for creating Teams dial plans and normalization rules.

What are dial plans?

Dial plans are what enables Teams to process and route phone calls dialed by users, regardless of the number-format used when the user entered the numbers to dial.

For example, a Teams user may enter a dialed number that is familiar to them, such as 333-4444. With a dial plan, Teams can identify the number entered format and translate the dialed number into a standardized format, such as +1-222-333-4444, for further routing.

A dial plan is a named set of one or more number-string translation rules that translate called number-strings into alternate (desired) formats.

Teams dial plans ensure that numbers originating with various user-input formats are translated into standardized formats (typically E.164) for the purposes of matching called numbers to resources that the user is authorized to use, and for routing the calls.

The rules within a dial plan are known as normalization rules, and their purpose is to support users dialing numbers in a variety of patterns, and resolving their nonstandard number format into an expected, standardized format.

A normalization rule in one dial plan can be translated differently than a normalization rule in another dial plan, so depending on which dial plan is assigned to a given user, a dialed number may be translated and routed differently.

Normalization rules and examples are addressed in a later article; see Normalization rules.

Dial plan scopes and a user's effective dial plan

Outbound telephone calls from Teams users are routed based on a series of assigned configuration items, including their assigned dial plan.

Teams supports three distinct scopes of dial plans, outlined in the following table:

A user is always assigned to the service dial plan and a user is always assigned to either a tenant dial plan or a user dial plan, but can't be assigned to a tenant dial plan and user dial plan at the same time.

In the priority of processing normalization rules for a dialed number, the user dial plan takes precedence over the tenant (Global) dial plan, and the tenant dial plan takes precedence over the service dial plan.

Teams applies a hierarchy of the three dial plan scopes, and each Teams user inherits what's known as their "effective" dial plan.

The possible effective dial plans for users are outlined in the following table:

You can't change the service dial plan for the Teams Phone service, but you can edit the tenant (Global) dial plan or you can create custom user dial plans, which augment the service dial plan. As clients are provisioned, they obtain an "effective dial plan," which is a combination of the service dial plan for their country or region and the user's assigned dial plan. It's not necessary to define all normalization rules in the tenant or user dial plans as the rules might already exist in the service dial plan for the country/region.

Clients get the appropriate dial plan through provisioning settings that are automatically provided when users sign in to Teams. As an admin, you can manage and assign dial plan scope levels by using the Microsoft Teams admin center or Remote PowerShell. For more information, see Create and manage dial plans.

Planning for tenant dial plans

To plan custom dial plans, follow these steps:

• Step 1 Decide whether a custom dial plan is needed to enhance the user dialing experience. Typically, the need for one would be to support non-E.164 dialing, such as extensions or abbreviated national dialing.

• Step 2 Determine whether tenant global or tenant user scoped dial plans are needed, or both. User scoped dial plans are needed if users have different local dialing requirements.

• Step 3 Identify valid number patterns for each required dial plan. Only the number patterns that aren't defined in the service level country/region dial plans are required.

• Step 4 Develop an organization-wide scheme for naming dial plans. Adopting a standard naming scheme assures consistency across an organization and makes maintenance and updates easier.

Dial plans and routing considerations

There can be a maximum of 1,000 tenant dial plans per tenant.

Number normalization in user effective dial plans behaves different than number translation in route-based rules. For example,

• The Teams client normalizes numbers for all outbound calls, including calls placed from call history or from telephone-number links, based on user effective dial plans.

To learn more about route-based translation rules, see Translate phone numbers in Direct Routing.

Number lookup for inbound calls

Routing inbound calls to users is supported when all Teams user and resource accounts have unique number and extension values assigned for their telephone number.

The unique values of the user's telephone number can have two parts, as follows:

• Number - For inbound calls to resolve to users with Microsoft Calling Plan and Operator Connect solutions, the number value is designated as a number in E.164 format. For example, +14255551212. For Direct Routing solutions, the number value is designated as a number between 3 and 38 digits without common symbols.

• Extension - added to the number and separated by the ";ext=" delimiter (case insensitive), between 1 and 12 digits. For example, +14255551212**;ext=12345**

An extension isn't necessary; only a unique number is required for Reverse Number Lookup. If multiple end-users are sharing a single, main number, and a Teams Shared Calling policy isn't being used, then unique extensions must be assigned to each user. Otherwise, extensions aren't required or recommended.

For example, assume that a user is assigned the phone number +14255551212. If a PSTN caller dialed +14255551212, RNL finds the number-string match, and the call is connected to that user.

If the user is assigned a phone number with an extension, +14255551212;ext=12345, the inbound dialed number must include the extension for matching to work.

If the dialed number isn't matched, either because the number isn't assigned to an account or the number dialed doesn't exactly match any number string assigned to an account, the call fails to route or is routed according to unassigned number routing, if configured.

When you have a Direct Routing deployment with no digit translation configured on the SBC, and if the calls aren't presenting numbers in the format that you designated for your users, use a route-based number translation rule to normalize the inbound called number to a format that matches what is assigned to your users. See Translate phone numbers in Direct Routing.

If you want internal users who call a phone number that is assigned to a resource account, to bypass the Reverse Number Lookup logic and route the call externally through the PSTN instead of routing to the resource account, you can enable the skip RNL option for the phone number assignment using the Set-CsPhoneNumberAssignment PowerShell cmdlet with -ReverseNumberLookup. For more information, see Set-CsPhoneNumberAssignment and Get-CsPhoneNumberAssignment.

User dial plans with Calling Plans and Operator Connect

When you're deploying Calling Plan, Operator Connect, or Teams Phone Mobile for your PSTN connectivity, dial plans and voice routing policies are preconfigured at the service level and administration isn't necessary.

User dial plans with Direct Routing or extension dialing

If you deploy Direct Routing for your PSTN connectivity or are supporting extension dialing requirements, more steps are required to configure call routing.

When you're deploying Direct Routing or extension dialing, the user's effective dial plan provides admins with the ability to configure a set of rules that help translate the user's dialed digits into a number that is resolved to a destination where Teams can route the call.

• You must configure call routing by specifying the voice routes and assigning voice routing policies to users. You can configure number translation rules at the route level to ensure interoperability with Session Border Controllers (SBCs). For more information, see Configure voice routing for Direct Routing, Manage voice routing policies, and Translate phone numbers.

• You can assign a Direct Routing online voice routing policy to Calling Plan and Operator Connect users and may want to do this, for example, to enable users to dial in to a call center that is directly connected with Direct Routing.

Direct Routing online voice-routing policy with Calling Plan

If a user has a Calling Plan license, that user’s outgoing calls are automatically routed through the Microsoft Calling Plan PSTN infrastructure. If you configure and assign a Direct Routing online voice-routing policy to the user, Teams checks the user’s outgoing calls against the Direct Routing online voice-routing policy to determine whether their dialed number matches a number-pattern that you've defined in the online voice-routing policy. If there’s a match, the call is routed through the Direct Routing route. If there’s no match, the call is routed through the Calling Plan PSTN infrastructure.

For more information, see Direct Routing voice routing policy considerations.

Related topics

Create and manage dial plans

Normalization rules

Direct Routing trunk translation rules

Route calls to unassigned numbers

PSTN connectivity options