Microsoft Teams Calling

Setting up Microsoft Teams Calling is more difficult than a SIP trunk for instance and requires a considerable amount of coordination with your IT Provider. Its a multi step process so takes time.

The technical name for Microsoft Teams Calling is Direct Routing. Direct Routing connects Microsoft Teams to the public telephone network (PSTN), allowing you to make and receive real phone calls from Teams. It transforms Teams from just a collaboration tool into a complete business phone system.

A channel in the context of Microsoft Teams Calling trunks is essentially a single, concurrent call path that allows one call (inbound or outbound) to be active at any given time.

Think of a Teams Calling channel like a traditional telephone line: if you have 10 lines, you can have 10 people talking simultaneously. Similarly, if you have 10 SIP channels, you can support 10 concurrent calls.

Determining the required number of channels you require is a bit trickier and depends on your business's call volume and usage patterns. The professional and accurate method uses the Busy Hour Call Attempts (BHCA) Metric to calculate a factor known as Erlang B. A simpler rule of thumb for many small to mid-sized offices is as follows:

• Typical Office (General employees, light phone use) - 1 channel for every 4-5 phones
• Moderate/Sales Team (Regular, consistent phone use) - 1 channel for every 3 phones
• Call Center/High-Volume (Agents on the phone all day) - 1 channel for every 2 phones

Note that its always worthwhile to give a 20-30% buffer for peak times.

When you don't have enough channels, users will frequently experience busy signals or failed calls when trying to make or receive external phone calls.

Here are the key signs that you need more channels:

Too Many Busy Signals: When someone tries to call out from Teams, they get a fast, repeating busy tone right away, or the call fails with an error message, even though the person they're calling isn't busy. This happens because all your lines are currently tied up with other people's conversations, so there's no channel left for this new call.

Incoming Callers Can't Get Through: People calling into your organisation frequently complain that they get a busy signal or the call simply drops/fails before it even starts ringing anyone. This is because your system can't bring the incoming call in because there are no channels free to accept it.

Problems Happen at the Same Time: These problems only seem to happen during peak business times. This is when the maximum number of people are trying to use the phones, pushing you over your limit.

There is no need to panic however as this is an easy problem to fix. Additional channels can be quickly added to the trunk alleviating the issue.

Microsoft Calling Plans are provided directly by Microsoft in collaboration with other telco providers at usually higher costs. Direct Routing lets you choose your own provider such as IPC Solutions to provide this functionality.

Absolutely! We can port your existing phone numbers to our SIP Trunk service from any provider. The process can take up to 6 weeks if its a complex number port but you can use the new SIP Trunk, showing the correct Caller ID number during this period.

Note that every Teams user needs a phone number so you may need to add some new numbers if migrating from a system that did not provision numbers for all users.

You need Microsoft Teams Phone Standard licenses which would be provisioned by your IT Provider. This is included in Microsoft 365 E5 or can be purchased as an add-on to other Microsoft 365 plans.

We offer configuration assistance to your IT Providers to set up the new Teams Calling trunk on your Teams tenancy.

Note that we cannot support your Teams tenancy in any way and the expectation is that your IT would contact us after initial analysis of a problem with the service.