A Guide to Direct Routing

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We’re assuming by reading this article that you’ll already know what Microsoft Teams is, but for the uninitiated: it is one of the fastest growing business products in the world, providing internal communication and meetings, document management and app integrations. With Microsoft’s announcement of phone capabilities for the platform, there has been a growing buzz about a key technology to allow businesses to adopt this: Direct Routing.

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What is Direct Routing?

“Direct Routing” refers to the process of routing Microsoft Teams to the PSTN (traditional phone network).

Although Teams is mainly used as an internal communications tool, Microsoft has developed a way for the platform to be used as a fully fledged business phone system (PBX). There are basically two ways of doing this:

Using a Microsoft Calling Plan

Created and maintained by Microsoft in the cloud, these plans essentially turn Teams into a fairly light-touch hosted PBX, tightly integrated with the rest of Teams’ functionality. This option is expensive and only available (at time of writing) in a few territories. Porting numbers can also be confusing and time consuming, with no dedicated contact to help with the process.

Using Direct Routing

Direct Routing allows you to connect up Teams to a range of telephony providers (like Gradwell). This means being able to take advantage of cheaper call rates, more flexibility and better support.

Direct Routing is seen as extremely attractive by a variety of businesses as it gives them the true flexibility of choosing their own telephony provider, but as direct routing is through certified Microsoft Partners, retain a verified integration with the Teams platform.

How does Direct Routing work?

Direct Routing works by combining the Teams system to the PSTN using two key elements: a Session Border Controller and SIP Trunks.

Session Border Controller (SBC)

Often described as a “firewall for VoIP”, these are used at the “borders” between different networks to make sure data is transferred properly between them, as well as providing a layer of security and protection from attacks and breaches. SBCs were traditionally located on premise, but increasingly are cloud-hosted, allowing a much higher level of flexibility and reliability together with lower up-front costs.

SIP Trunks

These are connections between a business phone system, the internet and the traditional phone network (PSTN). SIP Trunks are an essential component for connecting any PBX to the PSTN and a genuine alternative to using a hosted “all-in-one” system, like Gradwell’s own: Wave.

Note that some providers only offer an SBC without SIP Trunks. This means you’ll need to find a separate supplier to provide the trunks, adding complexity and cost.


Who is Direct Routing For?

Direct Routing is primarily designed for organisations set on using Teams as a PBX, but looking for more flexibility than Microsoft’s pre-set calling plans.

Any business that matches one of the following criteria is a strong candidate for considering direct routing:

Is a strong user of Teams

This one is obvious, but any business that is deeply embedded in using Microsoft Teams for internal communications can more easily use the platform for their external communication too. This also means less of a need for a separate PBX (and all the costs entailed) together with better integration between systems.

Limited in-house expertise

Any business with a smaller IT team (or none at all) may want external support when considering using Teams as a PBX. Experienced providers (like Gradwell) can give step by step account management and essentially install Direct Routing and any associated other equipment for you.

Wants more flexibility than Microsoft calling

Microsoft’s own calling plan doesn’t offer much flexibility with absolutely no room for negotiation. Using Direct Routing, particularly for any business that makes a reasonable amount of outbound calls (and even more so if they are international) becomes the obvious choice.

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How much does it cost?

This hugely depends on the provider, individual business circumstances and more, so an exact estimation is impossible, but direct routing will almost always mean a much cheaper recurring price per user per month than Microsoft’s own Calling Plans.

What are the benefits?

Choosing Direct Routing has its own particular benefits including:

True Unified Communications

The idea of using Teams as a PBX is a huge step forward for businesses who like the idea of Unified Communications – combining all of their internal and external communications into one tightly-knit system.

Choose your own provider

Direct Routing means third party integration, but that can be a positive. Choosing the right provider can save you huge amounts of upfront and ongoing fees, and gain a large amount of expertise and reliability.

Port your numbers

Switching to Teams as a PBX doesn’t mean losing your old numbers. Keep your existing ones alongside any new DDIs you need.

How does the setup process work?

This depends on the provider, but at Gradwell, this is broadly our approach. All of these steps are done under the watchful eye of our trained support and onboarding teams and require no in-house expertise on the customer’s side.

Number porting requested and new numbers ordered

The customer simply requests new numbers from the provider and/or ports their existing ones over. Depending on the provider (and numbers), this process can take anywhere from less than a day to a couple of weeks.

Customer shares Teams and IP details with Provider

Sharing Microsoft Teams and IP details with the provider allows them to check their Teams profile, set up SIP Trunks and an SBC.

Provider sets up SIP trunks and SBC

This is self explanatory; the Session Border Controller and Trunks are the foundations of direct routing. This should take less than a day for a provider that can set up both SBCs and SIP Trunks.

Provider works with customer to test calling and numbers

Testing inbound and outbound calls is obviously crucial before setting live. We work with our customers to make sure calls are completed and with high-quality audio from a variety of sources.

Set live and training staff

The best bit: changing your PBX over to Teams! It’s important to make sure you have a plan to train your colleagues on how to use Teams as a phone system, and to make sure any setup from your existing system (hunt groups, calling behaviour etc) is reflected on your Teams instance.

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