As a pioneer of BYOT – Bring Your Own Trunk – Microsoft is empowering customers to get the most of their corporate voice solutions with Microsoft Teams Direct Routing. Adaptable and scalable, Direct Routing gives enterprise companies the opportunity to use their preferred SIP providers for calling in Teams. Given that Skype for Business will soon be phased out by Microsoft, it’s more important than ever to start preparing your organisation for the future of voice communication. Read our guide below for everything you need to know to get started with your deployment:
The Enterprise Model
If you’re tied to an existing phone system or other on-premises hardware, then you will likely follow the enterprise model. In this case, the SBC is located on the customer premise and is connected to a single Office 365 tenant. For this model, you will need the following:
Licensing
All companies must have:
- An Office 365 enterprise subscription either through an E1, E3, or E5 license
- A Microsoft Audio Conferencing licence, which can be found as part of the E5 license or as an add-on for the E3 license. This is required in order to add external participants to scheduled meetings
- A phone system licence, which can be fulfilled either through the E3 or E5 license
- Note that Direct Routing also supports users with the additional license for the Microsoft Calling Plan
Infrastructure
There are several infrastructure to-dos all organisations need to follow, including:
- Finding Qualified SBCs: All organisations will need a supported SBC. As of now, the qualified SBC vendors are Audiocodes, Ribbon Communications, Thinktel, Oracle, and TE-Systems
- Connecting the SBC: In order to connect the SBC to the Microsoft Teams SIP proxy, companies will need to have:
- A SIP signalling port
- A fully qualified domain name (FQDN). This must come from one of the registered domains in the organisation’s Office 365 tenant. Examples can be found here
- A public trusted certificate for the SBC, which can support a wildcard or a SAN certificate. Microsoft recommends requesting the certificate by generating a certification signing request (CSR). Importantly, the certificate needs to be generated by one of a select group of root certificate authorities. You can find the list
- A public IP address for the SBC. It is recommended to only open this IP address to Teams Transport Relays
- A public DNS entry for the SBC, which will map the SBC FQDN to the public IP address
- Connecting the SIP trunk or legacy PRI: Organisations will need a telephony trunk that can connect to the SBC
The Carrier Hosting Model
If you’re not tied to an existing phone system, many experts recommend using the carrier hosting model. In this model, the customer picks the provider of their choice to host the Direct Routing SBC and to handle telephony services. Customers will use a carrier’s SBC, which is paired with their Office 365 domain and then tied to multiple Office 365 tenants via subdomains. Here are some key facts about the carrier hosting model:
- Since calls are not routed based on DID, each customer instead gets a unique SBC FQDN as a subdomain to the carrier base domain, which is then added as a domain in the customer’s tenant. Notably, all customers will have the same SBC
- Only a wildcard certificate covering the carrier base domain is needed, so it is not necessary to have customer-specific certificates on the SBC
- For each carrier-hosted SBC, organisations will only need to set up a configuration once per tenant. This will cover all SIP domains within that Office 365 tenant
Licensing
When using a third-party carrier, you will need the following:
- Along with the Teams licenses, you will need a subscription from your carrier of choice. When picking your carrier, you will be able to choose from an array of billing options, such as flat rate, pay-as-you-go, toll-free, or an option bundled with other subscriptions.
Infrastructure
You will also need:
Gary Forrest[/caption]
