Bring your own carrier (BYOC) is an arrangement in which a cloud communications platform, such as a UCaaS service, Microsoft Teams Phone or a cloud contact center, connects to a phone carrier you choose for calls to and from the public phone network, instead of using the platform’s own bundled calling service. You keep the platform for its features and buy phone numbers and calling minutes from your carrier, usually as SIP trunks. Platforms use different names for it, and support varies by platform, plan and country.
At a glance
- BYOC separates the communications platform from the carrier that connects it to the phone network.
- The connection is usually SIP trunking, often through a session border controller run by you, the carrier or a partner.
- It can lower calling costs, keep existing numbers and rates, and extend coverage to more countries.
- It adds components and parties, so support responsibilities need to be agreed up front.
- Microsoft Teams Direct Routing is a well-known example; many contact center platforms offer their own BYOC options.
What problem it solves
Cloud phone and contact center platforms often bundle calling: numbers, minutes and the connection to the phone network come from the platform vendor. That is simple, but it may not suit everyone. The vendor’s rates may be higher than an organization’s negotiated carrier rates, especially for contact centers with heavy inbound or international traffic. The vendor may not offer numbers in every country. And moving numbers to the platform ties them to that vendor.
BYOC lets an organization keep a carrier relationship it already has, or pick a carrier for price, coverage or quality, while still using the cloud platform. It can also add resilience by using more than one carrier, and can keep other systems, such as an existing PBX or contact center, on the same carrier during a migration.
How it works
Carrier service. You buy SIP trunks or an equivalent service from a carrier, including phone numbers and calling. Existing numbers can usually be moved to that carrier with local number portability (LNP).
Connection to the platform. The carrier connects to the platform in one of several ways, depending on what the platform supports:
- Through a session border controller (SBC) you or a partner operate, which links the platform and the carrier.
- Through a direct connection between the carrier and the platform, often built on carrier interconnection and often limited to carriers the platform has certified.
- Through a managed service where a partner runs the SBC and carrier connection for you.
Configuration. In the platform, administrators assign the carrier’s numbers to users, queues or call flows and set routing rules for outbound calls.
Emergency calling and caller ID. With BYOC, 911 routing and location often depend on settings in the platform, the SBC and the carrier together. In the US, carriers are required to authenticate caller ID on IP calls, so confirm which party signs your calls. Requirements differ by country.
When it matters for buyers
- When moving to Teams Phone, UCaaS or a cloud contact center and deciding between the bundled calling plan and your own carrier.
- When calling costs are a large share of the bill, such as in high-volume contact centers.
- When operating in countries the platform’s own calling service doesn’t cover.
- When renewing carrier or platform contracts, since BYOC lets you negotiate them separately.
- When keeping legacy systems connected to the same carrier during a migration.
Questions to ask vendors
- Does your platform support BYOC in our countries, and with which carriers or connection methods?
- Do we need our own SBC, or does the carrier or a partner provide the connection?
- What platform licenses or fees apply when we bring our own carrier?
- Who leads troubleshooting when calls fail, and what data will each party share?
- How are 911 calls routed and located for users and agents on BYOC?
- Can we use more than one carrier, and how does failover work between them?
- How will our numbers move, and what happens to them if we later leave the platform or the carrier?
How it differs from SIP trunking
SIP trunking is the carrier service: numbers and a connection to the phone network over IP. BYOC is the arrangement of using that service with a cloud platform instead of the platform’s own calling. Most BYOC setups use SIP trunks, but SIP trunks are also used without any cloud platform, for example to connect an on-premises phone system. Microsoft Teams Direct Routing is one platform’s version of BYOC.
For help deciding between bundled calling and your own carrier in Teams, see our Microsoft Teams PSTN connectivity solution page.