Is this what you are using to communicate & collaborate?
External Calls on a phone system and Internal Calls on Teams?
Why not use Teams as your deskphone?
If you are using

you HAVE to watch this video to see what is possible.

ADDING VOICE USING DIRECT ROUTING
Direct Routing enables Microsoft Teams to operate as a full PBX phone system by connecting Teams to the telecom carrier of your choice instead of using Microsoft Calling Plans. This provides greater flexibility, control, and potential cost savings.
Key Benefits:
Keep existing business phone numbers
Choose preferred carriers based on cost, coverage, or features
Access full enterprise calling features (auto attendants, call queues, voicemail, conferencing, forwarding)
Scalable and secure for organizations of any size
Seamless integration with Teams chat, meetings, and file sharing
Best Used When:
You want more control over telecom providers or costs
You have existing carrier contracts or legacy PBX systems
You require advanced calling capabilities
Implementation Requirement:
Direct Routing requires a certified Session Border Controller (SBC) to securely connect your telecom carrier to Microsoft Teams.

There are multiple options available we can show you.
Companies leveraging the the market leading Microsoft Teams ecosystem have begun embracing the technology not just as a tool for collaboration but also as a comprehensive suite for various forms of communication.
Thanks to Microsoft’s extensive partner network, organizations can leverage integrations and apps to expand the functionality of their platform.
Unifying customer experience teams and delivering powerful omnichannel interactions to clients is possible through the right integrations.
In this article, we’re looking at some of the top certified integrations for Microsoft Teams, which transform the ecosystem into a powerful contact center solution.
NICE CXone for Microsoft Teams is a pre-built unified communications and contact center integration that powers company-wide collaboration for faster service.
The CXone Agent—embedded seamlessly within Teams— provides full contact center controls and synchronizes Teams contacts and presence information, for one-click access to experts across your organization.
With Zoom's latest integration for Microsoft Teams, it’s easy to access Zoom from inside the Teams app with a dedicated page for starting and scheduling your Zoom Meetings.
Zoom's Microsoft Teams integration allows you to start an instant meeting, join a scheduled meeting, or make Zoom Phone call through Bots commands. Meetings created in Teams appear in your Zoom account.
8x8 Voice for Teams APP
Moving all voice, SMS/MMS, and faxing in to Teams using
8x8 Voice for Teams can be an easy transition for Teams users.
From the app you can make & receive calls, send & receive
SMS and faxes using existing work & fax numbers within Teams.
The app gives users access their 8x8 account settings including your voicemail, call forwarding, and the ability to
log in or out of your assigned call queues.