📞 Microsoft Teams: collaboration platform with a telephony add-on
A workplace collaboration platform built into Microsoft 365. Telephony is a separate Teams Phone add-on licence, and in Luxembourg the PSTN path runs through a local operator via Operator Connect or Direct Routing. Calling Plans (Microsoft's own direct PSTN service) are not available for Luxembourg numbers.
⏱ 10 min read · 🌍 UC platform · 📅 Updated April 2026 · 🔗 microsoft.com/microsoft-teams
🏢 Who Microsoft Teams is
Microsoft Teams is the collaboration platform built into Microsoft 365, with around 300 million monthly active users worldwide. It covers chat, video meetings, file collaboration, and application integration. Teams is not, on its own, a phone system. Telephony is a separate add-on called Teams Phone, which plugs Teams into the public phone network and gives users a business number, inbound and outbound calling, and voicemail inside the Teams client.
Teams Phone has three possible paths to the public phone network: Microsoft Calling Plans (Microsoft acts as the operator), Operator Connect (a certified local operator handles calling inside the Microsoft admin centre), and Direct Routing (a Session Border Controller, or SBC, connects Teams to any SIP-capable operator). Calling Plans are not available for Luxembourg numbers. In practice, Luxembourg deployments use Operator Connect (Cegecom is the certified Luxembourg Operator Connect provider) or Direct Routing (DEEP Telecom and Mixvoip both offer Direct Routing paths for Luxembourg, as does Proximus NXT with their own Teams Voice branding). Full disclosure: this site is maintained by a team connected to Mixvoip and Voxbi, and Mixvoip offers Direct Routing SBC connectivity for Luxembourg Teams Phone deployments.
📦 What Teams Phone offers
Teams Phone is the telephony layer bolted onto the Microsoft 365 stack. The main components a Luxembourg business encounters:
💬 Calling inside the Teams client
Users make and receive business calls directly in the Teams desktop, mobile, or web client. Contact lookup pulls from Microsoft 365 directory, call history is synced across devices, and voicemail transcription appears in the Teams UI. For organisations already working in Teams every day, telephony becomes one more tab rather than a separate application.
🎯 Three PSTN paths, two practical in Luxembourg
Microsoft Calling Plans (where Microsoft supplies the phone numbers and minutes directly) are not available for Luxembourg numbers. That leaves Operator Connect and Direct Routing. With Operator Connect, a certified operator provisions the service inside the Microsoft 365 admin centre with minimal configuration. With Direct Routing, a Session Border Controller bridges Teams to any SIP-capable operator, which gives flexibility at the cost of additional setup and ongoing SBC management.
💶 Three cost layers
The commercial model stacks three components: a Microsoft 365 licence (typically Business Basic from around 6 EUR per user per month, or higher tiers), the Teams Phone add-on (approximately 8 to 10 EUR per user per month), and PSTN fees from the Luxembourg operator handling the calling path. Some Microsoft 365 E-tier enterprise licences bundle Teams Phone, which reduces the stack to two layers. The total lands in a range comparable to a dedicated Cloud PBX, depending on headcount, call volume, and which Microsoft 365 tier is already in place.
📊 Admin centre management with basic call analytics
Teams Phone configuration lives in the Microsoft Teams admin centre, which is a subset of the broader Microsoft 365 admin environment. Call queues, auto-attendants, and basic reporting are available. Advanced telephony features (live wallboards, detailed agent-level analytics, complex routing logic, deep contact-centre capability) are less developed than on a purpose-built PBX, though Microsoft continues to expand the feature set and third-party contact-centre products integrate with Teams natively.
🔗 Deep Microsoft 365 integration
For organisations already standardised on Microsoft 365, Teams Phone inherits single sign-on, directory integration, compliance and retention policies, Outlook contact sync, and Graph API access. Calls can be associated with Outlook calendar events, Planner tasks, and SharePoint documents. This is the main reason Teams Phone is adopted: not telephony excellence, but environmental continuity.
⚖️ Quick compare with two UC rivals
Microsoft Teams is a UC platform with a telephony add-on. This page compares it against two products a Luxembourg business might shortlist alongside it, using UC platform criteria.
🌐 Microsoft Teams
UC platform with Teams Phone · this page
You are here
Telephony add-on required: yes, Teams Phone licence
Public pricing: yes (~8-10 EUR/user/month add-on)
PSTN options: Operator Connect, Direct Routing (no Calling Plans in LU)
SIP trunk integration: Direct Routing via SBC
Deployment complexity: M365 admin + operator setup
Target segment: mid-market and enterprise
☁️ Voxbi
Managed Cloud PBX
Telephony add-on required: no, telephony is the core product
Public pricing: yes, per user per month
PSTN options: Luxembourg numbers included
SIP trunk integration: included, not separately configured
Deployment complexity: self-serve portal, direct from Mixvoip
Target segment: SME to mid-market
🔴 Cisco Webex
UC platform with Webex Calling
Telephony add-on required: yes, Webex Calling licence
Public pricing: yes, per user per month tiers
PSTN options: Cloud Connect, Local Gateway, Cisco Calling Plans (limited regions)
SIP trunk integration: Local Gateway SBC
Deployment complexity: Webex Control Hub + partner-led
Target segment: mid-market and enterprise
Comparison reflects public information. Sources linked from each provider page. Not a ranking.
👥 Typical client profiles
Teams Phone lands in organisations where Microsoft 365 is already the environment, and where telephony is a feature addition rather than a standalone procurement. Four common profiles:
🏢 The Microsoft 365 E5 enterprise
A mid-market or large organisation on Microsoft 365 E5 licences, where Teams Phone is already included. Adding telephony is a matter of enabling the service and setting up an Operator Connect or Direct Routing relationship. The per-user cost is already paid as part of E5, which makes Teams Phone economically attractive regardless of its telephony feature depth.
💼 The Business Premium organisation adding telephony
A smaller organisation on Microsoft 365 Business Premium that wants one vendor for productivity and communication. Teams Phone is added as a separate per-user licence, paired with a Luxembourg Operator Connect or Direct Routing path. The driver is environmental consolidation rather than telephony preference.
🏦 The regulated industry with compliance dependencies
A bank, insurer, or professional services firm where data governance, retention policies, eDiscovery, and compliance audits already run through Microsoft 365. Keeping voice records in the same compliance and retention framework as chat and email simplifies audit and regulatory reporting.
🌍 The multi-country enterprise standardising on one platform
An organisation with offices in multiple countries that wants one telephony platform across all locations, with local PSTN provided per country. Teams Phone with Operator Connect covers this pattern well, because the Microsoft admin centre manages the global user base while local operators supply country-specific numbers.
🎯 Where Teams stands apart
Three positioning points worth weighing before choosing Teams Phone over a dedicated Cloud PBX.
🔗 Native Microsoft 365 integration
For organisations already standardised on Microsoft 365, Teams Phone is the only option that sits natively inside the same identity, directory, and compliance stack. Single sign-on, directory sync, retention policies, and cross-application workflows all work without configuration. A dedicated PBX alongside Microsoft 365 can integrate with single sign-on and calendar, but the integration is an additional layer rather than a default.
📞 Telephony as an add-on, not the core product
Teams Phone is a feature of a collaboration platform. The administration UI, the routing depth, the contact-centre capability, and the call analytics all reflect that positioning. For businesses whose telephony is straightforward (internal calls, simple IVR, basic queues), this is rarely a limitation. For front-desk-heavy operations, contact centres, or businesses that need detailed call routing and analytics, a purpose-built PBX often fits the telephony use case better.
🇱🇺 Luxembourg PSTN requires a local operator
Microsoft Calling Plans are not available for Luxembourg numbers. Any Teams Phone deployment in Luxembourg means at least two vendors: Microsoft for the platform, plus a local operator for the PSTN path. With Operator Connect the operator setup is relatively light; with Direct Routing it involves an SBC and more ongoing configuration. A dedicated Luxembourg Cloud PBX includes the PSTN path as part of the service, which reduces vendor count and consolidates the support relationship.
📚 Terms you can look up
Not sure what something on this page means? The pbx.lu glossary explains each in plain language.
🧩 Decision tree
Two honest recommendations based on business profile.
✅ Choose Teams Phone if
- Microsoft 365 is already the daily environment and compliance stack
- Your organisation is on E5 or willing to add the Teams Phone add-on to Business Premium
- Telephony needs are straightforward and advanced call centre features are not required
- You have IT capacity to manage a multi-vendor setup (Microsoft + Luxembourg operator)
🟡 Look elsewhere if
- Telephony is a front-line business function (reception, contact centre, sales queues)
- You want one Luxembourg provider for numbers, PBX, and support on one invoice
- You do not already use Microsoft 365, and adding it just for telephony is not economic
- Advanced call routing, wallboards, or agent-level analytics are core requirements
🔎 Other providers worth considering
If Teams Phone is not quite the right fit, these are the logical next pages to check.
Same category · other PBX products and UC platforms
🟤 Starface
German-engineered PBX, DACH IT partner network, native Teams integration
Different category · Luxembourg operators for Teams Phone
🔵 DEEP Telecom
POST Luxembourg's B2B brand, Direct Routing path for Teams Phone
❓ Common questions
Do I need Microsoft 365 to use Teams Phone?
Yes. Teams Phone is an add-on to Microsoft 365. A business cannot use Teams Phone without an active Microsoft 365 Business or Enterprise subscription that covers Teams. For organisations not already on Microsoft 365, the underlying M365 licence is a significant base cost that sits underneath the telephony layer.
Can Teams Phone work in Luxembourg without a local operator?
No. Microsoft Calling Plans, where Microsoft itself supplies phone numbers and minutes, are not available for Luxembourg numbers. Any Luxembourg Teams Phone deployment needs a local operator: Cegecom via Operator Connect, or DEEP Telecom, Mixvoip, or Proximus NXT via Direct Routing. The operator relationship is separate from the Microsoft licensing.
What is the difference between Operator Connect and Direct Routing?
Both paths connect Teams to a local operator for PSTN calling. Operator Connect is a managed, simplified method where the certified operator provisions the connection inside the Microsoft 365 admin centre with minimal configuration. Direct Routing uses a Session Border Controller (SBC) to bridge Teams to any SIP-capable operator, which offers more flexibility but requires more ongoing technical management. In Luxembourg, Cegecom is the Operator Connect provider; DEEP Telecom, Mixvoip, and Proximus NXT offer Direct Routing paths.
Can a business use both Teams and a dedicated Cloud PBX at the same time?
Yes. Many Luxembourg organisations use Teams for internal chat, meetings, and documents while running a dedicated Cloud PBX for their phone lines, extensions, and IVR. The two systems coexist: SSO works across both, and the PBX exposes an integration into Teams (via SBC routing or a connector) if users want click-to-dial from the Teams client. This approach avoids Microsoft dependency for telephony while keeping the collaboration tools the team already uses.
Is Teams Phone suitable for a small business in Luxembourg?
It depends on two factors: whether the business is already on Microsoft 365, and how telephony-intensive the operation is. An existing Microsoft 365 Business Premium customer adding Teams Phone gets consolidated licensing and one identity system; a small business not on Microsoft 365 faces a larger base cost before telephony even starts. For telephony-light operations the answer is often yes; for reception-heavy or customer-service operations, a purpose-built Cloud PBX usually delivers more telephony depth.
What is a Session Border Controller (SBC)?
A Session Border Controller is a network device (hardware or software) that sits between a SIP network and an external network, handling signalling translation, security, call routing, and media processing. In a Direct Routing setup, the SBC bridges the Teams environment and the Luxembourg operator's SIP network. Some operators provide the SBC as a managed service; others expect the customer or integrator to supply and manage it.
How does Teams Phone pricing compare to a dedicated Cloud PBX?
Teams Phone pricing stacks three components: the Microsoft 365 base licence, the Teams Phone add-on, and PSTN fees from the Luxembourg operator. A dedicated Cloud PBX usually consolidates the phone system and local calling into one monthly per-user price. The total Teams Phone cost in Luxembourg lands in a range broadly comparable to a dedicated Cloud PBX, depending on which Microsoft 365 tier is already paid for, the headcount, and the chosen operator's PSTN pricing model.
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