01
Carrier lock-in
Bundled calling options may not match existing contracts, regions or pricing strategies.
Microsoft Teams Direct Routing
Connect Microsoft Teams Phone without giving up carrier, routing or security control.
M5 Technologies helps enterprises, service providers, government and critical infrastructure operators connect Teams Phone to SIP trunks, carriers, PBXs and legacy systems using Microsoft-certified Sentinel SBC architecture.
Carrier flexibilityKeep preferred SIP trunks and telecom contracts.
Hybrid migrationConnect Teams with PBXs and legacy voice systems.
SBC-grade securityApply TLS, SRTP, normalization and topology hiding.
High availabilityDesign redundant trunks, SBCs and recovery paths.
How Teams Direct Routing worksTeams Phone → Sentinel SBC → enterprise voice network
Microsoft-certified SBC
Microsoft cloud
Teams usersTeams PhoneCalling policiesCollaboration
↓
M5 Sentinel SBC layer
Sentinel CSSentinel 100Sentinel 400TLS/SRTPSIP policy
↓
Enterprise voice network
SIP carriersPBXPSTNContact centerEmergency calling
ControlChoose carriers and routing.
SecurityProtect the SIP edge.
MigrationMove users in phases.
Microsoft certifiedSentinel SBC architecture for Teams Direct Routing.
Virtual or applianceChoose Sentinel CS, Sentinel 100 or Sentinel 400.
Hybrid voiceConnect Teams, PBX, gateways, carriers and analog services.
Secure SIPTLS, SRTP, topology hiding, normalization and routing policy.
The customer problem
Teams migration becomes difficult when cloud voice meets real-world telecom infrastructure.
Most organizations already have carriers, DID inventories, PBXs, contact centers, analog devices, emergency calling and regional routing requirements that cannot be replaced in one step.
02
PBX coexistence
Teams must often work beside existing PBXs, contact centers and branch systems.
03
SIP interoperability
Teams, carriers and legacy systems may require signaling normalization and routing control.
04
Continuity risk
Carrier, cloud, SBC or site failures can interrupt enterprise calling.
Customer impact: without the right SBC architecture, Teams Voice can create rigid carrier dependencies, failed call flows, weak disaster recovery and a high-risk migration.
How M5 resolves the use case
Create one controlled voice layer between Teams, carriers and existing systems.
Sentinel SBCs provide the security, routing and interoperability controls required to move to Teams Voice without abandoning enterprise telecom requirements.
Secure the Teams edge
Control SIP signaling and media between Microsoft Teams and external voice networks.
- TLS and SRTP support
- Topology hiding
- SIP normalization
Connect enterprise voice
Integrate carriers, PBXs, contact centers, gateways and emergency services.
- Carrier and trunk choice
- Hybrid PBX coexistence
- Central routing policy
Migrate with continuity
Move users and sites in phases while validating call flows and recovery paths.
- High availability
- Disaster recovery
- Phased adoption
Microsoft Teams PhoneUsers, policies and cloud collaboration
→
Sentinel SBCSecurity, routing and SIP interoperability
→
Enterprise systemsPBX, contact center, gateways and analog services
→
Carrier & PSTNSIP trunks, numbering and emergency calling
Teams voice comparison
Direct Routing vs Calling Plans vs Operator Connect.
The right model depends on carrier control, integration complexity, geographic reach, operational ownership and resilience requirements.
| Criteria | Microsoft Calling Plans | Operator Connect | M5 Direct Routing |
|---|---|---|---|
| Carrier choice | Limited Uses Microsoft-provided calling plans where available. | Managed selection Choose from participating operators. | High flexibility Use preferred SIP carriers and existing contracts. |
| Customer-controlled SBC | No | Usually operator controlled | Yes Customer, integrator or provider can control the SBC architecture. |
| PBX coexistence | Limited for complex environments | Depends on operator capabilities | Strong Designed for Teams, PBX, gateway and carrier coexistence. |
| Legacy gateway integration | Limited | Provider dependent | Strong Integrate Mediatrix gateways, analog and digital systems. |
| Routing customization | Basic cloud-managed routing | Operator-managed routing options | Advanced Custom routes, failover, normalization and policy. |
| High availability / DR control | Platform managed, limited customer design | Operator dependent | Flexible Redundant SBCs, trunks, carriers and recovery sites. |
| Best fit | Simple, standardized deployments | Organizations preferring a managed operator model | Enterprises, government, service providers and critical infrastructure needing control |
Sentinel product comparison
Compare Sentinel CS, Sentinel 100 and Sentinel 400.
Select the platform according to deployment model, scale, gateway requirements and migration complexity.
Sentinel CS
Virtual SBC for centralized, scalable and cloud-ready Teams Direct Routing.
- DeploymentVirtual / private cloud / data center
- Best forLarge enterprises, service providers, centralized architectures
- Gateway interfacesExternal gateways as required
- Migration modelCentralized multi-site or multi-tenant voice
- Primary advantageScalability and deployment flexibility
Sentinel 100
Compact enterprise SBC for secure Teams and SIP trunk deployments.
- DeploymentPhysical appliance
- Best forBranches, regional offices, mid-size enterprises
- Gateway interfacesPure SBC-oriented deployment
- Migration modelDirect Routing and secure SIP edge
- Primary advantageCompact, controlled on-premise SBC
Sentinel 400
Hybrid SBC and media gateway for Teams plus legacy voice integration.
- DeploymentPhysical appliance
- Best forEnterprises with PBX, analog or digital dependencies
- Gateway interfacesIntegrated gateway capabilities
- Migration modelTeams, PBX and gateway coexistence
- Primary advantageHybrid SBC + gateway architecture
Scenario comparison
Which Teams Voice architecture fits your environment?
| Scenario | Recommended direction | Why | Typical M5 platform |
|---|---|---|---|
| Small branch or regional office | Local Direct Routing SBC | On-premise control, simple carrier connection and compact footprint. | Sentinel 100 or Sentinel Mini |
| Large multi-site enterprise | Centralized virtual Direct Routing | Scalable policy, carrier consolidation and centralized operations. | Sentinel CS |
| PBX and analog coexistence | Hybrid SBC + gateway | Preserves legacy systems while Teams users migrate in phases. | Sentinel 400 |
| Service provider / hosted Teams voice | Virtual multi-tenant architecture | Centralized scale, tenant separation and carrier integration. | Sentinel CS |
| Critical infrastructure or government | Redundant Direct Routing with DR | Requires continuity, routing control and security governance. | Sentinel CS, 100 or 400 depending topology |
| Simple cloud-first deployment | Calling Plans or Operator Connect may be sufficient | Lower infrastructure ownership where advanced integration is not required. | M5 assessment may confirm no SBC deployment is needed |
Migration roadmap
Move to Teams Voice in controlled stages.
1
Assess
Inventory PBXs, trunks, DIDs, users, locations and analog dependencies.
2
Compare
Evaluate Calling Plans, Operator Connect and Direct Routing.
3
Design
Select the Sentinel platform, carriers, routing and DR model.
4
Validate
Test TLS, SRTP, call flows, emergency calling and interoperability.
5
Migrate
Move users and sites in phases with monitoring and rollback plans.
Expected outcomes
What the right Direct Routing architecture is designed to improve.
Results depend on the final carrier, network and migration design.
Carrier controlKeep preferred providers, contracts and numbering strategies.
Secure interoperabilityNormalize and protect voice between Teams and enterprise systems.
Lower migration riskTeams and legacy platforms coexist during phased adoption.
Improved resilienceDesign alternate trunks, SBCs and recovery paths.
FAQ
Questions enterprises ask about Teams Direct Routing.
What is Microsoft Teams Direct Routing?
It connects Teams Phone to SIP carriers and the PSTN through a certified Session Border Controller.
Why is an SBC required?
The SBC provides secure demarcation, SIP normalization, routing, topology hiding, TLS and SRTP support.
When is Direct Routing better than Operator Connect?
Direct Routing is generally more suitable when the organization needs custom carriers, advanced routing, PBX coexistence, gateway integration or customer-controlled resilience.
Which Sentinel platform should I choose?
Sentinel CS fits virtual and scalable deployments, Sentinel 100 fits compact appliance SBC needs, and Sentinel 400 fits hybrid SBC and gateway environments.
Can existing PBXs remain during migration?
Yes. Sentinel SBCs can route calls between Teams, PBXs, carriers and gateways during a phased migration.
Can M5 support high availability?
Yes. Direct Routing can be designed with redundant SBCs, SIP trunks, carriers and disaster-recovery sites.
Teams Direct Routing assessment
Compare your options before selecting the Teams Voice architecture.
Provide a high-level overview of the current environment. M5 can help compare Calling Plans, Operator Connect and Direct Routing, then identify the appropriate Sentinel platform.
- Teams users, locations and migration priorities
- SIP trunks, carriers, PBXs and contact centers
- Analog devices and gateway requirements
- High availability and disaster recovery
- Sentinel CS, Sentinel 100 or Sentinel 400 selection