01
Prevent SIP Exposure
Reduce exposure to SIP scanning, unauthorized traffic, malformed messages and attacks targeting public-facing voice infrastructure.
Sentinel Session Border Controllers
Secure enterprise voice with Sentinel SBC solutions.
Protect SIP trunks, Microsoft Teams Direct Routing, cloud voice, PBX interconnection and critical communications with M5 Technologies Sentinel Session Border Controllers. Sentinel SBCs help organizations secure voice traffic, reduce telecom risk, control interoperability and modernize voice infrastructure without exposing the network edge.
M5 Sentinel SBC Core
SIP SECURITY • TEAMS SBC • VIRTUAL SBC • PRI/BRI/FXS/FXO
SIP TRUNKS
TEAMS VOICE
PBX / CLOUD
CRITICAL VOICE
SIPSecure voice edge
SBCPolicy and routing
TeamsDirect Routing
SIP SecurityProtect SIP trunks, signaling, media paths and voice interconnection points.
Teams Direct RoutingDeploy a controlled SBC layer between carriers, PBXs and Microsoft Teams Phone.
InteroperabilityNormalize SIP behavior between carriers, cloud voice, legacy PBXs and enterprise systems.
ContinuityMaintain secure voice operations across enterprise, government and critical infrastructure sites.
What is a Session Border Controller?
An SBC is the secure control point between your voice network and everything outside it.
A Session Border Controller sits at the edge of a voice network and controls SIP sessions between trusted and untrusted networks. It protects SIP trunks, normalizes signaling, enforces routing policy, supports Microsoft Teams Direct Routing, hides internal topology and helps prevent unauthorized or malformed VoIP traffic from reaching critical voice systems.
Carrier / SIP Trunk / PSTN
External voice services, SIP providers, hosted PBX, PSTN access and public network interconnection.
Sentinel SBC
Policy enforcement, SIP security, TLS/SRTP strategy, routing, normalization and voice-edge control.
PBX / Teams / Cloud Voice
Internal enterprise communications, Microsoft Teams Phone, IP PBX, contact center and critical voice services.
Why every organization needs an SBC
Voice is now a cybersecurity, continuity and cloud migration issue.
Organizations that connect SIP trunks, Microsoft Teams, PBXs, emergency systems or cloud voice platforms need a controlled voice edge. Without an SBC, SIP infrastructure can become exposed to toll fraud, scanning, malformed traffic, routing errors, interoperability issues and business continuity failures.
02
Reduce Toll Fraud Risk
Apply call policy, routing rules and access controls to reduce the risk of unauthorized calling and voice service misuse.
03
Secure Microsoft Teams Voice
Create a secure Direct Routing architecture between Microsoft Teams Phone, carriers, SIP trunks and enterprise voice systems.
04
Normalize SIP Interoperability
Manage differences between carriers, PBXs, cloud voice systems, contact centers and enterprise UC environments.
05
Protect Business Continuity
Improve resilience for distributed sites, failover planning, emergency voice, critical operations and migration projects.
06
Control Voice Modernization
Modernize from legacy voice to SIP and cloud while preserving control over routing, security, compliance and service quality.
Sentinel SBC portfolio
Three Sentinel SBC options for enterprise, cloud and critical infrastructure voice.
Select Sentinel CS for virtual or cloud SBC architecture, Sentinel 400 for larger appliance-based enterprise and critical infrastructure deployments, and Sentinel 100 for focused enterprise, branch and Microsoft Teams Direct Routing projects.
Virtual SBC
Sentinel CS
Virtual Session Border Controller for cloud, hosted voice, operator networks and centralized enterprise SIP security.
High-performance appliance
Sentinel 400
Appliance SBC for larger enterprise, government, defense, utilities, transportation and mission-critical environments.
Enterprise appliance
Sentinel 100
Enterprise SBC for secure SIP trunking, Microsoft Teams Direct Routing, branch voice and PBX modernization.
Sentinel SBC comparison
Choose the right Sentinel SBC for your voice architecture.
Use these tables to compare Sentinel CS, Sentinel 400 and Sentinel 100 by deployment type, use case, interface requirements and buyer profile.
Model
Deployment
Best For
Primary Role
Recommended Buyer
Sentinel CS
Virtual / cloud / data center
Operators, hosted voice, cloud voice, large distributed deployments
Scalable SIP security and centralized SBC control
Service providers, cloud voice providers and large enterprises needing virtual SBC scale.
Sentinel 400
Physical appliance
Large enterprise, government, utilities, transportation and critical infrastructure
Secure production-grade SBC and gateway-oriented voice edge
Organizations needing robust on-premise control, resilience and hybrid telephony integration.
Sentinel 100
Physical appliance
SMB, branch, mid-size enterprise and focused Teams Direct Routing projects
Cost-effective SIP demarcation, policy and voice-edge protection
IT teams needing secure SIP trunking and cloud voice migration without oversized infrastructure.
Feature / Requirement
Sentinel CS
Sentinel 400
Sentinel 100
Why It Matters
Recommendation
Virtual SBC
✓
—
—
Virtualization supports cloud, hosted and centralized network architecture.
Choose Sentinel CS for virtual deployments.
Microsoft Teams Direct Routing
✓
✓
✓
Teams voice requires secure SIP interconnection between Microsoft Phone System and carriers.
Choose by scale and deployment model.
SIP trunk security
✓
✓
✓
Protects the enterprise voice edge and controls external interconnection.
All Sentinel SBCs apply.
FXS interface option
—
✓
✓
Connect analog phones, emergency phones, fax and facility systems.
Choose Sentinel 100 or 400 if analog endpoint ports are required.
FXO interface option
—
✓
✓
Connect to PSTN lines or legacy analog trunks.
Choose Sentinel 100 or 400 when analog line-side access is needed.
BRI interface option
—
✓
✓
Supports ISDN BRI migration and interconnection.
Choose Sentinel 100 or 400 for BRI modernization.
PRI / T1 / E1 interface option
—
✓
✓
Supports digital PBX trunk migration and carrier handoff.
Choose Sentinel 400 for larger PRI projects; Sentinel 100 for smaller deployments.
Service provider architecture
✓
✓
—
Hosted voice and operator networks need scalable SBC control.
Sentinel CS is the primary recommendation.
Critical infrastructure
✓
✓
✓
Operational voice needs availability, policy and secure interconnection.
Sentinel 400 is usually strongest for on-premise critical sites.
Requirement
Recommended Sentinel
Reason
CTA
Microsoft Teams Direct Routing
Sentinel 100 / 400 / CS
Choose based on site count, call volume and virtual versus appliance deployment.
Large enterprise or government site
Sentinel 400
Strong appliance positioning for robust on-premise secure voice edge.
Branch or mid-size enterprise
Sentinel 100
Cost-effective SBC appliance for focused SIP security and Teams voice projects.
Service provider or hosted voice
Sentinel CS
Best fit for scalable centralized SBC and cloud voice control.
PRI / BRI / FXS / FXO required
Sentinel 100 or Sentinel 400
Hardware interface options are available through appliance configurations.
Telephony interface options
FXS, FXO, BRI and PRI options for Sentinel appliance deployments.
Sentinel 100 and Sentinel 400 can be configured with telephony interface cards depending on project requirements. This makes them useful when SIP security must coexist with legacy analog or digital voice interfaces.
FXS
- Connects analog phones and endpoint devices
- Useful for emergency phones, elevator phones, fax and legacy analog equipment
- Common in POTS replacement and facilities voice modernization
FXO
- Connects to PSTN analog lines or analog PBX trunks
- Useful for legacy line-side access and fallback scenarios
- Supports migration where analog trunks still exist
BRI
- Supports ISDN BRI interconnection
- Useful for regions or customers maintaining BRI infrastructure
- Helps bridge smaller digital voice environments to SIP
PRI / T1 / E1
- Supports PBX trunk migration and carrier handoff
- Useful for larger digital telephony modernization projects
- Connects legacy PRI/T1/E1 infrastructure to SIP architecture
Sentinel 100 / Model M Slot Code
Interface Option
Port Count
Typical Use
Commercial Note
2
PRI / T1 / E1 card
1 PRI
PBX trunk migration, digital voice interconnection, carrier handoff.
Use when bridging SIP with legacy PRI/T1/E1 infrastructure.
3
FXS card
4 FXS
Analog phones, fax, elevators, alarms and POTS replacement devices.
Best for larger analog endpoint density on Sentinel 100.
4
FXO card
4 FXO
PSTN lines, PBX analog trunks and legacy analog line environments.
Use where analog line-side interconnection is required.
5
FXS card
2 FXS
Smaller analog endpoint deployments and compact POTS replacement use cases.
Good for branch sites with limited analog requirements.
6
BRI card
2 BRI
ISDN BRI migration and smaller digital voice interconnection.
Use where BRI rather than PRI is still present.
7
FXO card
2 FXO
Small PSTN or analog trunk interconnection.
Good for branch or limited line-side deployments.
8
BRI card
4 BRI
Higher-density ISDN BRI migration and PBX interconnection.
Use when multiple BRI interfaces are required.
L
FXS-LP card
4 FXS-LP
Low-power analog endpoint integration.
Available as a listed slot option for Model M.
Sentinel 400 / Model S Slot Code
Interface Option
Port Count
Typical Use
Commercial Note
2
PRI / T1 / E1 card
1 PRI
Large PBX trunk migration, carrier interconnection and digital telephony modernization.
PRI cards must be installed first in slot order on units with PRI ports.
3
FXS card
4 FXS
Analog endpoint support for phones, fax, elevator lines, alarms and facilities voice.
FXS/FXO/BRI cards are installed after PRI and DSP according to slot-order rules.
4
FXO card
4 FXO
PSTN line connection, PBX analog trunk integration and legacy analog interop.
Recommended when on-premise analog trunk-side access is required.
8
BRI card
4 BRI
ISDN BRI migration and digital branch / PBX interconnection.
Useful for regions or customers maintaining BRI infrastructure.
L
FXS-LP card
4 FXS-LP
Low-power analog endpoint integration.
Listed as a Model S slot option.
Final sizing and SKU validation should be confirmed with M5 Technologies based on call volume, codec policy, redundancy, Microsoft Teams Direct Routing requirements, interface cards and deployment environment.
SBC use cases by industry
Sentinel SBCs protect voice where communication failure is not acceptable.
Enterprise, government and critical infrastructure organizations use SBCs to secure SIP, control voice interconnection and maintain continuity across cloud, hybrid and legacy environments.
Government
Secure SIP trunks, PBX migration, Teams Direct Routing and controlled interconnection for public-sector networks.
Defense
Protected voice-edge architecture for secure facilities, command sites and sensitive communication environments.
Utilities
Voice continuity for control rooms, distributed sites, substations and operational communications.
Airports
Secure operational voice, emergency communications, SIP interconnection and critical facility voice modernization.
Rail
Resilient communications for stations, operations centers, maintenance sites and emergency workflows.
Oil & Gas
Secure SIP and voice continuity for remote facilities, operations centers and high-availability infrastructure.
Healthcare
Protected voice services for facilities, emergency workflows and regulated communication environments.
Finance
Secure SIP trunks, branch voice, recorded environments and hybrid cloud voice migration.
Why M5 Technologies for SBC?
Focused SIP engineering for organizations that need secure voice, not generic telecom complexity.
M5 Technologies brings decades of real-time communications engineering, DGW firmware expertise, SIP interoperability know-how and enterprise voice infrastructure experience to each Sentinel SBC deployment.
SIP Interoperability ExpertiseSentinel SBCs help normalize signaling between carriers, PBXs, cloud platforms and Microsoft Teams environments.
DGW Firmware FoundationSentinel appliance platforms are supported by the DGW software ecosystem and M5 technical documentation.
Critical Infrastructure FitM5 positions SBCs for government, defense, utilities, transportation, enterprise IT and operator-grade voice projects.
Sentinel SBC FAQ
Questions enterprise buyers ask before deploying an SBC.
Why do we need a Session Border Controller?
An SBC protects and controls SIP communications at the voice edge. It helps reduce exposure to unauthorized SIP traffic, toll fraud, malformed messages, routing errors and interoperability issues between carriers, PBXs, Microsoft Teams and cloud voice platforms.
Which Sentinel SBC is best for Microsoft Teams Direct Routing?
The right model depends on deployment type, call volume, site count and interface requirements. Sentinel CS fits virtual and centralized architecture, Sentinel 400 fits larger appliance deployments, and Sentinel 100 fits smaller enterprise or branch SBC projects.
Can Sentinel SBCs support FXS, FXO, BRI or PRI?
Sentinel 100 and Sentinel 400 appliance configurations can support telephony interface cards such as FXS, FXO, BRI and PRI depending on SKU and slot configuration. Sentinel CS is virtual and does not provide physical telephony ports.
Is Sentinel CS a virtual SBC?
Yes. Sentinel CS is positioned as a virtual SBC for cloud, local virtualization, hosted voice, operators and centralized enterprise SIP security use cases.
Is an SBC only required for large organizations?
No. Any organization exposing SIP trunks or connecting Teams, PBX, cloud voice or critical voice services can benefit from SBC security, routing control and interoperability. The correct model depends on architecture and scale.
Can M5 help validate the correct Sentinel SKU?
Yes. M5 Technologies can help validate the correct Sentinel SBC model and SKU based on session capacity, interface cards, redundancy, carrier requirements, Teams architecture and deployment environment.
Free Sentinel SBC assessment
Find out which Sentinel SBC fits your voice infrastructure.
Request a focused review for SIP security, Microsoft Teams Direct Routing, virtual SBC architecture, PRI/BRI migration, FXS/FXO requirements, critical infrastructure voice or secure enterprise voice modernization.
- Sentinel CS, Sentinel 400 or Sentinel 100 recommendation
- SIP trunk and Teams Direct Routing architecture review
- FXS, FXO, BRI and PRI interface requirement validation
- Critical infrastructure and government voice-edge planning
- SKU validation and deployment roadmap