The Hidden Risk of Softphones: Why TSG Still Matters in Teams Telephony
Softphones changed the endpoint and the risk model
The adoption of Microsoft Teams for voice, video, messaging and content sharing across federal agencies has accelerated the decommissioning of traditional desk phones as they migrate to applications on a PC. This convergence, however, fundamentally alters the security architecture as it pertains to protecting conversations in secure spaces. The endpoint is no longer a controlled telephony device but a computing platform, and the peripherals used for communication are no longer fixed or limited in scope as they were on phones. Since the migration away from the desk phone instrument doesn’t relieve an agency or organization of the mandate to be TSG-compliant in secure spaces, administrators must ensure they implement other mechanisms to stay compliant.
Collaboration is now treated as a mission system
This shift is more than an IT modernization milestone, it is increasingly being treated as a mission requirement. In an April 2026 SIGNAL Executive Video published by AFCEA International, warned that “delays or breakdowns in collaboration can directly impact mission outcomes,” and emphasized that “secure collaboration enables agencies to share the right information with the right people at the right time.” In other words, when Teams becomes the voice platform, the reliability and security of the endpoint environment becomes part of mission assurance, not just user convenience.
Why Teams breaks the “on-hook” assurance model
Microsoft Teams fundamentally decouples user interaction from hardware state. Initiating or ending a call is now a software action, typically performed through a GUI, while the underlying hardware remains continuously connected. Microphones, speakers, and cameras represent potential points of vulnerability if not properly controlled as they are always electrically available to the system, regardless of whether the user is actively engaged in a call. This creates a disconnect between user perception and actual device state, undermining the assurance model that TSG requirements were designed to enforce.
Reintroducing physical control with Positive Disconnect Devices (PDDs)
In a Teams-driven environment, the concept of “on-hook” security no longer has a physical equivalent unless it is deliberately reintroduced through additional controls. CIS Secure re-establishes this TSG principle by introducing a physical control point between the PC and its audio/video peripherals with Positive Disconnect Devices (PDDs). By leveraging a PDD and ensuring the use of our compliant peripherals, agencies transition authoritative control for enabling or disabling audio and video transmission from the Teams software interface to the PDD hardware. In doing so, we create a secure foundation for the continued evolution of government collaboration while maintaining compliance in secure areas and embracing the capabilities of platforms like Microsoft Teams.
Bottom line: stay TSG-aligned as Teams telephony scales
Ask CIS Secure how we can help you stay compliant with a PDD and peripherals. As federal leaders increasingly emphasize that collaboration should be treated “as a mission system, not a convenience” (AFCEA SIGNAL, April 2026), TSG-aligned endpoint control becomes a practical requirement for secure spaces, not an optional add-on. See more information in the “TSG Compliance in the Age of Softphones” white paper.
