Question 1

What is a Class 4 softswitch?

Accepted Answer

A Class 4 softswitch is a carrier-grade switching system that routes large volumes of voice traffic between networks — connecting carriers, VoIP providers, and telecom operators at the wholesale level.

Unlike Class 5 switches, which handle end-user features like voicemail and call forwarding, Class 4 systems are purpose-built for high-capacity transit routing, least-cost routing decisions, and inter-carrier interconnection.

46 Labs' PeerEdge Voice Infrastructure replaces legacy Class 4 hardware with a software-defined environment that gives carriers real-time routing control without on-premise hardware constraints.

Question 2

How does SIP replace TDM in a carrier network?

Accepted Answer

Session Initiation Protocol (SIP) replaces Time Division Multiplexing (TDM) by moving voice traffic from dedicated copper circuits to IP-based packet networks. TDM allocates fixed bandwidth per call regardless of whether it's in use; SIP dynamically allocates bandwidth only when needed, dramatically reducing cost and improving scalability. Migration typically involves replacing TDM gateway hardware with SIP trunks, re-provisioning routing tables, and validating STIR/SHAKEN compliance on the new infrastructure.

46 Labs manages this migration process end-to-end, mapping every trunk and rate table before cutover to eliminate service disruption.

Question 3

What is a carrier-grade SBC?

Accepted Answer

A Session Border Controller (SBC) at carrier grade is a network element that sits at the edge of a carrier's IP infrastructure to manage, secure, and route SIP traffic between networks. It handles signaling normalization, encryption, transcoding, and fraud prevention at scale — processing millions of concurrent sessions while maintaining call quality and regulatory compliance.

Carrier-grade SBCs differ from enterprise SBCs in their capacity requirements and multi-tenant architecture. PeerEdge Voice Infrastructure includes carrier-grade SBC functionality as part of its core switching environment.

Question 4

What is STIR/SHAKEN and why does it matter for carriers?

Accepted Answer

STIR/SHAKEN (Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs) is the FCC-mandated framework that authenticates the caller ID of calls traversing the PSTN. Carriers are required to implement STIR/SHAKEN to sign and verify calls passing through their networks, reducing robocall fraud and improving consumer trust. Non-compliant carriers face FCC enforcement action and may be blocked by downstream providers.

46 Labs' infrastructure is built with STIR/SHAKEN compliance integrated, not bolted on.

Question 5

What is wholesale voice termination?

Accepted Answer

Wholesale voice termination is the service of routing and completing call traffic originated by one carrier onto another carrier's network, ultimately delivering the call to its destination. Wholesale termination is typically sold in bulk at per-minute rates and is the core commercial model for carriers operating Class 4 infrastructure.

46 Labs provides wholesale voice termination with automated least-cost routing, real-time quality analytics, and vendor management tools through PeerEdge Voice Infrastructure.

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About Carrier Solutions

VOICE
INFRASTRUCTURE 
& CONNECTIVITY

46 Labs, LLC.

© 2026

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Service Terms

AUP

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© 2026

CLICK TO LISTEN AND SUBSCRIBE

QUICK ANSWERS

About Carrier Solutions

What is a Class 4 softswitch?

How does SIP replace TDM in a carrier network?

What is a carrier-grade SBC?

What is STIR/SHAKEN and why does it matter for carriers?

What is wholesale voice termination?

VOICEINFRASTRUCTURE & CONNECTIVITY

46 Labs, LLC.

© 2026

Trademark Policy

Service Terms

AUP

Tariffs

Privacy Policy

© 2026

VOICE
INFRASTRUCTURE 
& CONNECTIVITY