Routing & Softswitch
Wholesale Voice Core
Ref: ITU-T Recommendation Q.850 / ITU-T E.411 / IETF RFC 3261
Class 4 Softswitch
Wholesale Telecommunications VoIP Routing & Billing Softswitch
Direct Telecom Definition • Carrier Industry Standard
A high-capacity softswitch platform engineered for wholesale carriers to route long-distance and international VoIP traffic with real-time Least-Cost Routing (LCR), protocol normalization, and interconnect billing.
Technical Definition & Carrier Engineering Standards
A Class 4 Softswitch is the central routing and billing brain of a wholesale voice network. Unlike Class 5 switches that serve end-user telephone lines, Class 4 softswitches interconnect carrier trunks, managing tens of thousands of concurrent SIP calls between telco operators. Features include real-time LCR engines, quality-based routing (QBR) tracking ASR/PDD, bilateral CDR generation, and anti-FAS detection.