FlexSwitch is a production-ready Class 4 and Class 5 softswitch delivering 5,000+ calls per second with full billing integration, least cost routing, and real-time fraud controls — trusted by ITSPs and wholesale carriers worldwide.
FlexSwitch is a full-featured VoIP softswitch platform supporting both Class 4 (wholesale/carrier transit) and Class 5 (retail/subscriber) call processing. It handles everything from SIP proxy and B2BUA functions to real-time CDR generation, least cost routing, DID management, and comprehensive fraud detection — from a single, unified platform.
Designed for Internet Telephony Service Providers (ITSPs), Competitive Local Exchange Carriers (CLECs), and wholesale voice operators, FlexSwitch scales from hundreds to hundreds of thousands of concurrent calls through horizontal clustering, with sub-second failover between nodes.
Run wholesale transit routing and retail subscriber management on a single platform — eliminating the cost of separate systems.
Handle 5,000 call attempts per second per node, scaling to 100,000+ concurrent calls per cluster with active-active redundancy.
Integrated pre-paid and post-paid rating with instant CDR generation and export to third-party billing systems.
Rate limiting, destination blacklisting, concurrent call caps, and anomaly detection prevent revenue fraud and traffic abuse.
Full RFC 3261 compliant SIP proxy, registrar, and Back-to-Back User Agent supporting SIP REGISTER, INVITE, BYE, REFER, and OPTIONS.
High-capacity A-Z voice transit with carrier peering, CDR settlement, and real-time traffic analytics for wholesale voice operators.
SIP registrar with full subscriber feature set including voicemail, call forwarding, call waiting, conference, and hosted PBX functions.
Multi-dimensional LCR engine routes calls by cost, quality score, ASR/ACD metrics, time-of-day, and origination prefix.
Instant CDR generation with configurable export to CSV, SQL databases, RADIUS/Diameter, or third-party billing platforms.
Centralised DID inventory management with routing rules, number portability support, and per-DID feature configuration.
Concurrent call limits, destination blacklisting, velocity-based rate limiting, and real-time anomaly detection to protect revenue.
Comprehensive browser-based portal for routing configuration, customer management, billing reports, and real-time traffic analytics.
| Protocol | SIP (RFC 3261), H.323 (optional), MGCP (optional) |
| Calls Per Second | 5,000 CPS per node |
| Concurrent Calls | 100,000+ per cluster |
| Call Setup Latency | <20ms (SIP 100 Trying) |
| Routing Modes | LCR, quality-based, time-based, prefix-based, load-balanced |
| Billing | Pre-paid, post-paid, real-time rating engine |
| CDR Export | CSV, SQL/ODBC, RADIUS, Diameter, custom webhook |
| Codecs | G.711 (a/u), G.729, G.722, Opus, iLBC |
| HA | Active-active clustering, sub-second failover |
| OS | Linux (Ubuntu 20.04+, CentOS 7+) |
SS7/SIGTRAN gateway bridging, number portability database integration, and custom routing algorithm development available upon request.
Interconnect with international carriers, route transit traffic at the lowest cost, and generate detailed settlement CDRs for inter-carrier billing.
Offer hosted VoIP services to business and residential subscribers with a full Class 5 feature set, SIP trunking, and DID management.
Provide cloud PBX services to enterprise clients by deploying FlexSwitch as the core switching layer beneath your UCaaS platform.
Our solutions team will walk you through deployment architecture, carrier peering options, and commercial terms to get your platform live quickly.