Synway’s next-generation Session Border Controller (SBC) includes hardware SBC models (SBC‑30/60/120/250/500/1000/2000 and hybrid series) and pure software PURESOFT‑SBC. It supports 5 up to 100,000 concurrent SIP sessions, targeting service providers, large enterprises, contact centers, government emergency communications and cross-border BPO scenarios. Deployed at network boundaries, it acts as a SIP trunk interconnection gateway to realize heterogeneous multimedia network interworking, security isolation, media processing and service assurance.
The Hybrid series is an SBC+TDM hybrid all-in-one device, integrating E1/T1 PSTN interfaces to support IP‑TDM interworking with PSTN Fallback. It enables smooth migration from legacy TDM to VoIP networks. Pure IP models are designed for cloud SIP trunk and cloud communication interconnection. PURESOFT‑SBC is a software-based SBC deployable on virtualized servers for cloud-native architectures.
Core Capabilities
B2BUA Signaling Processing & SIP Normalization
Built on full B2BUA (Back-to-Back User Agent) architecture rather than a simple SIP proxy. It performs SIP header manipulation, Digit Manipulation, handling of 3xx redirects, REFER, PRACK and Early Media, plus DTMF (RFC2833 / SIP‑INFO) and T.38 fax interworking. It supports SIP over UDP/TCP/TLS transport conversion to resolve protocol incompatibility between multi-vendor SIP platforms, IP-PBX and cloud SIP trunks, with over 500 live deployments for carriers and enterprises.
Comprehensive Security Protection (VoIP Firewall)- Wire-speed DoS/DDoS defense, IDS and dynamic blacklist to mitigate VoIP fraud, toll fraud and eavesdropping;
- Signaling encryption via TLS/IPSec, media encryption via SRTP;
- Topology Hiding masks real internal IP addresses so external networks cannot discover private network topology;
- ACL access control, SIP Digest authentication and registration rate limiting to serve as a VoIP firewall and block unauthorized session access.
Hardware DSP Media Transcoding & Voice Quality Assurance
Equipped with dedicated DSP resources without external transcoding servers. It supports codec conversion between G.711, G.723.1, G.729A/B, iLBC, AMR-NB, SILK and Opus. It integrates G.168 echo cancellation, programmable jitter buffer, silence suppression and RTP redundancy. Direct Media / Hair-pin mode reduces bandwidth consumption. It supports SIPREC (SynAPI recording interface) to connect with contact center recording systems for compliance recording. The optional WebRTC controller enables web-based audio services. QoS features include 802.1P/Q VLAN tagging and DSCP/TOS marking to prioritize media streams.
Telco-Grade High Availability & Survivability
1+1 active-standby HA redundancy for uninterrupted active calls during failover. When WAN links fail at branch sites, local survivability keeps on-site calls running. Hybrid H models support PSTN Fallback: outbound calls automatically switch to E1/T1 PSTN lines upon IP connectivity loss, meeting emergency calling requirements such as E911. IPv4/IPv6 dual stack and VPN networking are supported, together with robust NAT Traversal to solve SIP communication issues under NAT environments for internal and external terminals.
Intelligent Routing, Load Balancing & O&M
Multi-dimensional routing policies based on SIP trunks, DID ranges, SIP headers and bandwidth. It supports alternate routes, Least Cost Routing (LCR), call forking and Load Balancing. Call Admission Control (CAC) limits concurrent sessions and registration rates per peer. Administration can be done via Web GUI, SNMP and INI configuration files, with built-in signaling diagnostic tools for troubleshooting. Bandwidth throttling and multi-level resource balancing optimize boundary traffic for contact centers, SIP trunk wholesale / retail and mobile VAS services.
Typical Use Cases
✅ Contact Center: Interconnection of legacy TDM contact centers with cloud SIP trunks, cross-border BPO remote agents;
✅ Service Providers & SIP Trunk Operators: Enterprise SIP Trunk access, isolation between enterprise private networks and carrier core networks;
✅ Enterprise Unified Communications: IP-PBX interconnection with carrier SIP trunks, internal-external network security isolation;
✅ Government & Emergency Services: PSTN fallback on WAN failure to guarantee emergency calls;
✅ Legacy TDM Network Migration: H-series hybrid SBC acts as gateway for smooth TDM-to-IP transition.
Future Trends of Session Border Controller (SBC)
Trend 1: Transition from Hardware SBC to Virtual SBC & Cloud-Native SBC
Hardware SBC will remain critical for edge carrier and government sites requiring high security and local survivability. Meanwhile, Virtual SBC and Cloud-Native SBC (e.g. Synway PURESOFT‑SBC) will keep gaining market share. Deployed on virtual machines or Kubernetes containers, they enable elastic scaling of SIP session capacity and lower hardware capital expenditure. Hybrid deployment will become mainstream: hardware SBC at branches for local survivability, virtualized SBC in headquarters/cloud for centralized service orchestration.
Trend 2: SBC Evolves from Pure Signaling/Media Gateway to Converged Edge Communications Platform
Traditional SBC mainly focuses on B2BUA, transcoding and NAT traversal. Next-generation SBC integrates WebRTC gateway, SIPREC recording, AI signaling analytics and compliance auditing. Beyond boundary isolation, modern SBC delivers session observability, intelligent anomaly detection and automated fraud blocking. WebRTC will become a standard module to connect browser-based audio/video clients with traditional SIP endpoints, no plugin required. Synway’s optional WebRTC controller is built for this market shift.
Trend 3: Strengthened SBC Boundary Security amid Evolving VoIP Threats
VoIP attacks including malformed SIP packets, DoS/DDoS, toll fraud and man-in-the-middle eavesdropping keep evolving. SBC will adopt advanced IDS, dynamic threat intelligence, TLS 1.3 and DTLS-SRTP encryption. Topology hiding, session authentication, anti-fraud number validation and full session audit logging become mandatory for compliance requirements such as SIPREC call recording and communication log retention. The SBC’s role as a VoIP Firewall will be further emphasized as the first security barrier for VoIP networks.
Trend 4: Expanded SBC Application Scope Driven by 5G and Edge Computing
Within 5G VoLTE / VoWiFi and edge communication scenarios, SBC enables inter-domain session interworking. Lightweight SBC deployed at the edge processes RTP media locally to reduce latency. For private government networks and public-private network interconnection, SBC acts as cross-domain session controller for protocol normalization between IMS, SIP and legacy TDM. Hybrid TDM-IP SBC models like Synway H-series will maintain long-term value in markets with large legacy TDM assets, where PSTN Fallback survivability is a core competitive advantage.
Trend 5: Intelligent O&M — Enhanced Observability & Automation
Instead of manual packet capture for troubleshooting, modern SBC embeds deep diagnostic capabilities to monitor real-time session metrics: concurrent sessions, transcoding resource utilization, QoS metrics (jitter, packet loss, latency) and alarm triggering. Open APIs enable integration with third-party O&M platforms for automated configuration and self-healing. AI-powered intelligent routing evaluates link quality dynamically and selects optimal trunks automatically to reduce operational workload.
Synway SBC Competitive Highlights
- Full hardware & software product matrix: SBC‑30 for small deployments up to SBC‑2000 for high capacity, plus H hybrid TDM models and PURESOFT‑SBC virtual edition, covering SMB, contact center and carrier-grade scenarios.
- Integrated media processing: Onboard DSP hardware transcoding, eliminating separate transcoding servers and reducing total solution cost.
- Telco-grade survivability: 1+1 HA, local call survivability and PSTN fallback to maintain service during WAN outages for high-reliability use cases.
- Complete standard SBC feature set: Full B2BUA, SIP normalization, NAT traversal, TLS/SRTP encryption, DoS/DDoS protection, SIPREC and optional WebRTC, covering all mainstream Session Border Controller functions.
- Proven field experience: Deployed widely for carriers, BPO contact centers, financial and overseas projects, handling complex heterogeneous network environments.
About Synway
Synway
Information Engineering Co., Ltd. is a professional telecommunications
manufacturer with over 30 years of expertise in TDM-IP interconnection
and enterprise Unified Communications solutions. Trusted by partners
worldwide, Synway delivers carrier-grade VoIP gateways, FXS SIP
gateways, E1 gateways, analog gateways, and digital media gateways,
alongside IP-PBX systems and voice processing boards that power
mission-critical communications across diverse industries.
synway
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