Yeastar S20 S-Series VoIP PBX for Small Business

The Yeastar S20 is a compact, stand-alone VoIP PBX designed for small businesses and home offices with up to 20 users. Its modular design allows you to customize analog, digital, and mobile telephony interfaces without additional licensing fees, while delivering professional-grade communication features like voicemail, call recording, and unified communications through the Linkus UC Client. With support for multiple VoIP trunks, flexible module options, and advanced security, the S20 is ideal for businesses seeking a scalable and reliable telephony solution.

Product Features

Modular Telephony Interfaces

The S20 includes two onboard slots for modular expansion, allowing you to choose the right combination of FXS, FXO, BRI, or GSM/4G LTE channels to match your office setup. Modules can be swapped or upgraded as your business grows.

Unified Communications

Integration with Yeastar’s Linkus UC Client enables desktop and mobile extensions for Windows, Mac, iOS, and Android, letting users stay connected on the go while accessing voicemail, presence, and chat features.

Built-in Call Recording

Supports automatic call recording and storage without requiring extra hardware or software, making compliance and quality monitoring easier for small teams.

App Center Support

The S20’s App Center allows businesses to add independent applications such as Hotel App, Billing, CRM integration, and Auto Provisioning, expanding the PBX’s functionality beyond standard telephony.

Advanced Security

The S20 features a built-in firewall, supports TLS and SRTP encryption, and includes IP blocking and DDoS protection to ensure secure communication across networks.

Easy Management

A web-based GUI provides intuitive configuration, including automated attendants (IVR), voicemail-to-email, call routing, and system monitoring, making administration simple for small IT teams.

Product Specifications

• Capacity: 20 extensions; 10 concurrent calls
• VoIP Trunks: Supports up to 20 SIP/IAX2 trunks
• Modular Slots: 2 onboard slots for FXS/FXO/BRI/GSM modules
• Analog Modules:
  • O2: 2 FXO ports
  • S2: 2 FXS ports
  • SO: 1 FXS + 1 FXO port
  • B2: 2 BRI ports
  • GSM/4G LTE: 1 channel
• Storage: Micro SD/TF card slot for voicemail and call recording
• Ethernet Ports: 2 × 10/100 Mbps (WAN/LAN)
• Networking Protocols: DHCP, Static IP, PPPoE, VLAN, VPN (OpenVPN, L2TP, IPsec), DDNS, QoS, NAT Traversal (STUN, Static NAT)
• Telephony Protocols: SIP (RFC3261), IAX2; UDP, TCP, TLS, SRTP transport
• Audio Codecs: G.711 (A/μ), G.722, G.726, G.729A, GSM, Speex, ADPCM, iLBC
• Video Codecs: H.263, H.263P, H.264, MPEG4
• Fax Support: T.38 Fax-over-IP, Fax-to-email
• Physical Dimensions: 160 × 160 × 30 mm
• Weight: ~0.3 kg
• Power Supply: DC 12V 1A adapter
• Power Consumption: 1.8W–10.6W
• Mounting: Desktop or wall-mountable
• Operating Environment: 0°C–40°C, 10%–90% humidity non-condensing
• Third-Party Phone Support: Auto-provisioning for over 500 IP phone models (Yealink, Cisco, Poly, Grandstream)