Yeastar S20 is a modular VoIP PBX for small-to-midsize businesses that lets you choose what kinds of port work for your deployment. The S20 has two on-board module slots and can support the following modules:

• S2 Module: 2 FXS Ports
• O2 Module: 2 FXO Ports
• SO Module: 1 FXS Port & 1 FXO Port
• B2 Module: 2 BRI Ports
• GSM Module: 1 GSM Channel
• 3G Module: 1 WCDMA Channel
• 4G LTE Module: 1 3G/4G Voice Call & Data

Note that the S20 only has one antenna jack, so only one of the GSM, 3G, or 4G LTE Modules can be integrated.

Yeastar S20 IP PBX handles 20 users with a maximum of 10 concurrent calls, giving you full telephony functionality including call routing and transfer, fax to email, conferencing, queuing, and much more. Using the Linkus Mobile Client app for Android and iOS, you can even make mobile phones part of the office phone system. Managing the phone system is simple using the graphical user interface of the online Configuration Panel, which allows you to access the phone system securely from anywhere with internet access. S20 supports TLS and SRTP encryption to secure your communications. This compact IP PBX can be desk or wall mounted.

Yeastar S20 IP PBX Quick Specs:

• Communications Protocols: SIP, IAX2
• Module Slots: 2
• Physical Interfaces:
  • 1x WAN 10/100 Ethernet Port
  • 1x LAN 10/100 Ethernet Port
  • 1x Antenna Socket
  • 1x TF Card Slot
• Users: 20
• Concurrent Calls: 10
• Maximum Ports with Modules (Not Included):
• FXS Ports: 4
• FXO/BRI Ports: 4
• GSM/3G/4G Channels: 1
• 4G Channels (Data): 1
• E1/T1/PRI Ports: 0
• VoIP Trunks: 20
• Audio Codecs: G.711u/a, G.722, G.726, G.729A, GSM, Speex, ADPCM, iLBC
• Video Codecs: H.263, H.263P, H.264, MPEG4
• Fax Over IP: T.38
• Mounting: desktop, wall

Yeastar S20 20 User 10 Concurrent Calls IP Phone System Package Contents:

• S20 IP PBX
• Power Adapter
• Ethernet Cable
• 2x Telephony Lines
• 4x Rubber Feet
• Warranty Card
• Quick Installation Guide