The Yeastar TG200L is a 2-Port 4G/LTE VoIP Gateway that directly connects mobile networks with IP-based telephone systems. It enables bidirectional communication between LTE/4G networks and VoIP systems, allowing calls to be made both from VoIP to mobile and vice versa. The device is specifically designed as a fallback solution in case of a fixed-line connection failure, ensuring uninterrupted telephone connectivity in the business. Integration into existing IPPBX systems or softswitch solutions is simple and quick, thanks to high compatibility and a web-based management interface.

Applications
This gateway is suitable for businesses requiring redundant communication infrastructure to remain reachable during fixed-line outages. It can also be used to reduce costs by leveraging mobile-to-mobile calls and SIP trunks to lower telephone expenses. Support for mass SMS via a web interface extends functionality for applications such as alarm systems, notifications, or marketing campaigns.

Features and Specifications in Detail
The device features two mobile ports, each supporting 4G/LTE networks depending on the module type. The exact frequency bands and compatible operators depend on the specific module. GSM frequencies include 850/900/1800/1900 MHz, while WCDMA frequencies cover 850/1900 MHz, 850/2100 MHz, and 900/2100 MHz. Supported VoIP protocols include SIP and IAX2, along with transport protocols such as UDP, TCP, TLS, and SRTP. Voice encoding is handled via various codecs, including G.711 (alaw/ulaw), G.722, G.729A, GSM, ADPCM, and Speex, enabling flexible adaptation to different network requirements. DTMF modes such as RFC2833, SIP Info, and In-band are also integrated to ensure reliable transmission of keypad values (e.g., during PIN entry). Echo cancellation follows ITU-T G.168 LEC, ensuring clear voice quality.

Technology Explained Simply
NAT traversal functions such as Static NAT and STUN ensure stable network connections, even in complex environments with firewalls or NAT routers. The gateway supports network protocols like FTP, TFTP, HTTP, and SSH, enabling configuration and maintenance through various channels. Network settings include DHCP, DDNS, firewall, OpenVPN, static IP addresses, QoS (Quality of Service), and VLAN, optimizing network security and performance. Power supply is provided via DC 12V/1A or AC 100–240V, allowing flexible installation in various locations.

Compatibility and Accessories
The gateway is compatible with SIP-based PBX, VoIP, and softswitch systems. It can be used with a web interface for SMS messaging, including support for mass SMS. Integration into existing telephone systems is performed via the web-based management interface. No specific accessory products are mentioned in the sources.

Mounting and Installation
The device is designed for indoor use. Dimensions are 213 x 160 x 44 mm. Installation is performed via the web-based interface, where network settings and mobile port configurations are managed through the interface. Power supply is provided via an external power adapter (DC 12V/1A) or directly via AC 100–240V.

Operational Advantages
Operating the Yeastar TG200L provides a cost-effective backup in case of fixed-line failure. Utilizing mobile-to-mobile calls and SIP trunks can significantly reduce telephone costs. The web-based management interface enables easy configuration and maintenance. Support for mass SMS expands application possibilities across various business departments.

Operating temperature ranges from 0°C to 40°C, while storage temperature ranges from -20°C to 65°C. Humidity levels are 10–90% (non-condensing). The device is not designed for outdoor use, as no protection rating such as IP67 is specified.