VoIP BRI Gateway Yeastar TB200/TB400 — ISDN Trunking for IP Systems

The Yeastar TB Series comprises VoIP BRI gateways designed to integrate ISDN BRI lines into SIP-based VoIP infrastructure, enabling bidirectional communication between ISDN and IP telephony networks. These gateways are deployed to connect legacy PBX systems to modern VoIP services or to add ISDN BRI trunking to IP-only environments — addressing scenarios where existing ISDN infrastructure must be retained during migration to VoIP. The TB200 provides 2 BRI ports supporting up to 8 concurrent calls; the TB400 offers 4 BRI ports for expanded capacity.

Each BRI port is software-configurable in NT or TE mode, supporting Point-to-Point and Point-to-Multipoint connections with compatibility for National ISDN Type 1 and 2, Nortel DMS100, AT&T 4ESS, Lucent 5ESS, EuroISDN, and Q.SIG switch types. Voice processing covers G.711, G.722, G.723, G.726, G.729A, GSM, ADPCM, and iLBC codecs, ITU-T G.168 echo cancellation, and SIP transport secured via TLS and SRTP. Both T.30 and T.38 fax support ensure reliable fax transmission in traditional and IP modes.

The TB Series integrates with existing ISDN PBX systems, IP-PBX platforms, and softswitches via SIP RFC3261 without replacing active telephony equipment. Network features include DDNS, NAT traversal, QoS/ToS, and static routing, supporting deployment across business networks with varied topologies. Administration is fully web-based with packet capture tools, configuration backup/restore, and firmware upgrade via HTTP/TFTP.

The Yeastar TB Series is deployed for connecting legacy PBX systems to VoIP services via SIP trunking, adding ISDN BRI trunks to IP-only telephony systems, and interconnecting multiple PABX locations for cost-free inter-office calls. Typical use cases include contact centers requiring ISDN connectivity, branch offices linking IP-PBX to headquarters, and organizations executing phased migration from ISDN BRI infrastructure to VoIP.