Digium TE121B is a single span, selectable T1 (24-channel), E1 (32-channel), or J1 (24-channel) card. The card utilizes Digium's VoiceBus™ technology. VoiceBus technology allows the TE121B to use an industry standard bus-mastering PCI Express interface, as found in millions of PCs worldwide, to maximize system compatibility and eliminate system conflicts.

Digium's VPMADT032 hardware echo cancellation module provides 1024 taps (128 milliseconds) of echo cancellation for superior echo cancellation on both types of analog interfaces.

The TE121B supports both voice and data modes on its single span. For example, the card can support 12 channels dedicated to voice, routed directly to the Asterisk Open Source PBX, and 12 to data, handled by the underlying Linux operating system, thus eliminating the need for an external router. Supporting PCIe x1, the TE121B may be used in any available PCIe 1.0 compliant slot - 1x, x4, x8, and x16 without considerations for voltage selection or lane size.

By utilizing our TDMoE (TDM over Ethernet) technology, an exclusive Digium process, you can easily connect multiple PCs equipped with the TE121B and achieve voice quality on par with single PBX implementations. Scalability for this product is derived from adding multiple TE121B cards to each individual PC. Add additional cards as you need them for your expanding applications.

The TE121B supports industry standard telephony and data protocols, including both RBS and Primary Rate ISDN (PRI) protocol families for voice and PPP, Cisco HDLC, and Frame Relay data modes. The board drives both line-side and trunk-side interfaces, including call features.