Digium's dual span digital interface cards support 48 (T1 / J1) or 60 (E1) connections to PSTN trunks over two spans (digital circuits). All dual span models can be combined with an Octasic DSP-based echo cancellation module from Digium to provide effective hardware echo cancellation across all channels.Digium cards are compatible with all versions of Asterisk using the DAHDI driver framework. Asterisk and DAHDI are available for free from the Asterisk.org website.
All cards include a five (5) year warranty and are eligible for Digium's Exceptional Satisfaction Program (ESP) risk-free Quality Guarantee.

