Digium's dual span digital interface cards support 48 (T1 / J1) or 60 (E1) connections to PSTN trunks over two spans (digital circuits). Built exclusively for use with Asterisk and Asterisk-based communications systems, the dual span cards provide the best value in digital connectivity.
Dual span digital cards are available in PCI and PCI-Express form factors. 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.
