WANPIPE S-series is a family of intelligent
multi-protocol WAN adapters that support data
transfer rates up to 4Mbps. All WAN protocols
supported by WANPIPE are implemented in firmware
and run on the card. An advantage of an
intelligent adapter is that it offloads the system
CPU and improves stability. By adding a Sangoma
WAN component to the Linux kernel, one can create
a powerful multi-T1/E1 router/firewall with proven
reliability of Linux.  Sangoma S-series cards
support an optional on board CSU/DSU that
eliminates all external components of a
traditional routing solution: T1/E1 lines can be
directly connected to the card.  WANPIPE supports
the following WAN protocols: Frame Relay, X25(API),
PPP, MULTILINK PPP, CHDLC, SS7(API), BISYNC(API), 
and SDLC(API). Furthermore, WANPIPE supports ADSL  
cards with drivers developed and optimized for Linux.   
WANPIPE contains custom API development packages for:
Credit card verification, Voice-over IP and Satellite
Comm. All device drivers are part of the standard
Linux Kernel distribution.