Rhino is a leading manufacturer of analog and digital interfaces for open
source IP PBX's such as Asterisk IP PBX. Currently Rhino offers several T1/E1
interfaces, there is the R1T1 single port T1/E1 PCI card, the R2T1 double port
T1/E1 PCI card and the R4T1 quad port T1/E1 PCI card.
