The High SpeedSerial Interface (HSSI) is the de facto standard for DS-3 and STS-1 interfaces. The HSSI interface is also used for connections between routers or gateways and ATM switches.
HSSI is a serial interface that operates at transmission speeds of up to 52 Mbit/s. The connector used by HSSI is the 50 Mbit/s connector. As connector HSSI uses the 50-pin SCSI connector. The Data Exchange Interface (DXI) is used as the protocol for transmitting data between routers and ATM switching units via the HSSI interface.Data Service Unit (DSU).