The Metrodata LH1000 enables the transmission of LAN frames across satellite links via serial modems.

LH1000 offering an Ethernet service over EIA530 and HSSI satellite equipment

This application shows an LH1000 offering Ethernet services over EIA530 and HSSI satellite modem equipment. The LH1000 supports high speed satellite modems with HSSI interfaces at data rates up to 110Mbps, or lower speed satellite modems with serial interfaces such as EIA530 at data rates up to 20Mbps. The LH1000 will even work with separate satellite modulators and demodulators even if these have different interface types (e.g. a HSSI satellite modulator and an EIA530 satellite demodulator).

The LAN interface is auto-sensing and supports 10M, 100M, full or half duplex operation. Manual selection of 100BaseT FD operation enables connection to fixed configuration router ports. The LAN interface has an RJ45 connector and offers automatic MDI/MDI-X interface selection to remove the need for cross-over cables. An efficient HDLC encapsulation is used which has address learning and filtering at up to 148810 packets per second. Rate decoupling is supported by means of a 1000 packet SDRAM buffer store, and no packets are lost providing that the sustained data rate is below the DTE serial port speed.

Two modem interfaces ports are provided, which can operate at asymmetric speeds since they are clocked using the DCE supplied Send Timing and Receive Timing signals from the DCE port on the connected modem, these are:

• HSSI DTE port with a standard 50-way SCSI-2 connector that operates at data rates of up to 110Mbps
• Multi-standard serial port with a 44-way high density D-Type connector at clock rates up to 20Mbps (EIA-530, X.21, V.35, RS449/ V.36 or RS-232, depending on the interface cable)

Status LEDs indicate speed and traffic flow on the Ethernet port, whilst unit configuration is performed via BIT switches on the base on the unit.

Further information can be found via the LH1000 product page.